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Motion sickness

Travel sickness.

Peer reviewed by Dr Hayley Willacy, FRCGP Last updated by Dr Colin Tidy, MRCGP Last updated 16 Mar 2023

Meets Patient’s editorial guidelines

In this series: Health advice for travel abroad Travelling to remote locations Ears and flying Jet lag Altitude sickness

Motion sickness (travel sickness) is common, especially in children. It is caused by repeated unusual movements during travelling, which send strong (sometimes confusing) signals to the balance and position sensors in the brain.

In this article :

What causes motion sickness, how long does motion sickness last, motion sickness symptoms, how to stop motion sickness, natural treatments for motion sickness, motion sickness medicines, what can a doctor prescribe for motion sickness, what should i do if i'm actually sick, what is mal de debarquement syndrome.

Continue reading below

Motion sickness is a normal response to repeated movements, such as going over bumps or around in a circle, send lots of messages to your brain. If you are inside a vehicle, particularly if you are focused on things that are inside the vehicle with you then the signals that your eyes send to the brain may tell it that your position is not changing, whilst your balance mechanisms say otherwise.

Your balance mechanisms in your inner ears sense different signals to those that your eyes are seeing which then sends your brain mixed, confusing messages. This confusion between messages then causes people to experience motion sickness.

Is motion sickness normal?

Motion sickness is a normal response that anyone can have when experiencing real or perceived motion. Although all people can develop motion sickness if exposed to sufficiently intense motion, some people are rarely affected while other people are more susceptible and have to deal with motion sickness very often.

Triggers for motion sickness

Motion sickness can also be triggered by anxiety or strong smells, such as food or petrol. Sometimes trying to read a book or a map can trigger motion sickness. Both in children and adults, playing computer games can sometimes cause motion sickness to occur.

Motion sickness is more common in children and also in women. Fortunately, many children grow out of having motion sickness. It is not known why some people develop motion sickness more than others. Symptoms can develop in cars, trains, planes and boats and on amusement park rides, etc.

Symptoms typically go when the journey is over; however, not always. In some people they last a few hours, or even days, after the journey ends.

There are various symptoms of motion sickness including::

Feeling sick (nausea and vomiting).

Sweating and cold sweats.

Increase in saliva.

Headaches .

Feeling cold and going pale.

Feeling weak.

Some general tips to avoid motion sickness include the following.

Prepare for your journey

Don't eat a heavy meal before travelling. Light, carbohydrate-based food like cereals an hour or two before you travel is best.

On long journeys, try breaking the journey to have some fresh air, drink some cold water and, if possible, take a short walk.

For more in-depth advice on travelling generally, see the separate leaflets called Health Advice for Travel Abroad , Travelling to Remote Locations , Ears and Flying (Aeroplane Ear) , Jet Lag and Altitude Sickness .

Plan where you sit

Keep motion to a minimum. For example, sit in the front seat of a car, over the wing of a plane, or on deck in the middle of a boat.

On a boat, stay on deck and avoid the cafeteria or sitting where your can smell the engines.

Breathe fresh air

Breathe fresh air if possible. For example, open a car window.

Avoid strong smells, particularly petrol and diesel fumes. This may mean closing the window and turning on the air conditioning, or avoiding the engine area in a boat.

Use your eyes and ears differently

Close your eyes (and keep them closed for the whole journey). This reduces 'positional' signals from your eyes to your brain and reduces the confusion.

Don't try to read.

Try listening to an audio book with your eyes closed. There is some evidence that distracting your brain with audio signals can reduce your sensitivity to the motion signals.

Try to sleep - this works mainly because your eyes are closed, but it is possible that your brain is able to ignore some motion signals when you are asleep.

Do not read or watch a film.

It is advisable not to watch moving objects such as waves or other cars. Don't look at things your brain expects to stay still, like a book inside the car. Instead, look ahead, a little above the horizon, at a fixed place.

If you are the driver you are less likely to feel motion sickness. This is probably because you are constantly focused on the road ahead and attuned to the movements that you expect the vehicle to make. If you are not, or can't be, the driver, sitting in the front and watching what the driver is watching can be helpful.

Treat your tummy gently

Avoid heavy meals and do not drink alcohol before and during travelling. It may also be worth avoiding spicy or fatty food.

Try to 'tame your tummy' with sips of a cold water or a sweet, fizzy drink. Cola or ginger ale are recommended.

Try alternative treatments

Sea-Bands® are acupressure bands that you wear on your wrists to put pressure on acupressure points that Chinese medicine suggests affects motion sickness. Some people find that they are effective.

Homeopathic medicines seem to help some people, and will not make you drowsy. The usual homeopathic remedy is called 'nux vom'. Follow the instructions on the packet.

All the techniques above which aim to prevent motion sickness will also help reduce it once it has begun. Other techniques, which are useful on their own to treat motion sickness but can also be used with medicines if required, are:

Breathe deeply and slowly and, while focusing on your breathing, listening to music. This has been proved to be effective in clinical trials.

Ginger - can improve motion sickness in some people (as a biscuit or sweet, or in a drink).

There are several motion sickness medicines available which can reduce, or prevent, symptoms of motion sickness. You can buy them from pharmacies or, in some cases, get them on prescription. They work by interfering with the nerve signals described above.

Medicines are best taken before the journey. They may still help even if you take them after symptoms have begun, although once you feel sick you won't absorb medicines from the stomach very well. So, at this point, tablets that you put against your gums, or skin patches, are more likely to be effective.

Hyoscine is usually the most effective medicine for motion sickness . It is also known as scopolamine. It works by preventing the confusing nerve messages going to your brain.

There are several brands of medicines which contain hyoscine - they also come in a soluble form for children. You should take a dose 30-60 minutes before a journey; the effect can last up to 72 hours. Hyoscine comes as a patch for people aged 10 years or over. (This is only available on prescription - see below.) Side-effects of hyoscine include dry mouth , drowsiness and blurred vision.

Side-effects of motion sickness medicines

Some medicines used for motion sickness may cause drowsiness. Some people are extremely sensitive to this and may find that they are so drowsy that they can't function properly at all. For others the effects may be milder but can still impair your reactions and alertness. It is therefore advisable not to drive and not to operate heavy machinery if you have taken them. In addition, some medicines may interfere with alcohol or other medication; your doctor or the pharmacist can advise you about this.

Antihistamines

Antihistamines can also be useful , although they are not quite as effective as hyoscine. However, they usually cause fewer side-effects. Several types of antihistamine are sold for motion sickness. All can cause drowsiness, although some are more prone to cause it than others; for example, promethazine , which may be of use for young children on long journeys, particularly tends to cause drowsiness. Older children or adults may prefer one that is less likely to cause drowsiness - for example, cinnarizine or cyclizine.

Remember, if you give children medicines which cause drowsiness they can sometimes be irritable when the medicines wear off.

See the separate article called How to manage motion sickness .

There are a number of anti-sickness medicines which can only be prescribed by your doctor. Not all of them always work well for motion sickness, and finding something that works may be a case of trial and error. All of them work best taken up to an hour before your journey, and work less well if used when you already feel sick. See also the separate leaflet called Nausea (Causes, Symptoms, and Treatment) for more detailed information about these medicines .

Hyoscine patch

Hyoscine, or scopolamine, patches are suitable for adults and for children over 10 years old. The medicine is absorbed through your skin, although this method of medicine delivery is slow so the patch works best if applied well before your journey.

You should stick the patch on to the skin behind the ear 5-6 hours before travelling (often this will mean late on the previous night) and remove it at the end of the journey.

Prochlorperazine

Prochlorperazine is a prescription-only medicine which works by changing the actions of the chemicals that control the tendency to be sick (vomit), in your brain. One form of prochlorperazine is Buccastem®, which is absorbed through your gums and does not need to be swallowed. Buccastem® tastes rather bitter but it can be effective for sickness when you are already feeling sick, as it doesn't have to be absorbed by the stomach.

Metoclopramide

Metoclopramide is a tablet used to speed up the emptying of your tummy. Slow emptying of the tummy is something that happens when you develop nausea and vomiting, so metoclopramide can help prevent this. It prevents nausea and vomiting quite effectively in some people. It can occasionally have unpleasant side-effects, particularly in children (in whom it is not recommended). Metoclopramide is often helpful for those who tend to have gastric reflux, those who have slow tummy emptying because of previous surgery, and those who have type 1 diabetes. Your GP will advise whether metoclopramide is suitable for you.

Domperidone

Domperidone , like metoclopramide, is sometimes used for sickness caused by slow tummy emptying. It is not usually recommended for motion sickness but is occasionally used if other treatments don't help. Domperidone is not a legal medicine in some countries, including the USA.

Ondansetron

Ondansetron is a powerful antisickness medicine which is most commonly used for sickness caused by chemotherapy, and occasionally used for morning sickness in pregnancy. It is not usually effective for motion sickness. This, and its relatively high cost means that it is not prescribed for motion sickness alone. However, for those undergoing chemotherapy, and for those who have morning sickness aggravated by travel, ondansetron may be helpful.

If you're actually sick you may find that this relieves your symptoms a little, although not always for very long. If you've been sick:

Try a cool flannel on your forehead, try to get fresh air on your face and do your best to find a way to rinse your mouth to get rid of the taste.

Don't drink anything for ten to twenty minutes (or it may come straight back), although (very) tiny sips of very cold water, coke or ginger ale may help.

After this, go back to taking all the prevention measures above.

Once you reach your destination you may continue to feel unwell. Sleep if you can, sip cold iced water, and - when you feel ready - try some small carbohydrate snacks. Avoid watching TV (more moving objects to watch!) until you feel a little better.

The sensation called 'mal de debarquement' (French for sickness on disembarking) refers to the sensation you sometimes get after travel on a boat, train or plane, when you feel for a while as though the ground is rocking beneath your feet. It is probably caused by the overstimulation of the balance organs during your journey. It usually lasts only an hour or two, but in some people it can last for several days, particularly after a long sea journey. It does not usually require any treatment.

Persistent mal de debarquement syndrome is an uncommon condition in which these symptoms may persist for months or years.

Dr Mary Lowth is an author or the original author of this leaflet.

Further reading and references

• Spinks A, Wasiak J ; Scopolamine (hyoscine) for preventing and treating motion sickness. Cochrane Database Syst Rev. 2011 Jun 15;(6):CD002851.
• Lackner JR ; Motion sickness: more than nausea and vomiting. Exp Brain Res. 2014 Aug;232(8):2493-510. doi: 10.1007/s00221-014-4008-8. Epub 2014 Jun 25.
• Leung AK, Hon KL ; Motion sickness: an overview. Drugs Context. 2019 Dec 13;8:2019-9-4. doi: 10.7573/dic.2019-9-4. eCollection 2019.
• Zhang LL, Wang JQ, Qi RR, et al ; Motion Sickness: Current Knowledge and Recent Advance. CNS Neurosci Ther. 2016 Jan;22(1):15-24. doi: 10.1111/cns.12468. Epub 2015 Oct 9.
• Van Ombergen A, Van Rompaey V, Maes LK, et al ; Mal de debarquement syndrome: a systematic review. J Neurol. 2016 May;263(5):843-854. doi: 10.1007/s00415-015-7962-6. Epub 2015 Nov 11.

Article history

The information on this page is written and peer reviewed by qualified clinicians.

Next review due: 14 Mar 2028

16 mar 2023 | latest version.

Last updated by

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Motion Sickness

Motion sickness happens when the movement you see is different from what your inner ear senses. This can cause dizziness, nausea, and vomiting. You can get motion sick in a car, or on a train, airplane, boat, or amusement park ride. Motion sickness can make traveling unpleasant, but there are strategies to prevent and treat it.

Preventing motion sickness without medicine

Avoiding situations that cause motion sickness is the best way to prevent it, but that is not always possible when you are traveling. The following strategies can help you avoid or lessen motion sickness.

• Sit in the front of a car or bus.
• Choose a window seat on flights and trains.
• If possible, try lying down, shutting your eyes, sleeping, or looking at the horizon.
• Stay hydrated by drinking water. Limit alcoholic and caffeinated beverages.
• Eat small amounts of food frequently.
• Avoid smoking. Even stopping for a short period of time helps.
• Try and distract yourself with activities, such as listening to music.
• Use flavored lozenges, such as ginger candy.

Using medicines for motion sickness

Medicines can be used to prevent or treat motion sickness, although many of them cause drowsiness. Talk to a healthcare professional to decide if you should take medicines for motion sickness. Commonly used medicines are diphenhydramine (Benadryl), dimenhydrinate (Dramamine), and scopolamine.

Special Consideration for Children

Motion sickness is more common in children ages 2 to 12 years old.

Some medicines used to prevent or treat motion sickness are not recommended for children. Talk to your healthcare professional about medicines and correct dosing of medicines for motion sickness for children. Only give the recommended dosage.

Although motion sickness medicines can make people sleepy, it can have the opposite effect for some children, causing them to be very active. Ask your doctor if you should give your child a test dose before traveling.

More Information

Motion Sickness in CDC Yellow Book

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Motion Sickness

Last Updated June 2023 | This article was created by familydoctor.org editorial staff and reviewed by Deepak S. Patel, MD, FAAFP, FACSM

Table of Contents

What is motion sickness?

Motion sickness is a sick feeling triggered by movement. It occurs in cars, buses, trains, planes, or boats. It can occur on amusement rides or virtual reality experiences. Seeing the movement of others or things can trigger it. This condition is not life-threatening, however, it can make traveling unpleasant. Planning ahead helps prevent, avoid, or reduce the effects. Other triggers include:

• Being in the back seat of a car unable to see the horizon
• Reading in the car
• Not getting enough air in the car

Motion sickness is common in older people, pregnant women, and children between the ages of 5 and 12. Also, it’s common in people who have migraine headaches. It may be genetic. Once the motion stops, you’ll gradually feel better. In rare cases, the condition is triggered by a problem with your inner ear. This could be due to fluid buildup or an ear infection. Parkinson’s disease is another cause of the condition.

Symptoms can strike without warning. They can get worse quickly. You may feel sick to your stomach (nausea). Other symptoms include vomiting, pale skin, headache, a cold sweat, dizziness, and irritability.

What causes motion sickness?

Motion sickness is an imbalance between what you see and what you feel. In the car, the car is moving forward. However, your body is standing still. This imbalance is what causes you to feel sick.

You may notice a pattern of sickness when you travel. See your doctor if you experience motion sickness repeatedly. Your doctor will do a physical exam. They will look inside your ears and at your eyes. Your doctor will ask you questions about your health history before recommending treatment.

Prevention Tips

If you know you get motion sickness when traveling, plan ahead. These steps can prevent it or relieve the symptoms:

• Take motion sickness medicine one to two hours before traveling.
• Choose the right seat. The front passenger seat is best in the car. Choose the midpoint on a boat. Sit over the wing on a plane. Face forward on a train. Sit near a window on a train. These seats have fewer bumps. They allow you to see the horizon. If you are on a cruise, book a cabin in the front or middle of the ship. Request a room that is closest to the water level.
• Get plenty of air. Use the air conditioner or roll down the window in a car. Direct the vent toward you on a plane. Sit near a window when you’re on a covered boat.
• Avoid things you can’t change. For example, don’t ride on a speed boat. Waves and bumps can make you sick. If you can’t avoid it, take medicine in advance.
• Don’t read while riding in a car, plane, or boat. Look out the window at the horizon. Look at a distant object.
• Lie down when you feel sick.
• Avoid a heavy meal before or during travel. Eat small portions of plain food instead. Don’t eat greasy, spicy, or acidic foods before or during travel.
• Drink lots of water. Avoid alcohol.
• Talk to your doctor about different therapies. This might include pressure bands (worn on your wrist).

If your symptoms last longer than a few days, see your doctor.

Common medicines that treat motion sickness include Benadryl, Dramamine, and scopolamine. The American Academy of Family Physicians (AAFP) recommends scopolamine. It eases nausea and vomiting. It does not make you sleepy. A skin patch works best.

Antihistamines (one brand name: Benadryl) are helpful. However, these usually make you sleepy. Non-drowsy antihistamines are not effective in treating or preventing motion sickness. Another type of medicine is called antiemetics. These are used to treat nausea and vomiting.

Some of these medicines are prescription. Some are available over-the-counter. Talk to your doctor to determine which is best for you. These medicines work best when taken before you travel.

Once nausea begins, eat a few, plain crackers and drink clear, fizzy drinks (ginger ale is best) to relieve nausea.

Living with motion sickness

Planning ahead is the best advice for motion sickness. If your symptoms are mild, medicines are effective. Be sure to carry the proper medications with you while traveling.

Questions to ask your doctor

• Can medicine help after the symptoms start?
• Is motion sickness a sign of a more serious health problem?
• Can I take motion sickness medicine if I am pregnant or breastfeeding?
• Are motion sickness medicines safe to take with other medicines?

Centers for Disease Control and Prevention, Motion Sickness

National Institutes of Health, U.S. National Library of Medicine, Motion Sickness

Last Updated: August 11, 2021

This article was contributed by: familydoctor.org editorial staff and Alex Rice

Copyright © American Academy of Family Physicians

This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.

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Motion sickness

Motion sickness is feeling dizzy, or feeling or being sick when travelling by car, boat, plane or train. You can do things to prevent it or relieve the symptoms.

Check if you have motion sickness

Symptoms of motion sickness may include:

• feeling sick (nausea)
• feeling cold and going pale

How to ease motion sickness yourself

Do reduce motion – sit in the front of a car or in the middle of a boat look straight ahead at a fixed point, such as the horizon breathe fresh air if possible – for example, by opening a car window close your eyes and breathe slowly while focusing on your breathing distract children by talking, listening to music or singing songs break up long journeys to get some fresh air, drink water or take a walk try ginger, which you can take as a tablet, biscuit or tea don’t.

do not read, watch films or use electronic devices

do not look at moving objects, such as passing cars or rolling waves

do not eat heavy meals, spicy foods or drink alcohol shortly before or during travel

do not go on fairground rides if they make you feel unwell

A pharmacist can help with motion sickness

You can buy remedies from pharmacies to help prevent motion sickness, including:

• tablets – dissolvable tablets are available for children
• patches – can be used by adults and children over 10
• acupressure bands – these do not work for everyone

A pharmacist will be able to recommend the best treatment for you or your child.

Causes of motion sickness

Motion sickness is caused by repeated movements when travelling, like going over bumps in a car or moving up and down in a boat, plane or train.

The inner ear sends different signals to your brain from those your eyes are seeing. These confusing messages cause you to feel unwell.

Page last reviewed: 19 June 2023 Next review due: 19 June 2026

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Motion Sickness: Symptoms, Who's at Risk, and How to Prevent It

• Who Is at Risk
• Medications
• Health Conditions
• When to Get Help

Motion sickness ( kinetosis ) causes symptoms that include dizziness, nausea , and headache . It occurs when you're moving (in a car, for example) and your brain receives mixed signals from your body, inner ear, and eyes about its surroundings. For instance, if you're below deck on a boat, your inner ear may sense rolling waves but your eyes don't see them. It is also called vertigo or seasickness , and is common in both children and adults, though some risk factors make it more likely.

Motion sickness also can occur due to flight simulators, gaming, amusement park rides, and other "virtual reality" experiences. Self-driving (automated) vehicles also lead to episodes of motion sickness, as people read or work on other tasks rather than driving themselves.

This article explains the symptoms of motion sickness, their causes, and who's at risk. It presents tips on managing your symptoms and ways to prevent motion sickness before it happens.

Illustration by Maritsa Patrinos for Verywell Health

Who Is at Higher Risk for Motion Sickness?

Studies have shown that essentially everyone has the potential to get motion sickness because it's related to the vestibular system (and its ear-related role in motion, balance, and coordination).  It's common, with one study finding up to 25% of large ship passengers (even more on smaller boats) will develop motion sickness within two to three days of the start of an ocean voyage.

For some people, it starts right away, while others only feel sick after they’ve been moving for a long time. Some people are more likely to get motion sickness, including:

• Children aged 2 to 12 years (it can occur in younger children)
• Younger adults (compared with those over age 60)
• People who are pregnant
• People who get migraine headaches

Other factors that contribute to risk include:

• Alcohol and drug use
• Being sleep deprived
• Poor airflow in a vehicle
• Certain odors, including diesel fuel or cigarette smoke

A small study has shown that people who don't know when or how motion will occur may have more difficulty. Facing forward and watching the horizon may help deal with unpredictable motion and motion sickness.

Hormones and Motion Sickness

Females are more likely than males to get motion sickness, partly because of hormones.  Estrogen , the primary female sex hormone, can contribute to symptoms of nausea and dizziness. Studies have shown that the menstrual cycle, as well as estrogen drugs or supplements, can affect how someone experiences motion sickness.

Symptoms of Motion Sickness

Symptoms of motion sickness can vary significantly from person to person, and the degree to which you feel ill can be less severe or more severe than other people who suffer from vertigo.

Nausea and vomiting are common, but they are not the only symptoms of motion sickness. Other symptoms may include:

• Cold sweats and clammy hands
• Hyperventilation (rapid breathing)
• Sensitivity to smells
• Loss of appetite (clinically called anorexia )
• Excessive salivation
• Warm, flushed sensation

Sopite Syndrome

Some people have a subcategory of motion sickness called sopite syndrome. The main symptoms of sopite syndrome include:

• Drowsiness and lethargy
• Mild depression
• Reduced ability to focus on an assigned task

Nausea and vomiting are not symptoms of sopite syndrome, which is one way it’s different from more common types of motion sickness. Sopite symptoms also may occur alone, or they may last longer than other motion sickness symptoms. The precise cause remains unclear, but it's possible another mechanism (including ear-related) is at work.

Medications Can Cause Motion Sickness

Motion sickness symptoms (or their increased severity) can be caused by certain medications. Both prescription drugs and over-the-counter (OTC) medications can cause side effects that result in motion sickness symptoms even when you’re not actually moving.

Nausea, dizziness, and feeling off balance are the vertigo-like side effects that can occur with a wide range of medications. Some of the common medications that may cause these symptoms include:

• Antibiotics such as penicillin, Suprax (cefixime), and Cipro (ciprofloxacin)
• Estrogen-containing medications such as birth control pills and hormone replacement therapy
• Bisphosphonates , such as Binosto (alendronate)
• Lanoxin ( digoxin )
• Inbrija (levodopa)
• Narcotic pain medications like Kadian (morphine), OxyContin ( oxycodone ), or Hysingla ER (hydrocodone)
• Non-steroidal anti-inflammatories like Advil (ibuprofen) and Aleve (naproxen)
• Selective serotonin reuptake inhibitors such as Paxil (paroxetine), Prozac (fluoxetine), and Zoloft (sertraline)
• Statins such as Crestor (rosuvastatin) and Zocor (simvastatin)

Even if you do feel discomfort, do not skip or stop taking your medications without talking to your provider.

If you will be traveling and are worried about motion sickness occurring or being more severe with a medication, talk to your healthcare provider. They may say that you can safely take your dose in a different way (for example, at a different time) to help prevent symptoms. 

Motion Sickness Symptoms and Health Conditions

Motion sickness usually stops within eight hours of ending the activity or movement. If your symptoms do not get better when you stop moving, it could be another condition that causes the same symptoms as motion sickness and you should talk to your provider.

Conditions that can cause similar symptoms to motion sickness include:

• Fluid in the ear
• Benign paroxysmal positional vertigo (BPPV)
• Meniere’s disease

Talk to your healthcare provider about your symptoms to ensure an accurate diagnosis.

Treatment for Motion Sickness

There are a few treatment options for motion sickness. If you're taking medication before traveling, your healthcare provider may suggest a small dose before your trip to see how well it works.

Common medications for treating motion sickness include:

• Bonine (meclizine)
• Dramamine (dimenhydrinate)
• Phenergan ( promethazine )

Other options include:

• Anticholinergic drugs , including scopolamine (like the Transderm Scop patch)
• Benzodiazepines like Valium (diazepam)
• Dopamine receptor antagonists like Reglan (metoclopramide)

Acupuncture and other complementary medicine options, such as using the P6 pressure point to control nausea , exist for treating motion sickness. Some experts recommend ginger. However, there is limited research support for their benefits, and motion sickness remains easier to prevent than treat.

Preventing Motion Sickness

Changing your activities or position can help with motion sickness, though reading often leads to motion sickness. Lying down can help, as does limiting your visual input (for example, trees that seem to move as you pass them).

You can also try:

• Sitting in the front seat, if in a vehicle
• Turning air vents toward your face
• Keeping your head still
• Avoiding heavy meals or alcohol use

Natural remedies may help with motion sickness symptoms and their prevention. Try deep breathing exercises, which have been shown to help with seasickness in simulated exercises.

Physical therapy to help you adapt to motion may help, as can transcutaneous electrical nerve stimulation ( TENS ) using a small device that generates impulses. Cognitive behavioral therapy also may help to treat anxiety related to motion sickness.

Try Not to Think About Motion Sickness

Research has suggested that people who think they will get motion sickness are more likely to. You might be able to avoid or at least prevent motion sickness from getting worse by changing your thoughts and finding a distraction.

When to See a Healthcare Provider

Most people see a healthcare provider for motion sickness ahead of planned travel, in order to seek preventive treatment, but other situations do arise. The most common complications of motion sickness include vomiting that leads to dehydration and electrolyte imbalances , which can be treated easily. These conditions can, however, cause serious illness in some people.

Other conditions with symptoms similar to motion sickness include:

• Low blood sugar ( hypoglycemia ), which requires immediate care in people diagnosed with diabetes
• Stroke , a life-threatening condition that requires immediate intervention
• Traumatic head injury and concussion, commonly caused by sports injuries or accidents

If you feel sick after you hit your head or were in an accident, go to the emergency room or call 911.

Keep in mind that motion sickness usually goes away fairly quickly once you’ve stopped moving. If it’s been more than eight hours and you’re still having symptoms, call your provider.

While nausea and vomiting are common, they are not the only symptoms of motion sickness. Some people have other symptoms like fatigue and mood changes. Medications, hormones, and certain activities can make you more likely to get motion sickness.

It's easier to prevent motion sickness than treat it, so talk to your healthcare provider about medication and other treatment options.

If feelings of illness do not go away after the motion stops, your symptoms could be due to another condition. See your healthcare provider if you have motion sickness symptoms that last longer than eight hours.

Icahn School of Medicine at Mount Sinai. Motion Sickness .

Golding JF. Motion sickness . Handb Clin Neurol. 2016;137:371-390. doi:10.1016/B978-0-444-63437-5.00027-3

Li D, Chen L. Mitigating motion sickness in automated vehicles with vibration cue system . Ergonomics . 2022 Oct;65(10):1313-1325. doi:10.1080/00140139.2022.2028902.

Foster M, Singh N, Kwok K, Macefield VG. Vestibular modulation of skin sympathetic nerve activity in sopite syndrome induced by low-frequency sinusoidal motion. J Neurophysiol . 2020 Dec 1;124(6):1551-1559. doi: 10.1152/jn.00177.2020. 

Leung AK, Hon KL. Motion sickness: an overview . Drugs Context . 2019 Dec 13;8:2019-9-4. doi: 10.7573/dic.2019-9-4. 

Lipson S, Wang A, Corcoran M, Zhou G, Brodsky JR. Severe motion sickness in infants and children . Eur J Paediatr Neurol . 2020 Sep;28:176-179. doi:10.1016/j.ejpn.2020.06.010.

Laitinen L, Nurmi M, Ellilä P, Rautava P, Koivisto M, Polo-Kantola P. Nausea and vomiting of pregnancy: associations with personal history of nausea and affected relatives . Arch Gynecol Obstet . 2020 Oct;302(4):947-955. doi: 10.1007/s00404-020-05683-3. 

Jones MLH, Le VC, Ebert SM, Sienko KH, Reed MP, Sayer JR. Motion sickness in passenger vehicles during test track operations . Ergonomics . 2019 Oct;62(10):1357-1371. doi: 10.1080/00140139.2019.1632938.

Peddareddygari LR, Kramer PD, Hanna PA, Levenstien MA, Grewal RP. Genetic Analysis of a Large Family with Migraine, Vertigo, and Motion Sickness . Can J Neurol Sci . 2019 Sep;46(5):512-517. doi: 10.1017/cjn.2019.64.

Kuiper OX, Bos JE, Schmidt EA, Diels C, Wolter S. Knowing What's Coming: Unpredictable Motion Causes More Motion Sickness . Hum Factors . 2020 Dec;62(8):1339-1348. doi: 10.1177/0018720819876139.

Smith PF, Agrawal Y, Darlington CL. Sexual dimorphism in vestibular function and dysfunction . J Neurophysiol . 2019;121(6):2379-2391. doi:10.1152/jn.00074.2019

Centers for Disease Control and Prevention. Motion Sickness .

Varis N, Leinonen A, Perälä J, Leino TK, Husa L, Sovelius R. Delayed Drowsiness After Normobaric Hypoxia Training in an F/A-18 Hornet Simulator . Aerosp Med Hum Perform . 2023 Sep 1;94(9):715-718. doi:10.3357/AMHP.6238.2023. 

Altissimi G, Colizza A, Cianfrone G, et al. Drugs inducing hearing loss, tinnitus, dizziness and vertigo: an updated guide . Eur Rev Med Pharmacol Sci . 2020;24(15):7946-7952. doi:10.26355/eurrev_202008_22477

Seattle Children's Hospital. Motion sickness .

Hromatka BS, Tung JY, Kiefer AK, Do CB, Hinds DA, Eriksson N. Genetic variants associated with motion sickness point to roles for inner ear development, neurological processes and glucose homeostasis .  Hum Mol Genet . 2015;24(9):2700-2708. doi:10.1093/hmg/ddv028

Golding JF, Patel M. Meniere's, migraine, and motion sickness . Acta Otolaryngol. 2017;137(5):495-502. doi:10.1080/00016489.2016.1255775

Koch A, Cascorbi I, Westhofen M, Dafotakis M, Klapa S, Kuhtz-Buschbeck JP. The neurophysiology and treatment of motion sickness .  Dtsch Arztebl Int . 2018;115(41):687-696. doi:10.3238/arztebl.2018.0687

Stromberg SE, Russell ME, Carlson CR.  Diaphragmatic breathing and its effectiveness for the management of motion sickness . Aerosp Med Hum Perform. 2015;86(5):452-7.

Huppert D, Benson J, Brandt T. A historical view of motion sickness - a plague at sea and on land, also with military impact .  Front Neurol . 2017;8:114. doi:10.3389/fneur.2017.00114

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By Kristin Hayes, RN Kristin Hayes, RN, is a registered nurse specializing in ear, nose, and throat disorders for both adults and children.

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4 Common Types of Travel Sickness to Prepare for (Before Traveling)

29 May 2024

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Traveling to a new destination can be one of the most memorable chapters of your life… but it can also expose you to various health risks, including different forms of travel sickness. 

Understanding these common ailments (and how to prevent them) can often make-or-break your trip – especially for countries in Africa, Asia and South America (source: NYU Langone Health ).

In this article, we will discuss the 4 common types of travel sickness:

• Traveler’s diarrhea
• Motion sickness
• Altitude sickness

Being prepared for these conditions can make the difference between a wonderful trip, and a bedridden experience.

Which ones should you worry about?

Search by destination country ➜

This mosquito-borne disease is prevalent in many tropical and subtropical regions, particularly in parts of Africa, Asia, and South America. It can cause severe illness and, in some cases, be fatal if not treated promptly.

Symptoms of Malaria

Symptoms of malaria typically appear 7 to 30 days after being bitten by an infected mosquito. Common symptoms include high fever, chills, headache, muscle aches, and fatigue. Other symptoms may include nausea, vomiting, and diarrhea. In severe cases, malaria can cause jaundice, seizures, and coma.

How to Prevent Malaria

Preventing malaria involves several strategies:

• Use insect repellent containing DEET
• Try to minimize time spent in areas with open water, vegetation and moisture
• Wear long-sleeved clothing and long pants
• Sleep in an area with air conditioning, and if needed, under mosquito nets treated with insecticide

However, these measures are limited in effectiveness, and most travelers still get significant mosquito exposure after taking these steps.

Doctors and health experts urge travelers to seek anti-malaria medications before, during, and after their trip – as these medications can directly kill the malaria parasite.

Malarone is a common traveler favorite, due to very manageable side effects during travel. It’s taken 1-2 days before departure, and for 7 days after returning (other antimalarials like Doxycycline require 4 weeks after returning).

Treatment for Malaria

If you develop symptoms of malaria, seek medical attention immediately. Malaria can be treated with prescription medications, but early diagnosis and treatment are essential. The type of medication and duration of treatment depend on the species of Plasmodium parasite and the severity of the illness. Complete the full course of treatment even if symptoms improve to ensure the parasite is fully eradicated.

Is There a Vaccine?

Currently, there is no malaria vaccine available in the United States. Antimalarial medications should be the primary focus for travelers, as medications like Malarone are proven highly effective at preventing malaria transmission.

2. Traveler’s Diarrhea

Traveler’s diarrhea is a common illness that affects many travelers. It’s usually caused by consuming contaminated food or water. Bacteria such as E. coli, Salmonella, and Shigella are often responsible for this condition, but viruses and parasites can also be culprits. Traveler’s diarrhea can disrupt your trip and make you feel miserable.

See country-specific guidelines ➜

Symptoms of Traveler’s Diarrhea

Symptoms of traveler’s diarrhea include frequent, loose stools, abdominal cramps, nausea, and vomiting. In some cases, fever and dehydration may occur. Symptoms typically start within a few days of exposure and can last several days. While the illness is usually mild, it can be more severe in some individuals, particularly young children, the elderly, and those with weakened immune systems.

How to Prevent Traveler’s Diarrhea

To prevent traveler’s diarrhea, practice good hygiene and be cautious about what you eat and drink:

• Avoid drinking tap water and use bottled or purified water instead. 
• Be careful with ice cubes, as they may be made from tap water. 
• Eat only well-cooked food and avoid raw fruits and vegetables unless you can peel them yourself. 
• Wash your hands frequently with soap and water or use hand sanitizer to reduce the risk of infection.

Treatment for Traveler’s Diarrhea

If you develop traveler’s diarrhea, one of the top priorities is to stay hydrated. Drink plenty of fluids, such as oral rehydration solutions, to replace lost electrolytes. 

Many travelers prefer to obtain medications like Azithromycin before leaving, especially for high-risk countries. This antibiotic directly kills the bacteria causing traveler’s diarrhea, and is highly effective at getting you back on your feet to enjoy your trip.

3. Motion Sickness

Motion sickness is a common condition that can occur during travel by car, plane, boat, or train. It happens when there is a disconnect between the sensory signals your brain receives from your eyes, inner ears, and body. This sensory conflict can lead to symptoms of motion sickness, making your travel experience uncomfortable.

Symptoms of Motion Sickness

Symptoms of motion sickness include:

• Nausea and vomiting
• General feeling of discomfort

These symptoms can vary in intensity and may start suddenly. Some people are more prone to motion sickness than others, and it can affect travelers of all ages.

How to Prevent Motion Sickness

The most reliable way to avoid motion sickness is to carry Scopolamine patches with you (prescription required). These antimuscarinics work by blocking certain inhibitors from the nervous system. Apply this prescription patch behind your ear to prevent & alleviate nausea.

Beyond that, choose a seat where you are least likely to experience motion, such as the front seat of a car, over the wing on a plane, or the middle of a boat. Focus on the horizon or a fixed point in the distance. Avoid reading or using electronic devices while in motion, as this can worsen symptoms. Eating light, non-greasy meals before travel can also help.

Treatment for Motion Sickness

If you start to feel motion sickness, try to relax and take deep breaths. A Scopolamine patch can also be applied after symptoms begin, if you haven’t already applied one yet. 

Some travelers find small-to-moderate relief with the addition of natural remedies as well, such as ginger or acupressure wristbands. If motion sickness is severe or persistent, consult a healthcare provider for additional treatment options.

4. Altitude Sickness

This occurs when you ascend high altitudes (mostly mountains) too rapidly – although it can still cause negative effects during slow ascension too. It’s common in travelers visiting mountainous regions where the elevation is above 8,000 feet (2,400 meters). The reduced air pressure and lower oxygen levels at high altitudes can cause altitude sickness, affecting your ability to enjoy your trip.

Symptoms of Altitude Sickness

Symptoms of altitude sickness include fatigue, dizziness, headache, vomiting, nausea, and troubles breathing.  

These symptoms usually appear within hours of reaching high altitude. In rare cases, altitude sickness can lead to medical emergencies, such as high-altitude cerebral edema (HACE) or high-altitude pulmonary edema (HAPE).

How to Prevent Altitude Sickness

Preventing altitude sickness involves ascending gradually to allow your body to acclimatize. 

• Harvard Health recommends spending some time at a moderate altitude before going higher. We recommend at least 12 hours, and ideally 1-3 days.
• Stay hydrated by drinking plenty of fluids and avoid alcohol and caffeine, as they can exacerbate symptoms. 
• Eat a high-carbohydrate diet to maintain energy levels. 

If you have any doubts before ascending, medications such as Diamox ( found here ) are highly effective in preventing altitude sickness. Consult a doctor before your trip for further guidance.

Treatment for Altitude Sickness

If you develop symptoms of altitude sickness, descend to a lower altitude as soon as possible. Rest and avoid physical exertion until symptoms improve. Over-the-counter pain relievers can help alleviate headaches. In severe cases, oxygen therapy or medications such as dexamethasone may be necessary. Seek medical attention if symptoms worsen or do not improve with descent.

Need recommendations based on your country of travel?

Head to our homepage and select your country from the dropdown, which will show which ailments to prioritize avoiding. For example – some countries are at high risk for malaria, and some have a greater risk of traveler’s diarrhea.

This will give you a sense of which medications you may & may not want to consider, and will allow you to initiate a highly-affordable $30 consultation (as opposed to $50-100 with most other providers). 

When to Take Diamox for Altitude Sickness? (7 Scenarios)

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Motion sickness

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• Motion sickness is also known as travel sickness, car sickness or sea sickness.
• If you have motion sickness, you are likely to have nausea and may vomit and feel clammy.
• You can help prevent motion sickness by looking outside of the vehicle or focusing on the horizon.
• Symptoms usually end once the motion stops.
• You can try travel sickness treatments to help prevent motion sickness.

What is motion sickness?

Motion sickness is feeling unwell when moving on any type of transport. It is also known as ‘travel sickness’, 'car sickness' or 'sea sickness'. It is a normal response to certain types of movement.

There are a few ways to prevent and manage motion sickness.

What are the symptoms of motion sickness?

Nausea is the main symptom of motion sickness. But you might also experience other symptoms, including:

• vomiting or retching
• cold sweating
• lack of appetite
• dry mouth or excess saliva
• increased sensitivity to smell

If you are prone to motion sickness, you may quickly feel sick if you read a book or look at your phone when in a moving vehicle.

You might feel better after vomiting, and symptoms will generally improve once you stop moving. But you can also feel the after-effects of motion sickness for a few hours or a few days before fully recovering.

What causes motion sickness?

Motion sickness is thought to be caused by your senses being confused when what you see is different to the signals felt by your inner ear balance system .

If you are feeling anxious about travel, this can make motion sickness worse.

You can get motion sick when:

• travelling by car, bus, boat, train or aeroplane
• on amusement park rides
• playing virtual reality video games or simulations

Motion sickness is a common problem. It is most frequent in children aged between 2 and 12 years. If other family members get motion sickness, it is more likely that you will too.

If you already have a condition that causes nausea, such as morning sickness or migraines , you may be more likely to experience motion sickness.

How is motion sickness diagnosed?

You don’t need to see a doctor or get any tests for a diagnosis of motion sickness. There is a pattern of feeling unwell during travel or movement, so you will probably know if you have it.

If you often feel dizzy or nauseous at other times too, discuss this with your doctor.

ASK YOUR DOCTOR — Preparing for an appointment? Use the Question Builder for general tips on what to ask your GP or specialist.

How is motion sickness treated and prevented?

Practical tips.

Here are some tips for preventing motion sickness:

• Look out of the window, and focus on the horizon instead of looking at a book or a screen.
• Try to sit or lie still and rest your head on a pillow or headrest.
• Sit close to the front of a car, bus or train.
• If flying, sit still and close your eyes during take-off and landing.
• Listen to music and breathe mindfully .
• Open the window or air vent for fresh air.
• Eat lightly before and during the trip and avoid alcohol. Sip water instead.

Pressure bands worn on your wrists may help prevent motion sickness in some people.

If you are travelling by sea, after a few days of exposure to the motion you will likely adapt and get used to it.

You can try taking travel sickness medicines to prevent motion sickness. These may include:

• antihistamines
• antiemetics (medications to prevent and treat nausea and vomiting)

There might be side effects, such as drowsiness. Ask your pharmacist or doctor for advice on what to take. Getting advice is especially important:

• for children
• if you are taking other medicines
• if you are pregnant

If you are using a travel sickness medicine, you should take it about half an hour before travel. If you have motion sickness and you already feel nauseous, it is probably too late to take a medicine. Eating a few plain crackers or having a clear, fizzy drink may help.

If you or your child regularly suffer from motion sickness, make sure you have a container, plastic bags and wipes handy. Take a break for some fresh air when needed.

Resources and support

Ask your doctor or pharmacist how to prevent and treat motion sickness.

Visit the Australian Government Smart Traveller website for more travel health advice.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with 24 hours a day, 7 days a week.

FIND A HEALTH SERVICE — The Service Finder can help you find doctors, pharmacies, hospitals and other health services.

Learn more here about the development and quality assurance of healthdirect content .

Last reviewed: October 2023

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Travel-Related Diagnoses Among U.S. Nonmigrant Travelers or Migrants Presenting to U.S. GeoSentinel Sites — GeoSentinel Network, 2012–2021

Surveillance Summaries / June 30, 2023 / 72(7);1–22

Please note: This report has been corrected. An erratum  has been published.

Ashley B. Brown, MPH 1 ; Charles Miller, MSOR 1 ; Davidson H. Hamer, MD 2 ,3 ; Phyllis Kozarsky, MD 4 ; Michael Libman, MD 5 ; Ralph Huits, MD, PhD 6 ; Aisha Rizwan, MPH 7 ; Hannah Emetulu, MPH 7 ; Jesse Waggoner, MD 8 ; Lin H. Chen, MD 9 ,10 ; Daniel T. Leung, MD 11 ; Daniel Bourque, MD 3 ; Bradley A. Connor, MD 12 ; Carmelo Licitra, MD 13 ; Kristina M. Angelo, DO 1 ( View author affiliations )

Views: Views equals page views plus PDF downloads

Introduction, selected worldwide health event notifications, selected health event notifications in geosentinel, limitations, future directions, acknowledgments.

• Full Issue PDF

Problem/Condition: During 2012–2021, the volume of international travel reached record highs and lows. This period also was marked by the emergence or large outbreaks of multiple infectious diseases (e.g., Zika virus, yellow fever, and COVID-19). Over time, the growing ease and increased frequency of travel has resulted in the unprecedented global spread of infectious diseases. Detecting infectious diseases and other diagnoses among travelers can serve as sentinel surveillance for new or emerging pathogens and provide information to improve case identification, clinical management, and public health prevention and response.

Reporting Period: 2012–2021.

Description of System: Established in 1995, the GeoSentinel Network (GeoSentinel), a collaboration between CDC and the International Society of Travel Medicine, is a global, clinical-care–based surveillance and research network of travel and tropical medicine sites that monitors infectious diseases and other adverse health events that affect international travelers. GeoSentinel comprises 71 sites in 29 countries where clinicians diagnose illnesses and collect demographic, clinical, and travel-related information about diseases and illnesses acquired during travel using a standardized report form. Data are collected electronically via a secure CDC database, and daily reports are generated for assistance in detecting sentinel events (i.e., unusual patterns or clusters of disease). GeoSentinel sites collaborate to report disease or population-specific findings through retrospective database analyses and the collection of supplemental data to fill specific knowledge gaps. GeoSentinel also serves as a communications network by using internal notifications, ProMed alerts, and peer-reviewed publications to alert clinicians and public health professionals about global outbreaks and events that might affect travelers. This report summarizes data from 20 U.S. GeoSentinel sites and reports on the detection of three worldwide events that demonstrate GeoSentinel’s notification capability.

Results: During 2012–2021, data were collected by all GeoSentinel sites on approximately 200,000 patients who had approximately 244,000 confirmed or probable travel-related diagnoses. Twenty GeoSentinel sites from the United States contributed records during the 10-year surveillance period, submitting data on 18,336 patients, of which 17,389 lived in the United States and were evaluated by a clinician at a U.S. site after travel. Of those patients, 7,530 (43.3%) were recent migrants to the United States, and 9,859 (56.7%) were returning nonmigrant travelers.

Among the recent migrants to the United States, the median age was 28.5 years (range = <19 years to 93 years); 47.3% were female, and 6.0% were U.S. citizens. A majority (89.8%) were seen as outpatients, and among 4,672 migrants with information available, 4,148 (88.8%) did not receive pretravel health information. Of 13,986 diagnoses among migrants, the most frequent were vitamin D deficiency (20.2%), Blastocystis (10.9%), and latent tuberculosis (10.3%). Malaria was diagnosed in 54 (<1%) migrants. Of the 26 migrants diagnosed with malaria for whom pretravel information was known, 88.5% did not receive pretravel health information. Before November 16, 2018, patients’ reasons for travel, exposure country, and exposure region were not linked to an individual diagnosis. Thus, results of these data from January 1, 2012, to November 15, 2018 (early period), and from November 16, 2018, to December 31, 2021 (later period), are reported separately. During the early and later periods, the most frequent regions of exposure were Sub-Saharan Africa (22.7% and 26.2%, respectively), the Caribbean (21.3% and 8.4%, respectively), Central America (13.4% and 27.6%, respectively), and South East Asia (13.1% and 16.9%, respectively). Migrants with diagnosed malaria were most frequently exposed in Sub-Saharan Africa (89.3% and 100%, respectively).

Among nonmigrant travelers returning to the United States, the median age was 37 years (range = <19 years to 96 years); 55.7% were female, 75.3% were born in the United States, and 89.4% were U.S. citizens. A majority (90.6%) were seen as outpatients, and of 8,967 nonmigrant travelers with available information, 5,878 (65.6%) did not receive pretravel health information. Of 11,987 diagnoses, the most frequent were related to the gastrointestinal system (5,173; 43.2%). The most frequent diagnoses among nonmigrant travelers were acute diarrhea (16.9%), viral syndrome (4.9%), and irritable bowel syndrome (4.1%).

Malaria was diagnosed in 421 (3.5%) nonmigrant travelers. During the early (January 1, 2012, to November 15, 2018) and later (November 16, 2018, to December 31, 2021) periods, the most frequent reasons for travel among nonmigrant travelers were tourism (44.8% and 53.6%, respectively), travelers visiting friends and relatives (VFRs) (22.0% and 21.4%, respectively), business (13.4% and 12.3%, respectively), and missionary or humanitarian aid (13.1% and 6.2%, respectively). The most frequent regions of exposure for any diagnosis among nonmigrant travelers during the early and later period were Central America (19.2% and 17.3%, respectively), Sub-Saharan Africa (17.7% and 25.5%, respectively), the Caribbean (13.0% and 10.9%, respectively), and South East Asia (10.4% and 11.2%, respectively).

Nonmigrant travelers who had malaria diagnosed were most frequently exposed in Sub-Saharan Africa (88.6% and 95.9% during the early and later period, respectively) and VFRs (70.3% and 57.9%, respectively). Among VFRs with malaria, a majority did not receive pretravel health information (70.2% and 83.3%, respectively) or take malaria chemoprophylaxis (88.3% and 100%, respectively).

Interpretation: Among ill U.S. travelers evaluated at U.S. GeoSentinel sites after travel, the majority were nonmigrant travelers who most frequently received a gastrointestinal disease diagnosis, implying that persons from the United States traveling internationally might be exposed to contaminated food and water. Migrants most frequently received diagnoses of conditions such as vitamin D deficiency and latent tuberculosis, which might result from adverse circumstances before and during migration (e.g., malnutrition and food insecurity, limited access to adequate sanitation and hygiene, and crowded housing,). Malaria was diagnosed in both migrants and nonmigrant travelers, and only a limited number reported taking malaria chemoprophylaxis, which might be attributed to both barriers to acquiring pretravel health care (especially for VFRs) and lack of prevention practices (e.g., insect repellant use) during travel. The number of ill travelers evaluated by U.S. GeoSentinel sites after travel decreased in 2020 and 2021 compared with previous years because of the COVID-19 pandemic and associated travel restrictions. GeoSentinel detected limited cases of COVID-19 and did not detect any sentinel cases early in the pandemic because of the lack of global diagnostic testing capacity.

Public Health Action: The findings in this report describe the scope of health-related conditions that migrants and returning nonmigrant travelers to the United States acquired, illustrating risk for acquiring illnesses during travel. In addition, certain travelers do not seek pretravel health care, even when traveling to areas in which high-risk, preventable diseases are endemic. Health care professionals can aid international travelers by providing evaluations and destination-specific advice.

Health care professionals should both foster trust and enhance pretravel prevention messaging for VFRs, a group known to have a higher incidence of serious diseases after travel (e.g., malaria and enteric fever). Health care professionals should continue to advocate for medical care in underserved populations (e.g., VFRs and migrants) to prevent disease progression, reactivation, and potential spread to and within vulnerable populations. Because both travel and infectious diseases evolve, public health professionals should explore ways to enhance the detection of emerging diseases that might not be captured by current surveillance systems that are not site based.

Modern modes of transportation and growing economies have made traveling more efficient and accessible. This progress has resulted in a surge of international travel, including travel to remote destinations and lower-income countries ( 1 ). In 2019, a record 2.4 billion international tourist arrivals globally ( 2 ) were observed by the World Tourism Organization.

Four studies estimated that 43%–79% of travelers to low- and middle-income countries became ill with a travel-related health problem, some of whom needed medical care during or after travel ( 3 ). Certain groups (e.g., travelers visiting friends and relatives [VFRs] and migrants) are particularly at risk for acquiring travel-related diseases because of a lack of risk awareness, access to specialized health care and pretravel consultation, and trust in the health care system ( 4 , 5 ). In addition, travelers might introduce pathogens into new environments and populations, leading to the spread of novel and emerging infectious diseases ( 6 ). The 2019 measles outbreaks across Europe illustrated how travel and poor vaccination coverage among local populations can fuel an epidemic ( 7 ). These outbreaks resulted in the importation of measles to communities with low vaccination coverage in the United States, a country that had eliminated measles in 2000. The rapid spread of disease across international borders also was observed during the Ebola virus disease epidemic in West Africa during 2014–2016 ( 8 ) as well as during the COVID-19 pandemic ( 9 ). These events illustrate the dangers of introducing pathogens into geographic clusters of susceptible populations as well as the importance of vaccination and other preventative strategies to reduce the risk for importation and spread.

Studying illness among travelers improves case identification, clinical management, and public health prevention strategies and also helps to characterize the epidemiology of diseases and control their spread ( 10 ). Because international travel continues to increase, conducting surveillance and research regarding travel-related diseases will be instrumental in reducing global transmission. To identify travel-related diseases and facilitate rapid communication between clinicians and public health professionals globally, a surveillance system (e.g., GeoSentinel) is needed. Such connectivity can reduce the size of outbreaks while promoting the timely sharing of clinical insight regarding the diagnosis and treatment of patients.

The GeoSentinel Network (GeoSentinel) is a global, clinical-care–based surveillance and research network of travel and tropical medicine sites that monitors infectious diseases and other adverse health events that affect international travelers ( https://geosentinel.org/ ). Since its inception in 1995, GeoSentinel has remained at the forefront of travel-related sentinel surveillance and continues to refine its collection of epidemiologic data from ill travelers during and after travel.

This report describes GeoSentinel, key changes in its data collection, its successful detection of sentinel events, and future directions. This report also summarizes the data collected from migrants and returning U.S. nonmigrant travelers presenting for evaluation at a U.S. GeoSentinel site during 2012–2021. The findings in this report underscore the importance of global travel-related disease surveillance so that clinicians and public health professionals are aware of the most common travel-related illnesses and can develop improved treatment and prevention strategies.

The GeoSentinel Network

GeoSentinel is a collaboration between CDC and the International Society of Travel Medicine (ISTM) and was established in the United States in 1995 with nine U.S. sites ( 11 ). During 1996–1997, the GeoSentinel network expanded globally. GeoSentinel’s primary purpose is to coordinate multiple clinical-care–based sites that operate a global, provider-based emerging infections sentinel network, conduct surveillance for travel-related infections, and communicate and help guide public health responses ( 12 ). Sites collaborate to report disease or population-specific findings through retrospective database analyses and the collection of supplemental data to fill specific knowledge gaps.

Sites and Affiliate Members

As of December 2021, GeoSentinel comprised 71 sites in 29 countries located on six continents ( Figure 1 ). GeoSentinel sites are health care facilities led by site directors and codirectors who are medical professionals with expertise in travel and tropical medicine. GeoSentinel also includes 164 affiliate members (formerly referred to as network members) who report sentinel or unusual travel medicine cases but do not enter data into the GeoSentinel database.

Eligible Patients

Patient data can be entered into the GeoSentinel database if the patient has crossed an international border and was seen at a GeoSentinel site with a possible travel-related illness or, in the case of certain migrants, for screening purposes upon entry into their arrival country. Data from patients who develop a complication from pretravel treatments (i.e., adverse effect from vaccinations or antimalarial medication) also might be entered, even if the patients have not yet departed on their trip.

Data Collection

GeoSentinel sites use a standardized data collection form (Supplementary Appendix, https://stacks.cdc.gov/view/cdc/127681 ) to collect demographic, clinical, and travel-related information about patients and the illnesses acquired during travel. These data are collected electronically via a secure web-based data entry application based at CDC. Daily reports are generated for assistance in detecting events (i.e., unusual patterns or clusters of disease). The system emails these reports to both CDC and ISTM partners for review. If an unusual disease pattern or cluster of disease is detected, the GeoSentinel program manager sends an email to the site requesting additional information. Electronic validation is integrated into the database to reduce data entry errors and maintain data integrity. Whereas certain sites enter all travel-related cases into the GeoSentinel database, other sites only enter a convenience sample. Entry of cases into the GeoSentinel database and determination of travel association are at the discretion of the treating clinician. This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.* Ethics clearance has been obtained by sites as required by their respective institutions.

Selected Variables and Definitions

The GeoSentinel database contains information obtained from patients evaluated at GeoSentinel sites during and after international travel. The following definitions were used during the study period.

Citizen. A person who is a legally recognized national of a country.

Clinical setting. The timing of the visit related to travel.

• During travel. The trip related to the current illness is in progress. This category includes expatriates seen in their country of residence for illnesses likely acquired in that country or where the country of exposure cannot be ascertained.
• After travel. The trip related to the current illness has been completed. This category also includes expatriates who acquire an illness during travel outside their current country of residence and where the relevant exposure is related to travel.

Diagnosis and diagnosis type. Site directors choose from approximately 475 diagnoses classified as either etiologic or syndromic. A write-in option is available on the data collection form if the diagnosis is not on the list.

• Etiologic. This diagnosis type reflects a specific disease. The “diagnosis status” of etiologic diagnoses might be “confirmed” or “probable” (see Diagnosis status).
• Syndromic. This diagnosis type reflects symptom- or syndrome-based etiologies when a more specific etiology is not known or could not be determined as a result of use of empiric therapy, self-limited disease, or inability to justify additional diagnostic tests beyond standard clinical practice. The “diagnosis status” of all syndromic diagnoses is “confirmed” (see Diagnosis status).

Diagnosis status . The diagnosis is categorized in one of two ways on the basis of available diagnostic methods:

• Confirmed. The diagnosis has been made by an indisputable clinical finding (e.g., removal of larvae of tungiasis) or diagnostic test.
• Probable. The diagnosis is supported by evidence (including diagnostic testing) strong enough to establish presumption but not proof.

Expatriate. A person living in a destination with an independent residence and address and using the same infrastructure as local residents of the same economic class. Expatriates intend to remain in-country for ≥6 months and have no intention to legally change their citizenship or permanent residency status.

Main symptoms. The symptoms associated with the illness that was the reason for the clinic visit.

Migrant. A person who, at some time in their life, has emigrated from their country of birth and has previously or intends to legally change their citizenship or permanent residency status. The resident country is entered on the data collection form as the new home country.

Nonmigrant traveler. A person who is traveling for a purpose unrelated to migration.

Pretravel encounter. Any pretravel health visit or the receipt of travel-related health information.

Resident. A person who has their primary residence in a particular country.

Severity. The highest level of clinical care received for the travel-related diagnosis, including outpatient, inpatient ward, and inpatient intensive care unit (ICU) care.

Syndrome or system groupings of diagnoses. All GeoSentinel diagnoses are categorized into groups according to the type of syndrome or system affected ( Box 1 ).

Travel reason. Primary reason for travel related to the current illness ( Box 2 ).

Travel related. Designates the relation of the main diagnosis to the patient’s travel.

• Travel related. Used when the illness under evaluation, initially suspected to be travel-related, was determined to have been acquired during the patient’s travel.
• Imported infection. Used for infections acquired in the patient’s country of residence if exported to another country and then evaluated at a GeoSentinel site.
• Not travel related. Used when the illness under evaluation, initially suspected to be travel related, was determined to have been acquired before departure from or after returning to the home country.
• Not ascertainable . Used when the illness under evaluation, initially suspected to be travel related, was equally likely to have been acquired during the patient’s travel or before departing from or after returning to the residence country.

Changes to GeoSentinel Data Collection

During 2012–2021, multiple changes were made to the GeoSentinel data entry application ( Box 3 ). New fields and subfields that collect detailed information on patient types, diagnoses, and trip information were added to provide a complete profile of patients and their associated illnesses. Additional fields were added for diseases of interest to provide information (e.g., vaccination status, etiology [e.g., organism genus and species], and cause of death). Case definitions were developed for each diagnosis code, and data collection fields were refined on an ongoing basis to aid clinicians in classifying patients and diagnoses.

Internal validation is now used to ensure that data are collected uniformly and accurately among sites. The collection of diagnostic methods allows for validation of confirmed and probable cases, and quality assurance (QA) alerts prevent sites from classifying diagnoses as confirmed during data entry without required disease-specific diagnostic methods. Other QA alerts prevent the skipping of required fields as well as logical errors.

Before November 16, 2018, the variables of travel reason and exposure country (and region) were not linked to an individual diagnosis. Instances where patients had multiple unrelated diagnoses made it difficult to ascertain what information applied to which diagnosis. As a result, the data collection form and database were updated to specify travel reason and exposure country information for each individual diagnosis.

To fill knowledge gaps, enhanced surveillance projects were deployed throughout the analysis period to collect specific information about a disease or types of travelers that was not collected on the core data collection form. This included projects on antibiotic resistance for selected bacterial pathogens, rickettsioses, mass gatherings ( 13 ), rabies postexposure prophylaxis ( 14 ), planned and unplanned health care abroad ( 15 ), migrants ( 16 ), and respiratory illnesses related to COVID-19.

This report includes GeoSentinel data limited to unique patients with ≥1 confirmed or probable travel-related diagnosis who were evaluated after migration or travel at a GeoSentinel site in the United States during 2012–2021. Each patient might have multiple diagnoses. Patients must have been residents of the United States and evaluated after travel and within 10 years of migrating or returning from a trip outside of the United States. Only migrants with illnesses associated with their migration to the United States were included. The validity of diagnoses was verified by an infectious disease specialist using the diagnostic methods recorded by the sites. Descriptive analyses were performed on data from the 20 GeoSentinel sites in the United States ( Figure 2 ) with patients who met inclusion criteria. Frequencies were calculated on patient demographics (e.g., sex, age, country of birth, citizenship, and residence), travel-related information (e.g., reason for travel and country or region of exposure), diagnosis, diagnostic methods, year of illness onset, and severity of illness. Because of changes in the collection of travel-related information, a subanalysis was done on travel-related information before and after November 16, 2018. This information is reported separately. Geographic regions of exposure are classified based on modified UNICEF groupings ( https://data.unicef.org/regionalclassifications/ ). Data were managed using Microsoft Access (version 2208; Microsoft Corporation), and all analyses were performed using SAS (version 9.4; SAS Institute).

To demonstrate GeoSentinel’s ability to identify sentinel events and emerging disease patterns, three examples (i.e., dengue in Angola [2013], Zika in Costa Rica [2016], and yellow fever in Brazil [2018]) of emerging sentinel health threats that occurred during 2012–2021 are described. These health events were not limited to residents of the United States who were evaluated after travel and ≤10 years of migrating or returning from a trip outside of the United States. Therefore, these patients could be residents of any country and were seen at GeoSentinel sites both inside and outside of the United States.

During 2012–2021, a total of 198,120 unique patients were evaluated at GeoSentinel sites globally and included in GeoSentinel’s database ( Figure 3 ). Of these, 177,703 patients received at least one confirmed or probable travel-related diagnosis, of which 18,336 were reported from 20 GeoSentinel sites in the United States. Of the 17,538 patients evaluated by a clinician after travel, 17,389 were migrants or returning U.S. nonmigrant travelers to the United States, accounting for 25,973 travel-related diagnoses. The remaining 149 patients were non-U.S. residents and were excluded from the analysis. The results of migrants and returning nonmigrant travelers are reported separately.

Patient Demographics

Of the 17,389 patients who were included in this analysis, 7,530 (43.3%) were recent migrants to the United States; <1% of patients were expatriates. Of 7,527 migrants, 47.4% were female ( Table 1 ). The median age was 28.5 years (range = <19 years to 93 years), and the largest proportion of migrants was aged 19–39 years (35.9%). Of 4,672 patients with information available, 88.8% did not receive pretravel health information. Of 2,867 patients with information available on severity, a majority (89.8%) were seen as outpatients, 9.7% were seen in an inpatient ward, and <1% were seen in an ICU.

Of the 13,986 travel-related diagnoses among migrants, the most frequent were vitamin D deficiency (20.2%), Blastocystis (10.9%), latent tuberculosis (10.3%), strongyloidiasis (6.7%), and eosinophilia (5.8%) ( Table 2 ). A total of 43% of diagnoses fell into eight infectious or travel-related syndrome groupings including “other” (18.7%), gastrointestinal (15.7%), dermatological (2.0%), neurologic (1.9%), genitourinary (1.6%), febrile (1.5%), respiratory (1.5%), and musculoskeletal (<1%). No deaths or animal bites or scratches were reported ( Table 3 ).

Of the 2,614 diagnoses in the “other” grouping (Table 3), the most frequent were latent tuberculosis (55.2%), eosinophilia (30.8%), Chagas disease (3.8%), posttraumatic stress disorder (3.6%), and depression (2.9%). Of the 2,202 diagnoses in the gastrointestinal grouping, the most frequent were simple intestinal strongyloidiasis (41.6%), giardiasis (18.9%), Helicobacter pylori infection (8.4%), dientamoebiasis (6.9%), and schistosomiasis (6.5%). Of the 275 diagnoses in the dermatological grouping, the most frequent were fungal infection (42.6%), insect bite/sting (10.9%), rash of unknown etiology (10.2%), cutaneous leishmaniasis (5.8%), and leprosy (4.4%). Of the 263 diagnoses in the neurologic grouping, the most frequent were neurocysticercosis (76.8%), headache (16.4%), ataxia (1.5%), central nervous system tuberculosis (1.5%), and tuberculosis meningitis (1.1%). Of the 229 diagnoses in the genitourinary grouping, the most frequent were schistosomiasis (27.5%), chlamydia (15.3%), syphilis (11.4%), urinary tract infection (10.9%), and HIV (10.0%).

Among the 212 diagnoses in the febrile grouping (Table 3), the most frequent were malaria (25.5%), other extrapulmonary tuberculosis (13.2%), toxoplasmosis (8.0%), tuberculosis lymphadenitis (6.6%), and disseminated tuberculosis (5.2%). Malaria was diagnosed in 54 (<1%) migrants, and 88.5% did not receive pretravel health information (information available for 26 migrants). Of all species of malaria, Plasmodium falciparum was diagnosed most frequently (77.4%).

Among the 204 diagnoses in the respiratory grouping (Table 3), the most frequent was pulmonary tuberculosis (70.6%), which accounted for 68.9% of all active tuberculosis diagnoses; only 1% of migrants received a diagnosis of active tuberculosis disease. The remaining frequent diagnoses in the respiratory grouping were acute otitis media (4.9%), atypical pneumonia (3.4%), otitis externa (2.9%), and unspecified lobar pneumonia (2.9%). Of the 131 diagnoses in the musculoskeletal grouping, the most frequent were arthralgia (48.1%), trauma or injury (43.5%), osteomyelitis (1.5%), knee pain (1.5%), and sprain (1.5%).

Diagnostic Characteristics Before November 16, 2018

Among the 2,892 diagnoses with information available ( Table 4 ), the five most frequent regions of exposure were Sub-Saharan Africa (22.7%), the Caribbean (21.3%), Central America (13.4%), South East Asia (13.1%), and South Central Asia (9.2%). Among the 2,554 diagnoses with information available, the most frequent countries of exposure were Dominican Republic (7.9%), Thailand (6.5%), Haiti (6.2%), Ecuador (4.8%), and Myanmar (4.3%). Of 46 migrants with a malaria diagnosis, 89.3% were exposed in Sub-Saharan Africa (information available for 28 migrants).

Diagnostic Characteristics After November 16, 2018

Among the 2,012 diagnoses with information available (Table 4), the five most frequent regions of exposure were Central America (27.6%), Sub-Saharan Africa (26.2%), South East Asia (16.9%), the Caribbean (8.4%), and South America (7.0%). Among the 1,575 diagnoses with information available, the most frequent countries of exposure were El Salvador (11.2%), Thailand (10.7%), Honduras (9.1%), Guatemala (7.6%), and Dominican Republic (5.9%). Of seven migrants with a malaria diagnosis, all were exposed in Sub-Saharan Africa (information available for seven migrants).

Returning Nonmigrant Travelers

Among the 9,859 nonmigrant travelers returning to the United States, 55.7% were female and 75.3% were born in the United States. The median age was 37 years (range = <19 years to 96 years), and the largest proportion of nonmigrant travelers was aged 19–39 years (44.1%). Among the 8,967 patients with information available, 65.6% did not receive pretravel health information. Among the 5,884 patients with information available on severity, a majority (90.6%) were seen as outpatients, 8.4% were seen in an inpatient ward, and <1% were seen in an ICU. Approximately 1% of patients were expatriates, and 89.4% were U.S. citizens.

Of the 11,987 travel-related diagnoses of returning U.S. nonmigrant travelers (Table 3), 90.7% of diagnoses fell into nine infectious or travel-related syndrome groupings, including gastrointestinal (43.2%), febrile (16.7%), respiratory (13.0%), dermatological (8.9%), “other” (4.1%), animal bites or scratches (1.3%), genitourinary (1.4%), musculoskeletal (1.2%), and neurologic (<1%). The most frequent diagnoses (Table 2) were acute diarrhea (16.9%), viral syndrome (4.9%), irritable bowel syndrome (4.1%), campylobacteriosis (3.1%), and malaria (3.5%). Four deaths were reported, of which two were patients who received a diagnosis of severe P. falciparum malaria. Of the remaining two patients, one received a diagnosis of COVID-19 and the other received a diagnosis of acute unspecified hepatitis with renal failure.

Among the 5,173 diagnoses in the gastrointestinal grouping (Table 3), the most frequent were acute diarrhea (39.3%), irritable bowel syndrome (9.5%), campylobacteriosis (7.2%), giardiasis (5.5%), and chronic diarrhea (5.2%). Among the 2,001 diagnoses in the febrile grouping, the most frequent were viral syndrome (29.0%), malaria (21.0%), dengue (13.7%), chikungunya (6.4%), and unspecified febrile illness (5.0%). Among the 421 nonmigrant travelers with malaria of any species diagnosed, 80.8% had P. falciparum .

Among the 1,554 diagnoses in the respiratory grouping (Table 3), the most frequent were influenza-like illness (16.5%), upper respiratory tract infection (14.9%), acute bronchitis (11.9%), acute sinusitis (9.1%), and unspecified lobar pneumonia (8.4%). Among the 1,071 diagnoses in the dermatological grouping, the most frequent were insect or arthropod bite or sting (31.3%), rash of unknown etiology (8.8%), dermatitis (7.9%), skin and soft tissue infection (e.g., erysipelas, cellulitis, or gangrene [7.4%]), and superficial skin and soft tissue infection (6.0%). Among the 487 diagnoses in the “other” grouping, the most frequent were dehydration (18.7%), jet lag (17.9%), eosinophilia (11.7%), latent tuberculosis (8.8%), and anxiety disorder (7.6%).

Among the 173 diagnoses in the genitourinary grouping (Table 3), the most frequent were urinary tract infection (33.0%), schistosomiasis (11.6%), gonorrhea (9.3%), pyelonephritis (8.7%), and genital chlamydia (8.1%). Among the 142 diagnoses in the musculoskeletal grouping, the most frequent were arthralgia (19.7%), fracture (17.6%), myalgia (10.6%), trauma or injury (9.9%), and contusion (7.8%). Among the 105 diagnoses in the neurologic grouping, the most frequent were headache (26.7%), vertigo (12.4%), acute mountain sickness (10.5%), neurocysticercosis (9.5%), and dizziness (8.6%). Among the 153 diagnoses of bites or scratches, the most frequent were dog bite (50.3%), monkey bite (18.3%), other animal bite (6.5%), monkey exposure (5.9%), and dog exposure (3.9%).

Among the 9,919 diagnoses, 6,518 had information regarding travel reason ( Table 5 ). The most frequent reasons for travel were tourism (44.8%), VFR (22.0%), and business (13.4%). Among the 6,296 diagnoses with information available, the five most frequent regions of exposure were Central America (19.2%), Sub-Saharan Africa (17.7%), the Caribbean (13.0%), South East Asia (10.4%), and South America (9.4%). Among 5,920 diagnoses with information available, the most frequent countries of exposure were Mexico (12.5%), India (7.2%), Dominican Republic (5.3%), China (3.3%), and Costa Rica (3.0%).

Of 300 nonmigrant travelers with malaria, 70.3% were VFRs (information available for 232 nonmigrant travelers), and 88.6% were exposed in Sub-Saharan Africa. Of 163 VFRs with malaria, 70.2% did not receive pretravel health information (information available for 141 nonmigrant travelers), and 88.3% did not take malaria chemoprophylaxis (information available for 103 nonmigrant travelers).

Information regarding travel reason and exposure region was available for all 2,068 diagnoses (Table 5). The most frequent reasons for travel were tourism (53.6%), VFR (21.4%), business (12.3%), and missionary (6.2%). The five most frequent regions of exposure were Sub-Saharan Africa (25.5%), Central America (17.3%), South East Asia (11.2%), the Caribbean (10.9%), and South Central Asia (9.0%). Among the 1,894 diagnoses with information available, the most frequent countries of exposure were Mexico (13.2%), India (5.0%), Dominican Republic (4.2%), Philippines (3.0%), and Ethiopia (3.0%).

Of 121 nonmigrant travelers with malaria, 57.9% were VFRs and 95.9% were exposed in Sub-Saharan Africa. Of 70 VFRs with malaria, 83.3% did not receive pretravel health information (information available for 54 nonmigrant travelers), and none took malaria chemoprophylaxis (information available for three nonmigrant travelers).

Dengue in Angola, 2013

During April–May 2013, GeoSentinel sites in Canada, France, Germany, Israel, and South Africa reported 10 cases of dengue among travelers returning from Luanda, Angola. All patients had classic symptoms of dengue that included headache and joint pain and recovered without complication. Although dengue is endemic in Angola, before 2013, the last outbreak occurred during the 1980s. In the decades that followed, little was known regarding the epidemiology of dengue in Angola because of poor surveillance ( 17 ).

Although six cases of dengue had been reported to the Ministry of Health of Angola by April 1, 2013, the GeoSentinel cases, in combination with other imported cases to Portugal, were among the first indications of a large-scale outbreak. By May 31, there were 517 suspected cases and one death reported; all but two cases were in Luanda province ( 18 ). The GeoSentinel cases in Angola demonstrated that data on travelers’ adverse health events can aid in the detection of outbreaks, offering insight into the epidemiology of infectious disease in countries with suboptimal surveillance and reporting.

Zika in Costa Rica, 2016

On January 26, 2016, a GeoSentinel site in Massachusetts diagnosed dengue in a returned U.S. traveler from Nosara, Costa Rica. The patient returned to the United States with fever, rash, conjunctivitis, arthralgia, and headache; the patient also reported multiple mosquito bites. The patient was referred to a GeoSentinel site where antibody tests for Zika and dengue viruses were conducted by CDC. Plaque reduction neutralization antibody testing confirmed a diagnosis of Zika ( 19 ).

Zika virus emerged in the western hemisphere during 2014–2016 when outbreaks were reported from certain countries in the Americas and Caribbean ( 20 ). This case was the first case of Zika reported from Costa Rica, illustrating the continual geographic spread of a high-consequence pathogen. The Massachusetts GeoSentinel site detected and reported this sentinel case, and it also sent a networkwide notification, alerting clinicians to the risk for Zika in Costa Rica, a popular travel destination with no previous evidence of underlying circulation. By August 2017, a total of 1,920 cases were reported in Costa Rica, mirroring the trends of other countries in the region.

Yellow Fever in Brazil, 2018

In January 2018, a GeoSentinel site in the Netherlands reported a case of yellow fever in a Dutch man aged 46 years with recent travel to São Paulo state, Brazil. He had signs and symptoms of diarrhea, fever, headache, myalgia, and vomiting. By March 15, 2018, four additional GeoSentinel sites reported cases of yellow fever among travelers returning from Brazil, including two deaths. These five cases accounted for one half of all cases reported among international travelers to Brazil during this time. All patients were unvaccinated travelers, many of whom visited Ilha Grande ( 21 ).

Although yellow fever is endemic in Brazil, during 2016–2017 and 2017–2018, a higher incidence does not, by itself, indicate geographic expansion ( 22 ). Cases detected by GeoSentinel in early 2018 were among the first reported in newly identified regions of risk, confirming travelers as sentinels in the expansion of the outbreak and highlighting the importance of yellow fever vaccination in recommended regions ( 21 ).

GeoSentinel is the only surveillance network that operates a global, provider-based emerging infections sentinel network to conduct surveillance for travel-related infections and communicates with public health and clinical partners ( 11 ). From its inception in 1995 to 2011 ( 11 ), efforts were made to increase the size of the network, modernize data collection, and introduce internal validation to improve the quality of the data collected. Since 2012, GeoSentinel has expanded to 71 sites on six continents and has generated approximately 70 peer-reviewed publications. GeoSentinel also has undergone numerous methodologic changes aimed to improve data collection, the validity of resulting conclusions, and the provision of public health recommendations.

GeoSentinel data have been instrumental in the detection of sentinel events, as demonstrated by, but not limited to, the detection of expanded geographic area of yellow fever in Brazil ( 21 ), a large outbreak of dengue in Angola ( 17 ), and the first case of Zika in Costa Rica ( 19 ). These examples illustrate GeoSentinel’s ability to both identify emerging pathogens and communicate findings with clinicians and public health professionals around the world.

The most frequent diagnoses among migrants described in this analysis (e.g., vitamin D deficiency and latent tuberculosis) have been described elsewhere ( 23 , 24 ). Vitamin D deficiency might be because of reduced sun exposure caused by skin-covering clothing as well as low dietary intake ( 23 ). Acquisition of strongyloidiasis and latent tuberculosis might be from crowding, malnutrition, exposure to unsafe food and water, inadequate sanitation, and limited access to health care ( 25 ). Multiple presentations of Mycobacterium tuberculosis (e.g., pulmonary, extrapulmonary, lymphadenitis, disseminated, CNS tuberculoma, and meningitis) also were reported among migrants, highlighting that health care professionals should maintain a high degree of suspicion for M. tuberculosis infection among ill patients whose routine bacterial cultures do not yield a pathogen. Because the United States has the largest population of migrants in the world ( 26 ), health care professionals should continue to advocate for medical care for this underserved population, with the aim to prevent disease reactivation and subsequent spread to and within vulnerable populations.

Gastrointestinal illnesses remain a frequent cause of illness among travelers ( 27 ). In this analysis, acute diarrhea was the most frequent illness among nonmigrant travelers, accounting for 16.9% of their diagnoses. Previous studies have reported attack rates for acute diarrhea among travelers ranging from 30%–70%, most often caused by bacterial pathogens and transmitted because of poor hygiene practices in local restaurants ( 28 ). In other studies, travelers have reported not adhering to prevention practices and drinking unsafe tap water, consuming drinks with ice, eating salads, and consuming unpasteurized dairy products while abroad ( 29 ). Most acute diarrhea cases reported to GeoSentinel were of unknown etiology, illustrating the lack of use of specialized diagnostic tests or culture to determine the cause of diarrhea ( 30 ), despite the widespread availability of multiplex polymerase chain reaction tests for gastrointestinal pathogens ( 31 ), likely because the majority of cases of acute diarrhea resolve without the need for intervention ( 32 ).

Febrile illnesses were another frequent cause of illness among nonmigrant travelers in this analysis, of which viral syndromes and P. falciparum malaria were most frequent. Of nonmigrant travelers with malaria, a majority were exposed in Sub-Saharan Africa; the majority were VFRs, who infrequently received pretravel health advice or took malaria chemoprophylaxis. Inadequate pretravel preparation practices place VFRs at high risk for acquiring malaria during travel. Studies of African VFR travelers indicated they might not be able to afford health care visits, might feel unable to advocate for themselves in a health care setting, and might be culturally opposed to malaria chemoprophylaxis or other preventive measures (e.g., use of bed nets) because of concerns about offending their hosts or a low perception of risk ( 33 , 34 ). CDC recommends that all travelers going to an area where malaria is endemic take chemoprophylaxis before and during travel ( 35 ), but special considerations (e.g., improving accessibility or improving trust in the U.S. health care system) could be prioritized to ensure that VFRs are protected from malaria ( 33 , 36 ).

COVID-19 Pandemic

During 2020–2021, the number of patients presenting at U.S. GeoSentinel sites substantially decreased, mirroring worldwide declines in travel because of the COVID-19 pandemic and associated travel restrictions. Although GeoSentinel historically has been lauded for its ability to detect sentinel events in real time, GeoSentinel only retrospectively identified cases of influenza-like illness as COVID-19 among travelers who returned from China early in the pandemic. Although the outbreak began in China, a popular destination for U.S. travelers, in late 2019, U.S. GeoSentinel sites first reported COVID cases among travelers in March 2020. This lack of early identification of COVID-19 cases was likely because of three main reasons. First, daily reports were generated for assistance in detecting sentinel events, but these were simple line listings of cases and focused primarily on etiologic diagnoses; although cases of “viral illness” were reported from China to GeoSentinel as early as December 2019, these were not identified to be out of the ordinary. Surveillance systems (e.g., GeoSentinel) are most effective in detecting established etiologic illnesses, not novel pathogens ( 37 ). Second, delays in identification and available diagnostics for this novel pathogen meant that testing was not routinely available globally or at GeoSentinel sites early in the pandemic; therefore, etiologic COVID-19 diagnoses were only made retrospectively. Third, many cases of COVID-19 might have had mild symptoms similar to influenza, the common cold, and seasonal allergies, whose symptoms can be treated with over-the-counter medication. Thus, ill travelers might have opted to treat their symptoms at home and not seek health care or visited their primary care provider instead of a travel and tropical medicine site despite their recent travel.

To address these challenges, GeoSentinel has begun to explore other ways to detect and track novel pathogens more rapidly. GeoSentinel is developing automated, real-time data analytics (e.g., machine learning algorithms by likelihood of outbreak origin) to improve the ability to detect outbreaks and unusual clusters of disease together with more classical surveillance approaches ( 38 ).

The findings in this report are subject to at least six limitations. First, GeoSentinel data are not representative of all travelers. Although GeoSentinel tracks illnesses among travelers who are treated at GeoSentinel sites, data are entered at the discretion of the sites, which might lead to underreporting. Second, sites are not evenly dispersed globally and are predominantly located in Europe and North America. This pattern might reflect the travel attributes of persons from these continents. Third, GeoSentinel only collects data on ill travelers who seek care at GeoSentinel sites. The total numbers of travelers, ill travelers who do not seek care, or travelers who seek care outside of the GeoSentinel network is unknown. Thus, GeoSentinel data cannot be used to estimate risk, incidence, prevalence, or other rates because the number of well or unexposed travelers in the denominator is not known. Fourth, the United States does not have many large travel and tropical medicine centers (in comparison with Europe or Asia) and travelers, including migrants, might seek care external to the GeoSentinel network. Fifth, although changes in the information collected, methods, and the sites themselves have made data collection more robust, these changes also make the comparison of periods difficult and, in certain cases, inappropriate. Although all sites use the same standardized data collection form, data entry practices vary by site and over time. Finally, the large number of migrants reported from U.S. GeoSentinel sites might be the result of selection bias because of the migration medicine specialization of many U.S. sites. Diseases detected among migrants might be driven by routine screening on entry to the United States.

As of September 2021, GeoSentinel has incorporated research through its cooperative agreement between CDC and ISTM. This will allow GeoSentinel to conduct hypothesis-driven studies to help guide clinical and public health recommendations. Initial projects include investigation of fever of unknown etiology among travelers, neurocognitive outcomes among travelers with malaria, kinetics of human Mpox infections, and exploration of the distribution and types of antimalarial resistance using malaria genomics.

Over the past decade, GeoSentinel has contributed to the early detection of diseases among international travelers. The information about demographics, traveler types, and frequent diagnoses provides data that clinicians and public health agencies can use to improve pretravel preparedness and enhance guidance for the evaluation and treatment of ill travelers who seek medical care after international travel. The key successes and shortcomings of GeoSentinel serve as references to improve surveillance and expand the capability to detect sentinel events.

The following active members of the GeoSentinel Network contributed data from U.S. sites: Susan Anderson (Palo Alto, California); Kunjana Mavunda (Miami, Florida); Ashley Thomas (Orlando, Florida); Henry Wu (Atlanta, Georgia); Johnnie Yates (Honolulu, Hawaii); Noreen Hynes (Baltimore, Maryland); Anne Settgast, Bill Stauffer (St. Paul, Minnesota); Elizabeth Barnett (Boston, Massachusetts); Christina Coyle, Paul Kelly, Cosmina Zeana (Bronx, New York); John Cahill, Marina Rogova, Ben Wyler; (New York, New York); Terri Sofarelli (Salt Lake City, Utah). All maps were contributed by Marielle Glynn.

Corresponding author: Ashley B. Brown, Division of Global Migration and Quarantine, National Center for Emerging and Zoonotic Infectious Disease, CDC. Telephone: 678-315-3279; Email: [email protected] .

1 Division of Global Migration and Quarantine, National Center for Emerging and Zoonotic Infectious Disease, CDC; 2 Department of Global Health, Boston University School of Public Health, Boston, Massachusetts; 3 Section of Infectious Disease, Department of Medicine, Boston University Chobanian & Avedisian School of Medicine, Boston, Massachusetts; 4 Division of Infectious Diseases (Emerita), Department of Medicine, Emory University, Atlanta, Georgia; 5 J.D. MacLean Centre for Tropical Diseases, McGill University, Montreal, Canada; 6 Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Negrar, Verona, Italy; 7 GeoSentinel, International Society of Travel Medicine, Alpharetta, Georgia; 8 Department of Medicine, Emory University School of Medicine, Atlanta, Georgia; 9 Department of Medicine, Mount Auburn Hospital, Cambridge, Massachusetts; 10 Harvard Medical School, Boston, Massachusetts; 11 Division of Infectious Diseases, University of Utah School of Medicine, Salt Lake City, Utah; start highlight 12 Department of Psychology, Colorado State University, Fort Collins, Colorado; end highlight 13 Infectious Diseases, Orlando Health Medical Group, Orlando, Florida

Conflicts of Interest

All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

* 45 C.F.R. part 46.102(l)(2), 21 C.F.R. part 56; 42 U.S.C. §241(d); 5 U.S.C. §552a; 44 U.S.C. §3501 et seq.

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FIGURE 1 . GeoSentinel sites and affiliate members — GeoSentinel Network, 2012–2021*

* Sites = 71; affiliate members = 164.

BOX 1 . Syndrome and system groupings of diagnoses for surveillance — GeoSentinel Network, 2012–2021

• Adverse events to medication or vaccine
• Animal bites or scratches
• Dermatological: infectious or potentially travel related
• Dermatological: preexisting or chronic disease or comorbidity
• Febrile or systemic syndrome
• Gastrointestinal: infectious or potentially travel related
• Gastrointestinal: preexisting or chronic disease or comorbidity
• Genitourinary and STDs: infectious or potentially travel related
• Genitourinary and STDs: pre-existing or chronic disease or comorbidity
• Musculoskeletal: infectious or potentially travel related
• Musculoskeletal: pre-existing or chronic disease or comorbidity
• Neurological: infectious or potentially travel related
• Neurological: preexisting or chronic disease or comorbidity
• Other:* infectious or potentially travel related
• Other:* chronic disease or comorbidity
• Respiratory or ENT: infectious or potentially travel related
• Respiratory or ENT: pre-existing or chronic disease or comorbidity

Abbreviations: ENT = ears, nose, and throat; STD = sexually transmitted disease.

* Diseases that do not fall into system groupings.

BOX 2 . Reason for travel — GeoSentinel Network, 2012–2021

• Tourism (vacation): Includes all travel for tourism or leisure. Also includes travel that might involve visiting friends and relatives overseas if the traveler is not a first- or second-generation immigrant returning to his or her country of origin.
• ° Conference: Travel by an employed person for the purpose of attending a conference or convention
• ° Corporate or professional: Travel by an employed person for the purpose of carrying out business, attending meetings, or other work-related events
• ° Business or occupational — research: Travel by an employed person for the purpose of field work, laboratory work, or other type of academic research
• ° Business or occupational — other: Travel for the purpose of business or as part of one’s occupation but where the travel does not fit in the other specific categories of research, study, conference, or seasonal migrant work
• Seasonal or temporary work (migrant worker): Travel for the purpose of pursuing seasonal or other nonpermanent work because of economic opportunities in countries other than the person’s country of birth or place or permanent residence. These persons usually do not have any intention or permission to stay permanently in the country or region in which they are working.
• Student: Travel by a student for the purpose of study abroad, attending a student conference, research, or other educational purpose
• Migration: Main reason for travel is intent or need to resettle outside of birth country or country of secondary migration
• Providing medical care: Travel for the purpose of providing medical care
• VFR: Person is traveling from the region in which they are currently residing (usually as a migrant, expatriate, or long-term visitor) to their region of origin (e.g., a low-income country) to visit friends and relatives. This reason for travel includes persons who are travelling with a child/grandchild (second-generation VFRs) or parent and those traveling with a spouse or partner.
• Military: Main purpose is deployment to the country visited or to participate in military operations
• Missionary, humanitarian aid, volunteer, or community service: Travel to perform humanitarian work, community service, or take part in volunteer work (includes travel prompted by participation in a religious organization). If the purpose is primarily to provide health care, then the reason for travel should instead be providing medical care.
• Retirement: Travel for the purpose of retiring to a new location. Certain of these persons will be expatriates or long-term visitors.
• Planned medical care : Main purpose of travel is to obtain medical care
• Not ascertainable: Reason for travel cannot be ascertained or is unknown

Abbreviation: VFR = visiting friends and relatives.

BOX 3 . Changes to the GeoSentinel data entry application — GeoSentinel Network, 2012–2021

• Added date of illness onset
• Added preexisting conditions (e.g., HIV, cancer, or diabetes), including use of immunosuppressive drugs
• Added a requirement to mark a “primary diagnosis” if more than one diagnosis was entered
• Added new fields for diagnosis activity (active or resolved) and if diagnosed by screening

October 2015

• Modified function for “complete” records to include only those with infectious diagnoses or those that were travel related
• Added fields to capture the highest level of care required for the illness (severity), where the patient obtained pretravel information, and a write-in field for general comments
• Modified main presenting symptoms
• Updated reason for travel options
• ° Animal exposure
• ° Antibiotic taken during travel
• ° Attended mass gathering
• ° Blood or body fluid exposure
• ° Provided medical care
• ° Staying or eating in local homes
• ° Unplanned medical or dental care
• Added ability to capture diagnosis method(s)
• Created supplemental data form to collect antibiotic resistance data on nine pathogens ( Campylobacter spp., Escherichia coli , Klebsiella pneumoniae , Salmonella spp., S. enterica Typhi, S. enterica Paratyphi, Shigella spp., Staphylococcus aureus , and Streptococcus pneumoniae )
• Initiated special projects for mass gatherings and rabies postexposure prophylaxis

October 2016

• Modified main presenting symptoms and diagnostic methods
• Added ability to collect specimen type and organism genus and species
• Added geographic alerts for certain diseases (Barmah Forest virus, chronic Chagas disease, coccidioidomycosis, filariasis, malaria, paracoccidioidomycosis, Ross River virus, and schistosomiasis) that are reported from unexpected countries and regions
• Added required additional information for certain diseases, including vaccination status, etiology (e.g., organism genus and species), and cause of death
• Deployed enhanced surveillance migrant form to capture detailed information on migrants

November 2017

• Added subcategories for VFRs, identifying the VFR as the person, child or dependent, or spouse or partner
• Added option for secondary reason for travel and country of exposure for VFRs
• Added additional questions for certain diagnoses (i.e., malaria, leishmaniasis, and Zika)
• Added QA alerts to ensure that certain diagnoses meeting the case definition using the diagnosis methods to be marked confirmed
• Began collecting data for enhanced surveillance projects for rickettsioses, planned and unplanned healthcare abroad

August 2018

• Updated production database from Microsoft SQL Server 2008 to Microsoft SQL Server 2016

November 2018

• Combined supplemental migrant data collection form with main data collection form
• Updated expatriate and long-term visitor definitions and added subcategory options
• Added reason for travel, country of exposure, and region of exposure fields to each diagnosis
• Added imported infection as a travel-related option for migrants
• Added new project for respiratory illness in older travelers

October 2019

• Removed variables for primary diagnosis and patient type fields (inpatient, outpatient, tele-consult inpatient, and tele-consult outpatient)
• Removed student subchoices for travel reason field
• Added field for required medical evacuation
• Updated antibiotic resistance drug options
• Revised antibody diagnosis method to specify whether IgM or IgG
• Deployed enhanced surveillance project for respiratory illness in travelers related to COVID-19

August 2020

• Deployed enhanced surveillance project for sentinel identification of respiratory illness in travelers related to COVID-19

November 2021

• Updated COVID-19 vaccination status, including boosters

Abbreviations: IgG = immunoglobulin G; IgM = immunoglobulin M; QA = quality assurance; VFR = visiting friends and relatives.

FIGURE 2 . U.S. GeoSentinel sites* — GeoSentinel Network, 2012–2021

* Sites include Atlanta, GA (1); Baltimore, MD (2); Bethesda, MD (3); Birmingham, AL (4); Boston, MA (5); Bronx, NY (6); Bronx Lebanon, NY (7); Cambridge, MA (8); Hollywood, CA (9); Honolulu, HI (10); Miami, FL (11); New York City, NY (12); New York Northwest, NY (13); New York West, NY (14); Orlando, FL (15); Palo Alto, CA (16); Peekskill, NY (17); Salt Lake City, UT (18); Seattle, WA (19); and St. Paul, MN (20).

FIGURE 3 . U.S. nonmigrant travelers or migrants presenting to U.S. GeoSentinel sites — GeoSentinel Network, 2012–2021*

* A total of 149 non-U.S. residents were excluded from the analysis.

* Information available for 7,527 migrants and 9,852 other travelers. † Information available for 7,490 migrants and 9,793 other travelers. § Information available for 7,488 migrants and 9,841 other travelers. ¶ Information available for 4,672 migrants and 8,967 other travelers.

Abbreviations: CNS = central nervous system; ENT = ear, nose, and throat; STD = sexually transmitted disease. * The five most common diagnoses are provided for the most common travel-related syndrome and system groupings. † No deaths were observed among migrants; four deaths were observed among nonmigrant travelers.

* Information available for 2,892 diagnoses. † Five countries or regions with highest number of patient exposures. § Information available for 2,554 diagnoses. ¶ Information available for 1,575 diagnoses.

* Information available for 6,518 diagnoses. † Information available for 6,296 diagnoses. § Five countries or regions with highest number of patient exposures. ¶ Information available for 5,920 diagnoses. ** Information available for 1,894 diagnoses.

Suggested citation for this article: Brown AB, Miller C, Hamer DH, et al. Travel-Related Diagnoses Among U.S. Nonmigrant Travelers or Migrants Presenting to U.S. GeoSentinel Sites — GeoSentinel Network, 2012–2021. MMWR Surveill Summ 2023;72(No. SS-7):1–22. DOI: http://dx.doi.org/10.15585/mmwr.ss7207a1 .

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The science behind travel sickness, and how to avoid it

Gp offers advice on the best way to stay illness-free on long journeys.

For many families the summer holidays bring the opportunity to venture out on exciting road trips to far flung places.

But for some, long drives to holiday destinations or to visit family bring the unpleasant prospect of car sickness.

Ranging from a generally unwell feeling to nausea and vomiting, travel sickness can make holidays a misery for many but there are steps you can take to avoid it or at least reduce the symptoms.

What causes travel sickness?

According to GP and author, Dr Sarah Brewer, travel and motion sickness can be triggered by any form of transport and is caused when motion-detecting cells in the inner ears are excessively stimulated and send messages to the brain which don’t match the degree of movement detected by the eyes.

“Your eyes tell your brain that the environment is stationary but your balance organs say that it isn’t – this triggers travel sickness”, says Dr Brewer.

Read more: The 10 best traditional car games for the whole family

“Most people have experienced it at some point in their lives, however some people, particularly children, are especially sensitive as their nerve pathways involved are not fully developed. Before the age of ten, children are especially susceptible.”

According to research by Euro Car Parts, reading, watching a screen, travelling backwards and sitting in the back seat of a car are among the most common causes of feeling car sick. And small cars were the worst form of transport for instigating a bout of illness, to blame for 44 per cent of cases.

10 most common causes of travel sickness Reading (39%) Travelling backwards (38%) Sitting in the back seat (31%) Travelling while tired (17%) After drinking alcohol (16%) Watching a screen (15%) Dehydration (15%) Travelling while hungry (14.7%) Standing while travelling eg on public transport (11%) After eating (6%)

How to stop travel sickness

To help those who suffer from car sickness, Dr Brewer has come up with some tips to help avoid its onset or mimimise its effects

Watch what and when you eat and drink

When travelling, it can be tempting to buy quick and easy fast food from service stations en route. However, greasy, fatty and spicy food can cause nausea and trigger or worsen travel sickness. Likewise, alcohol can act as a diuretic and dehydrate you – further exacerbating your motion sickness.

You should however avoid travelling on an empty stomach – have a light meal instead 45 to 60 minutes before travelling, and top yourself up with light snacks which are bland and low in fat and acid.

Position is everything

If possible, offer to drive – drivers are less likely to suffer from travel sickness as they are concentrating on the outside. If driving isn’t an option, try to sit in the front seats and open the windows to get fresh air circulating.

Keep your attention focused on the distant horizon to reduce your sensory input. To help children, use car seats to ensure children can sit high enough to see out of the window.

To reduce nausea-inducing movement in other vehicles, try and sit between the wheels on buses or coaches where movement is less, or in the area above the wings on an aeroplane.

If all else fails, try medication

For travel sickness, prevention is easier than treating symptoms once they start. Try taking the antihistamine cinnarizine, which works on the vomiting centre in the brain, two hours before a journey, and it will reduce your susceptibility to motion sickness for at least eight hours.

If you are already feeling sick, however, you can suck a tablet rather than swallowing it for a more rapid effect. Just make sure you don’t take sedating travel sickness medication or drive if you feel drowsy.

If you prefer a more natural option, Dr Brewer recommends trying ginger tablets or wearing acupressure bands on your wrists.

Chris Barella, digital services director at Euro Car Parts said: “Unfortunately, motion sickness is something that most of us have dealt with at some point in our life and will probably have to continue to deal with.

“No one wants to experience that nauseous feeling while travelling. Hopefully the advice offered by Dr Brewer will help sufferers, particularly if you have no choice but to travel.”

Most Read By Subscribers

Medications for Motion Sickness

Other names: Sea Sickness

A disturbance of the inner ear that is caused by repeated motion

Drugs used to treat Motion Sickness

The medications listed below are related to or used in the treatment of this condition.

Frequently asked questions

• What is the Benadryl hat man?
• How long does Benadryl take to work?
• Does Benadryl help with or cause anxiety?
• Does Benadryl make you sleepy?
• Diphenhydramine Hydrochloride vs Citrate: What's the difference?
• Does Ginger interact with any drugs?
• Can you take Benadryl while pregnant?

View more FAQ

Alternative treatments for Motion Sickness

The following products are considered to be alternative treatments or natural remedies for Motion Sickness. Their efficacy may not have been scientifically tested to the same degree as the drugs listed in the table above. However, there may be historical, cultural or anecdotal evidence linking their use to the treatment of Motion Sickness.

• Dramamine Non Drowsy

Learn more about Motion Sickness

Care guides.

• Motion Sickness

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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NICHOLAS A. RATHJEN, DO, AND S. DAVID SHAHBODAGHI, MD, MPH

Am Fam Physician. 2023;108(4):396-403

Author disclosure: No relevant financial relationships.

Approximately 1.8 billion people will cross an international border by 2030, and 66% of travelers will develop a travel-related illness. Most travel-related illnesses are self-limiting and do not require significant intervention; others could cause significant morbidity or mortality. Physicians should begin with a thorough history and clinical examination to have the highest probability of making the correct diagnosis. Targeted questioning should focus on the type of trip taken, the travel itinerary, and a list of all geographic locations visited. Inquiries should also be made about pretravel preparations, such as chemoprophylactic medications, vaccinations, and any personal protective measures such as insect repellents or specialized clothing. Travelers visiting friends and relatives are at a higher risk of travel-related illnesses and more severe infections. The two most common vaccine-preventable illnesses in travelers are influenza and hepatitis A. Most travel-related illnesses become apparent soon after arriving at home because incubation periods are rarely longer than four to six weeks. The most common illnesses in travelers from resource-rich to resource-poor locations are travelers diarrhea and respiratory infections. Localizing symptoms such as fever with respiratory, gastrointestinal, or skin-related concerns may aid in identifying the underlying etiology.

Globally, it is estimated that 1.8 billion people will cross an international border by 2030. 1 Although Europe is the most common destination, tourism is increasing in developing regions of Asia, Africa, and Latin America. 2 Less than one-half of U.S. travelers seek pretravel medical advice. It is estimated that two-thirds of travelers will develop a travel-related illness; therefore, the ill returning traveler is not uncommon in primary care. 3 Although most of these illnesses are minor and relatively insignificant clinically, the potential exists for serious illness. The advent of modern and interconnected travel networks means that a rare illness or nonendemic infectious disease is never more than 24 hours away. 4 Travelers over the past 10 years have contributed to the increase of emerging infectious diseases such as chikungunya, Zika virus infection, COVID-19, mpox (monkeypox), and Ebola disease. 3

Although most travel-related illnesses are self-limiting and do not require medical evaluation, others could be life-threatening. 5 The challenge for the busy physician is successfully differentiating between the two. Physicians should begin with a thorough history and clinical examination to have the highest probability of making the correct diagnosis. Travelers at the highest risk are those visiting friends and relatives who stay in a country for more than 28 days or travel to Africa. Most travel-related illnesses become apparent soon after arriving home because incubation periods are rarely longer than four to six weeks. 3 , 6 The most common illnesses in travelers from resource-rich to resource-poor locations are travelers diarrhea and respiratory infections. 7 , 8 The incubation period of an illness relative to the onset of symptoms and the length of stay in the foreign destination can exclude infections in the differential diagnosis ( eTable A ) .

General questions should determine the patient’s pertinent medical history, focusing on any unique factors, such as immunocompromising illnesses or underlying risk factors for a travel-related medical concern. Targeted questioning should focus on the type of trip taken and the travel itinerary that includes accommodations, recreational activities, and a list of all geographic locations visited ( Table 1 3 , 6 , 9 and Table 2 3 , 6 ) . Patients should be asked about any medical treatments received in a foreign country. Modern travel itineraries often require multiple stopovers, and it is not uncommon for the casual traveler to visit several locations with different geographically linked illness patterns in a single trip abroad.

Travel History

Travelers visiting friends and relatives are at a higher risk of travel-related illnesses and more severe infections. 10 , 11 These travelers rarely seek pretravel consultation, are less likely to take chemoprophylaxis, and engage in more risky travel-related behaviors such as consuming food from local sources and traveling to more remote locations. 3 Overall, travelers visiting friends and relatives tend to have extended travel stays and are more likely to reside in non–climate-controlled dwellings.

During the clinical history, inquiries should be made about pretravel preparations, including chemoprophylactic medications, vaccinations, and personal protective measures such as insect repellents or specialized clothing. 12 , 13 Accurate knowledge of previous preventive strategies allows for appropriate risk stratification by physicians. Even when used thoroughly, these measures decrease the likelihood of certain illnesses but do not exclude them. 6 Adherence to dietary precautions and pretravel immunization against typhoid fever do not necessarily eliminate the risk of disease. Travelers often have no control over meals prepared in foreign food establishments, and the currently available typhoid vaccines are 60% to 80% effective. 14 Although all travel-related vaccines are important, the two most common vaccine-preventable illnesses in travelers are influenza and hepatitis A. 12 , 15

Travel duration is also an important but often overlooked component of the clinical history because the likelihood of illness increases directly with the length of stay abroad. The longer travelers stay in a non-native environment, the more likely they are to forego travel precautions and adherence to chemoprophylaxis. 3 The use of personal protective measures decreases gradually with the total amount of time in the host environment. 3 A thorough medical and sexual history should be obtained because data show that sexual contact during travel is common and often occurs without the use of barrier contraception. 16

Clinical Assessment

The severity of the illness helps determine if the patient should be admitted to the hospital while the evaluation is in progress. 3 Patients with high fevers, hemorrhagic symptoms, or abnormal laboratory findings should be hospitalized or placed in isolation ( Figure 1 ) . For patients with a higher severity of illness, consultation with an infectious disease or tropical/travel medicine physician is advised. 3 Patients with symptoms that suggest acute malaria (e.g., fever, altered mental status, chills, headaches, myalgias, malaise) should be admitted for observation while the evaluation is expeditiously completed. 13

Many tools can assist physicians in making an accurate diagnosis. The GeoSentinel is a worldwide data collection network for the surveillance and research of travel-related illnesses; however, this service requires a subscription. The network can guide physicians to the most likely illness based on geographic location and top diagnoses by geography. 4 For example, Plasmodium falciparum malaria is the most common serious febrile illness in travelers to sub-Saharan Africa. 17

Ill returning travelers should have a laboratory evaluation performed with a complete blood count, comprehensive metabolic panel, and C-reactive protein. Additional testing may include blood-based rapid molecular assays for malaria and arboviruses; blood, stool, and urine cultures; and thick and thin blood smears for malaria. 3 Emerging polymerase chain reaction technologies are becoming widely available across the United States. Multiplex and biofilm array polymerase chain reaction platforms for bacterial, viral, and protozoal pathogens are now available at most tertiary health care centers. 4 Multiplex and biofilm platforms include dedicated panels for respiratory and gastrointestinal illnesses and bloodborne pathogens. These tests allow for real-time or near real-time diagnosis of agents that were previously difficult to isolate outside of the reference laboratory setting.

Table 3 lists common tropical diseases and associated vectors. 3 , 6 , 18 Physicians should be aware of unique and emerging infections, such as viral hemorrhagic fevers, COVID-19, and novel respiratory pathogens, in addition to common illnesses. Testing for infections of public health importance can be performed with assistance from local public health authorities. 19 In cases of short-term travel, previously acquired non–travel-related conditions should be on any list of applicable differential diagnoses. References on infectious diseases endemic in many geographic locations are accessible online. The Centers for Disease Control and Prevention (CDC) Travelers’ Health website provides free resources for patients and health care professionals at https://www.cdc.gov/travel .

Febrile Illness

A fever typically accompanies serious illnesses in returning travelers. Patients with a fever should be treated as moderately ill. One barrier to an accurate and early diagnosis of travel-related infections is the nonspecific nature of the initial symptoms of illness. Often, these symptoms are vague and nonfocal. A febrile illness with a fever as the primary presenting symptom could represent a viral upper respiratory tract infection, acute influenza, or even malaria, typhoid, or dengue, which are the most life-threatening. According to GeoSentinel data, 91% of ill returning travelers with an acute, life-threatening illness present with a fever. 20 All travelers who are febrile and have recently returned from a malarious area should be urgently evaluated for the disease. 13 , 21 Travelers who have symptoms of malaria should seek medical attention, regardless of whether prophylaxis or preventive measures were used. Suspicion of P. falciparum malaria is a medical emergency. 13 Clinical deterioration or death can occur in a malaria-naive patient within 24 to 36 hours. 22 Dengue is an important cause of fever in travelers returning from tropical locations. An estimated 50 million to 100 million global cases of dengue are reported annually, with many more going undetected. 23 eTable B lists the most common causes of fever in the returning traveler.

Respiratory Illness

Respiratory infections are common in the United States and throughout the world. Ill returning travelers with respiratory concerns are statistically most likely to have a viral respiratory tract infection. 24 Influenza circulates year-round in tropical climates and is one of the most common vaccine-preventable illnesses in travelers. 3 , 12 Influenza A and B frequently present with a low-grade fever, cough, congestion, myalgia, and malaise. eTable C lists the most common causes of respiratory illnesses in the returning traveler.

Gastrointestinal Illness

Gastrointestinal symptoms account for approximately one-third of returning travelers who seek medical attention. 25 Most diarrhea in travelers is self-limiting, with travelers diarrhea being the most common travel-related illness. 7 Diarrhea linked to travel in resource-poor areas is usually caused by bacterial, viral, or protozoal pathogens.

The most often encountered diarrheal pathogens are enterotoxigenic Escherichia coli and enteroaggregative E. coli , which are easily treated with commonly available antibiotics. 26 Physicians should be aware of emerging antibiotic resistance patterns across the globe. The CDC offers up-to-date travel information in the CDC Yellow Book . 3 Although patients are often concerned about parasites, they should be reassured that helminths and other parasitic infections are rare in the casual traveler. 3

The disease of concern in the setting of gastrointestinal symptoms is typhoid fever. Physicians should be aware that typhoid fever and paratyphoid fever are clinically indistinguishable, with cardinal symptoms of fever and abdominal pain. 3 Typhoid fever should be considered in ill returning travelers who do not have diarrhea, because typhoid infection may not present with diarrheal symptoms. The likelihood of typhoid fever also correlates with travel to endemic regions and should be considered an alternative diagnosis in patients not responding to antimalarial medications. A diagnosis of enteric fever can be confirmed with blood or stool cultures. Although less common, community-acquired Clostridioides difficile should be considered in the differential diagnosis in the setting of recent travel and potential antimicrobial use abroad. 27

Another important travel-related pathogen is hepatitis A due to its widespread distribution in the developing world and the small pathogen dose necessary to cause illness. Hepatitis A is a more serious infection in adults; however, many U.S. adults have been vaccinated because the hepatitis A vaccine is included in the recommended childhood immunization schedule. 28 eTable D lists the most common causes of gastrointestinal illnesses in the returning traveler.

Dermatologic Concerns

Dermatologic concerns are common among returning travelers and include noninfectious causes such as sun overexposure, contact with new or unfamiliar hygiene products, and insect bites. The most common infections in returning travelers with dermatologic concerns include cutaneous larva migrans, infected insect bites, and skin abscesses. Cutaneous larva migrans typically presents with an intensely pruritic serpiginous rash on the feet or gluteal region. 3 Questions about bites and bite avoidance measures should be asked of patients with symptomatic skin concerns; however, physicians should remember that many bites go unnoticed. 29

Formerly common illnesses in the United States are common abroad, with measles, varicella-zoster virus infection, and rubella occurring in child and adult travelers. 3 Measles is considered one of the most contagious infectious diseases. More than one-third of child travelers from the United States have not completed the recommended course of measles, mumps, and rubella vaccines at the time of travel due to immunization scheduling. One-half of all measles importations into the United States comes from these international travelers. 30 Measles should always be considered in the differential because of the low or incomplete vaccination rates in travelers and high levels of exposure in some areas abroad. eTable E lists the most common infectious causes of dermatologic concern in the returning traveler.

Data Sources: A PubMed search was completed using the key words prevention, diagnosis, treatment, travel related illness, surveillance, travel medicine, chemoprophylaxis, and returning traveler treatment. The search was limited to English-language studies published since 2000. Secondary references from the key articles identified by the search were used as well. Also searched were the Centers for Disease Control and Prevention and Cochrane databases. Search dates: September 2022 to November 2022, March 2023, and August 2023.

The opinions and assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the U.S. Army, the U.S. Department of Defense, or the U.S. government.

The World Tourism Organization. International tourists to hit 1.8 billion by 2030. October 11, 2011. Accessed March 2023. https://www.unwto.org/archive/global/press-release/2011-10-11/international-tourists-hit-18-billion-2030

• Angelo KM, Kozarsky PE, Ryan ET, et al. What proportion of international travellers acquire a travel-related illness? A review of the literature. J Travel Med. 2017;24(5):10.1093/jtm/tax046.

Centers for Disease Control and Prevention. CDC Yellow Book: Health Information for International Travel . Oxford University Press; 2023. Accessed August 26, 2023. https://wwwnc.cdc.gov/travel/yellowbook/2024/table-of-contents

Wu HM. Evaluation of the sick returned traveler. Semin Diagn Pathol. 2019;36(3):197-202.

Scaggs Huang FA, Schlaudecker E. Fever in the returning traveler. Infect Dis Clin North Am. 2018;32(1):163-188.

Feder HM, Mansilla-Rivera K. Fever in returning travelers: a case-based approach. Am Fam Physician. 2013;88(8):524-530.

Giddings SL, Stevens AM, Leung DT. Traveler's diarrhea. Med Clin North Am. 2016;100(2):317-330.

Harvey K, Esposito DH, Han P, et al.; Centers for Disease Control and Prevention. Surveillance for travel-related disease–GeoSentinel Surveillance System, United States, 1997–2011. MMWR Surveill Summ. 2013;62:1-23.

Sridhar S, Turbett SE, Harris JB, et al. Antimicrobial-resistant bacteria in international travelers. Curr Opin Infect Dis. 2021;34(5):423-431.

Matteelli A, Carvalho AC, Bigoni S. Visiting relatives and friends (VFR), pregnant, and other vulnerable travelers. Infect Dis Clin North Am. 2012;26(3):625-635.

Ladhani S, Aibara RJ, Riordan FA, et al. Imported malaria in children: a review of clinical studies. Lancet Infect Dis. 2007;7(5):349-357.

Sanford C, McConnell A, Osborn J. The pretravel consultation. Am Fam Physician. 2016;94(8):620-627.

Shahbodaghi SD, Rathjen NA. Malaria. Am Fam Physician. 2022;106(3):270-278.

Freedman DO, Chen LH, Kozarsky PE. Medical considerations before international travel. N Engl J Med. 2016;375(3):247-260.

• Marti F, Steffen R, Mutsch M. Influenza vaccine: a travelers' vaccine?  Expert Rev Vaccines. 2008;7(5):679-687.

Vivancos R, Abubakar I, Hunter PR. Foreign travel, casual sex, and sexually transmitted infections: systematic review and meta-analysis. Int J Infect Dis. 2010;14(10):e842-e851.

Paquet D, Jung L, Trawinski H, et al. Fever in the returning traveler. Dtsch Arztebl Int. 2022;119(22):400-407.

Cantey PT, Montgomery SP, Straily A. Neglected parasitic infections: what family physicians need to know—a CDC update. Am Fam Physician. 2021;104(3):277-287.

Rathjen NA, Shahbodaghi SD. Bioterrorism. Am Fam Physician. 2021;104(4):376-385.

Jensenius M, Davis X, von Sonnenburg F, et al.; Geo-Sentinel Surveillance Network. Multicenter GeoSentinel analysis of rickettsial diseases in international travelers, 1996–2008. Emerg Infect Dis. 2009;15(11):1791-1798.

Tolle MA. Evaluating a sick child after travel to developing countries. J Am Board Fam Med. 2010;23(6):704-713.

Centers for Disease Control and Prevention. About malaria. February 2, 2022. Accessed August 21, 2022. https://www.cdc.gov/malaria/about/index.html

Wilder-Smith A, Schwartz E. Dengue in travelers. N Engl J Med. 2005;353(9):924-932.

Summer A, Stauffer WM. Evaluation of the sick child following travel to the tropics. Pediatr Ann. 2008;37(12):821-826.

Swaminathan A, Torresi J, Schlagenhauf P, et al.; GeoSentinel Network. A global study of pathogens and host risk factors associated with infectious gastrointestinal disease in returned international travellers. J Infect. 2009;59(1):19-27.

Shah N, DuPont HL, Ramsey DJ. Global etiology of travelers' diarrhea: systematic review from 1973 to the present. Am J Trop Med Hyg. 2009;80(4):609-614.

Michal Stevens A, Esposito DH, Stoney RJ, et al.; GeoSentinel Surveillance Network. Clostridium difficile infection in returning travellers. J Travel Med. 2017;24(3):1-6.

Mayer CA, Neilson AA. Hepatitis A - prevention in travellers. Aust Fam Physician. 2010;39(12):924-928.

Herness J, Snyder MJ, Newman RS. Arthropod bites and stings. Am Fam Physician. 2022;106(2):137-147.

Bangs AC, Gastañaduy P, Neilan AM, et al. The clinical and economic impact of measles-mumps-rubella vaccinations to prevent measles importations from U.S. pediatric travelers returning from abroad. J Pediatric Infect Dis Soc. 2022;11(6):257-266.

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These Are the 10 Nastiest Travel Diseases

What they are, what they do, and why you don't want them.

Wise travelers know to “get their jabs” before setting sail to some far off place. But why? What exactly are these diseases we’re all getting inoculated against? Will they lead to a grim and grisly death or just a good story to tell the grandkids?

Vagabondish is reader-supported. When you buy through links on our site, we may earn a small affiliate commission. Read our disclosure .

We combed CDC Travel and other health resources to gather a list of diseases and the most common travel illnesses, and all the reasons why you want to avoid them.

The Most Common Travel Illnesses

#1: cholera.

Forgive me for feeling that this disease sounded romantic when Gabriel Garcia Marquez included it in the title of his novel Love in the Time of Cholera — it is actually pretty nasty. You might pick it up in many parts of Africa and Asia, but it can occur anywhere with poor sanitation. You don’t want cholera because you’ll end up with diarrhea, vomiting, and fever, and it has the potential to be fatal, too.

Jabs are all well and good but the usefulness of the cholera vaccine is disputed — some experts say its effectiveness is only 50%. Since you pick up the cholera bacteria from contaminated food and water, you should avoid uncooked food and unbottled water.

© Ross_Angus

#2: Tetanus

While tetanus is the kind of disease that could happen to you anywhere, the highest number of reported incidences are in places like India and countries in central Africa. Tetanus is also called lockjaw for a good reason — it affects your nervous system and makes your muscles spasm and seize up.

But the good news about tetanus is that the vaccine is perfect. As long as you have your booster every ten years. Even in the United States, five people still die every year from tetanus, so it’s worth getting the jab even if you’re not planning to travel soon.

#3: Typhoid

Don’t ask me why, but typhoid has always sounded really dark and tragic to me. What I hadn’t realized is that it’s actually caused by the salmonella bacteria, and is transmitted if you consume food or water that’s been contaminated by the feces of an infected person. Nasty. It’s most commonly contracted in India and parts of Asia, Africa, and South America.

Typhoid is a disease that might hit you suddenly, but then develops slowly — you’ll get a fever, and after a week or so you might become delirious. In the vast majority of cases, it isn’t fatal, and the vaccine is also reasonably effective.

© jurvetson

#4: Dengue Fever

Once you know that dengue fever has been nicknamed break-bone fever or bonecrusher disease, you know it’s something you want to avoid. The initial fever is made worse by a headache, muscle and joint pains along with a really unattractive rash.

Dengue fever is most commonly found in tropical areas and parts of Africa. It’s a bit scarier because it also occurs in more developed parts of the tropics, like Singapore or Taiwan. Mosquitoes spread this disease and there’s no commercial vaccine yet, so use a repellent and nets to avoid getting bitten.

#5: Hepatitis

The various incarnations of hepatitis are running there way through the alphabet, but travelers need to worry most about types A and B.

Hepatitis A is found in developing countries including India, Mexico, Latin America and parts of Africa and is a nasty infection of the liver. Symptoms include fever, nausea and jaundice for a week or up to several months, but it’s rarely fatal, and it is usually picked up from contaminated food and water or close contact with infected people.

Hep A’s big, bad brother Hepatitis B is found in similar regions, plus the Middle East and some Pacific Islands, and can lead to a whole heap of liver damage, cirrhosis of the liver and liver cancer. Fortunately, it’s also harder to catch, as it’s usually transmitted only via blood, shared needles and body fluids. You have to plan ahead if you’re traveling to a Hepatitis B risk area because vaccinations must start over six months before you travel. And this one can kill you.

#6: Malaria

This is one of the trickiest diseases (and one of the most common travel illnesses) to deal with while traveling abroad. Most of the medication needs to be taken before, during, and after your trip, and some of it can have unpleasant side effects. These days, malaria is found in at least a hundred countries — the Center for Disease Control has quite a handy risk map to check your destination.

Malaria Control Sign © otisarchives2

You can catch malaria from a mosquito bite, so covering up against these nasties is a must along with taking medication. Symptoms including a fever and something similar to the flu; it’s not usually fatal, but it can be. Scientists are still working on a vaccine against malaria, and that’s something that would be a big benefit to travels if they figured it out successfully.

#7: Yellow Fever

Another mosquito-borne nasty is yellow fever. It’s among the most common travel illnesses, mostly found in the tropical parts of South America and Sub-Saharan Africa.

Victims usually end up with jaundice, hence “yellow” fever. But while yellow fever can also kill you, it’s easier to prevent because the vaccination is nearly always effective, and only needs to be administered a couple of weeks before you travel.

#8: HIV / AIDS

While definitely not only a travelers’ disease, HIV is becoming a serious issue for travelers in Africa and South East Asia where it’s become scarily prevalent. Yet a lot of carriers don’t realize they have the virus. As a result, many of these people will remain untreated and consequently, die of AIDS.

Fortunately, reducing your risk of contracting HIV as a traveler is mostly a matter of common sense and taking care. Avoid casual sex, use your own, high-quality condoms if you have sex with someone you meet, don’t share needles or syringes or get a tattoo or piercing. Common sense, right?

#9: Japanese Encephalitis

Those mosquitoes are responsible for all manner of unfriendly diseases and Japanese encephalitis is definitely one to avoid. It affects the central nervous system, causing severe flu-like symptoms, and it can be fatal. The vaccine is quite effective, especially if you get the recommended two doses.

And contrary to the suggestion in its name, Japanese encephalitis isn’t limited to Japan at all — it’s most common in agricultural regions of countries like Vietnam, Cambodia, India, Nepal and Malaysia. Again, cover up against mosquitoes if you’re traveling in these areas.

#10: Meningitis

Meningitis is another common travel illness/disease that’s not exclusively the province of travelers or the third world — it can occur, rarely, in Western countries too. However, the “Meningitis Belt” is an area stretching across Africa from Senegal to Ethiopia where it’s relatively common for large outbreaks of meningococcal meningitis to occur.

Meningitis usually comes from contact with, ahem, nose or throat discharges from someone who’s infected. This time you’ll also start with a fever, but usually progress to vomiting, a stiff neck and a bad purple rash. There are vaccinations available (but not against all kinds), or antibiotics can treat it. If you have suspicion of having meningitis, it’s the sort of thing you want to check out immediately — untreated cases are often fatal.

So, there you have it: the most common travel illnesses. If you get your shots before you travel, and you’re relatively careful on the road, the worst case scenario is usually just a minor version of these nasty diseases. But remember, I’m not a doctor, so check with yours before you head off into the danger zone.

For more info on the most common travel illnesses and foreign diseases, check out:

• CDC Yellow Book 2018: Health Information for International Travel
• CDC’s Travelers’ Health Resource
• The Travel Doctor
• World Health Organization’s International Travel and Health Report

What about “home sickness”?? Seriously though; interesting post.

Good point. That’s perhaps the worst sickness of all.

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Great roundup Amanda. Will ‘stumble’ it.

It’s funny though… I think Aussies are a bit obsessed about getting their jabs. I’m one and I know I was when I lived there. As a young backpacker, I’d go off and spend a couple of hundred bucks getting whatever the doctor ordered. I’ve lived overseas for 10 years and I travel constantly (I’m a travel writer) and I haven’t had a shot of anything in 10 years and I’ve travelled all over the Middle East, Asia, Africa, and not caught a thing. And I just don’t know anyone, ot even frequent travellers who go to dodgy countries, who get shots anymore – there just isn’t the level of awareness around in some countries that there is down under. Interestingly, I caught Malaria around 12 years ago when I was in the Amazon and had taken all the precautions.

Interesting point, Lara … although I have to say when I lived in Germany my GP was paranoid about giving me tons of jabs – even just to go camping in Germany, and when I said I was going to Africa … she was jumping on their special intranet site to get all the latest info. So it’s not just an Aussie thing, but yep, we do like getting jabs!

Hi, You forget to mention that Rio de Janeiro now is passing for a Dengue epidemia. And many places in North Brazil:includes Amazonia have problems with: Malaria, Yellow Fever and Dengue. YF and Dengue is presente in all places.

Thank you this was very helpful

It is important that you get every vaccine for these diseases before even going anywhere in the globe.

No vaccine available yet for malaria though unfortunately.

Thanks Izabel, that’s true. I’ve also been reading Dengue warnings for New Caledonia recently. It definitely pays to check out the current warnings for your destination.

Getting stuck with needles doesn’t sound as bad now does it!!

Dengue was pretty rife when I lived in Saigon. Some of the TEFL crowd were out for weeks with it. An addiction to 30 Rock is all they got to cure it.

While doctors at home can certainly be too conservative, some of the jabs are necessary. I won’t let my yellow fever vaccine lapse if I’m travelling, in part because it sucks to get it, but also because some countries won’t let you in the country if you don’t have proof of the vaccine. (I watched travellers get turned away at the border of Bolivia because they didn’t have proof of the vaccine.) And I wouldn’t mess around with Hepatitis (I keep my A/B vaccines up to date too).

What about amoebic dysentery? Speaking from experience, it is not the most fun I’ve had on my travels :)

Thanks for sharing – incredibly helpful!

Vaccinations are such a controversial issue. Before an impromptu trip to Costa Rica last spring, I had to decide whether it was worth it to put harmful chemicals in my body or risk getting sick. I ended up opting to skip getting jabbed and didn’t have any issues over the sixteen day trip. That said, I wonder if I would be so “risky” while going to other places or going somewhere long-term…

I’ve been travelling for many years and constantly for the last 3 years, i’ve been to 85 countries. I have my tetanus up to date and that’s it, no other jabs! and have never been sick. I’ve just spent 7 months in Central America including the Amazon jungle never even got sickness or diarrhoea. I might be on the extreme but sometimes you can be over cautious!

That’s why as a traveler, we should always be vaccinated and keep a healthy life so there will be minimal chance for us to get sick. Thanks for this very informative article.

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A Guide to Managing Covid This Summer

Here’s what to know about the “FLiRT” variants of the virus, as well as symptoms, testing and treatment.

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By Dani Blum

As new variants of the coronavirus continue to gain traction, doctors and researchers are bracing for a potential rise in cases this summer. Two of these variants, KP.3 and KP.2, now account for over half of all cases , and data from the Centers for Disease Control and Prevention shows that Covid-related emergency room visits, deaths and hospitalization rates have risen.

Here’s what to know about symptoms, testing and treatment if you do fall ill:

Symptoms to watch out for

There’s no evidence that symptoms of the new dominant variants, including those collectively known as the “FLiRT” variants , are any different than other recent strains of the virus, said Aubree Gordon, an infectious disease epidemiologist at the University of Michigan.

The symptoms still include sneezing, congestion, headaches, sore muscles, nausea or vomiting. Many people also report exhaustion and a general “blah” feeling.

In general, the more immunity you’ve built up from vaccination or past infections, the milder your next bout with the virus is likely to be. (Though it’s possible to experience more intense symptoms with a new infection than you’ve had in past Covid cases.)

The symptoms of Covid can look similar to those caused by allergies or other infections. The best way to tell the difference is to test.

When (and how) to test

In an ideal world, experts said, people would take a Covid test as soon as they develop symptoms or learn they were exposed, and then test again a day or two later. But if you only have a limited number of at-home rapid tests, there are a few ways to maximize their usefulness: Test immediately if you have a fever and a cough, said Dr. Davey Smith, an infectious disease specialist at the University of California, San Diego.

If you have other symptoms but few tests on hand, you may want to wait a few days to test, to reduce the chance of a false negative. People who are immunocompromised, older or who have underlying health issues may want to test as soon as they feel sick or learn they were exposed, so they can start taking Paxlovid to reduce the severity of the illness, said Dr. Paul Auwaerter, clinical director of the division of infectious diseases at Johns Hopkins Medicine.

If you’ve had symptoms for more than three days but are still testing negative, it’s unlikely you’ll ever test positive on an at-home test, Dr. Gordon said — either because you do not have Covid, or because you are shedding amounts of the virus that are too low for a rapid test to pick up.

If you’re waiting to test, you should take precautions in the meantime to minimize the potential spread of the virus, like wearing a mask in public and isolating from others, said Dr. Paul Sax, the clinical director of the division of infectious diseases at Brigham and Women’s Hospital.

Before using a test, check its expiration date. If it’s past the date, you can see whether it’s still usable by going through the F.D.A. database of tests. Be mindful in the summer months about where Covid tests are stored; leaving them in extreme heat for several days may make them less accurate. Health officials have also advised against using tests made by Cue Health .

Medications to prevent and treat Covid

In March, the F.D.A. approved a new medication for highly immunocompromised people, such as those receiving stem cell or organ transplants. The drug, Pemgarda, is a monoclonal antibody infusion that can be taken as a preventive measure, before people contract the virus.

People age 12 and older who have tested positive can take Paxlovid within five days of developing symptoms. The medication halts the virus from replicating in the body and lowers the risk of death for people who are more vulnerable to severe disease. There is no evidence that Paxlovid is less effective against the current leading variants than previous strains of the virus, experts said. Scientists are still debating whether Paxlovid can reduce the risk of developing long Covid.

There are two other antiviral treatments that doctors use much less frequently: remdesivir, or Veklury, which is given as an IV infusion to adults and children, and molnupiravir, known as Lagevrio, which is a pill that can be used to reduce the risk of severe disease in adults.

Doctors advise resting as much as possible while sick. If you’re up for it, take a lap around the block — “you should not be completely inactive,” Dr. Sax said — but don’t push yourself.

“Some people like to take long walks,” Dr. Smith said. “I just stay in bed and read a book. Basically, you just suffer through it.”

Dani Blum is a health reporter for The Times. More about Dani Blum