Traveler's guide to avoiding infectious diseases

Travel can expose you to infections that are uncommon where you live. The risk depends on your destination, season, activities, accommodation, trip length, and health. Visiting friends and relatives can carry risks too, even if you previously lived at the destination.

This guide is not a diagnosis or a guarantee that infection can be prevented. It is a way to plan for risks you may meet through food, water, insects, animals, close contact, sex, freshwater, or medical care.

Ideally, arrange a pre-travel health appointment at least a month before departure. Some vaccines need time or more than one dose to provide protection. If you are leaving sooner, an appointment can still be useful.

Pregnancy, immune system conditions, long-term illnesses, and certain medicines can affect which vaccines or preventive medicines are suitable. A clinician or pharmacist can review these issues with you.

Infection prevention during travel uses several layers. No single step covers every infection.

Vaccines train your immune system to recognize particular germs. Before travel, check that routine vaccines are current. Your destination or planned activities may also lead a clinician to recommend travel vaccines. Some countries require proof of a specific vaccination for certain travelers.

Medicines can prevent some infections. For example, prescription antimalarial medicines may be advised for particular destinations. The choice is based on the exact itinerary, local malaria patterns, your health, and possible medicine interactions. Some must be started before arrival and continued after leaving.

Physical barriers reduce contact with insects. Use an insect repellent registered by the relevant national authority and follow its label. Long sleeves, long trousers, screened rooms, and bed nets can add protection. Permethrin-treated clothing or equipment may help, but permethrin products intended for fabric should not be placed directly on skin.

Food and water precautions lower the risk of swallowing harmful germs. Food that is thoroughly cooked and served hot is generally safer. Choose water from a reliable treated source or a sealed container. If local water safety is uncertain, remember that ice, drinks, toothbrushing, and food preparation may also involve that water.

Handwashing with soap and water is especially important before eating and after using the toilet. When soap and water are unavailable, an alcohol-based hand sanitizer can help, although it does not remove every type of germ.

Travel-related infections range from mild illnesses to conditions needing hospital care. Prevention can also protect people around you when you return, particularly infants, older adults, pregnant people, and people with weakened immune systems.

Your activities often matter as much as the country. Risk may increase with rural travel, camping, cave visits, healthcare work, contact with animals, swimming in freshwater, crowded events, or extended stays.

Some infections do not cause problems until after you return. Telling a clinician where you traveled, when you were there, and what you did can help them choose appropriate tests. Include stopovers and side trips, not only the main destination.

Travel insurance also has a health role. Check whether it covers medical care and evacuation, especially for remote travel. Know how to reach local emergency services and your insurer before you need them.

Unsafe food or water can transmit traveler’s diarrhea, hepatitis A, typhoid fever, and other intestinal infections. Raw or undercooked meat, seafood, eggs, and unpasteurized dairy products may carry additional germs.

Mosquitoes can spread malaria, dengue, yellow fever, Zika, chikungunya, and Japanese encephalitis in certain regions. Ticks, flies, and other biting insects also transmit infections. Repellent remains important even if you have received recommended vaccines or take malaria medicine.

Crowded transport, events, and shared indoor spaces can make respiratory infections easier to spread. These include influenza, COVID-19, measles, and tuberculosis. Staying away from others when ill, improving ventilation when possible, and using a well-fitting mask in higher-risk settings can reduce exposure.

Animal bites and scratches can transmit rabies in countries where it occurs. Dogs are a major source worldwide, but bats, monkeys, cats, and other mammals can also carry it. Avoid feeding or touching animals, including animals that appear healthy.

Freshwater in some regions can contain parasites that cause schistosomiasis. Sexual contact may transmit HIV, hepatitis B, syphilis, gonorrhea, and other sexually transmitted infections. Unsterile needles used for medical procedures, injections, tattoos, or piercings can transmit blood-borne infections.

These are possible travel-related conditions, not symptoms of “travel” itself. Your personal risk cannot be determined from a country name alone.

Before departure, make a written itinerary with dates, destinations, accommodation, activities, and rural or urban stops. Take it to a travel health appointment along with your vaccination record and medicine list.

Ask:

• Which routine and travel vaccines apply to this itinerary?
• Is malaria medicine recommended for any part of the trip?
• Are there entry requirements or vaccination certificates?
• What should I do if I am bitten or scratched by an animal?
• Which medical services are available at the destination?

Pack enough regular medicine for the trip, allowing for delays when permitted. Keep medicines in labeled packaging and check destination rules for controlled or restricted drugs. Consider carrying oral rehydration supplies, basic wound-care items, repellent, and condoms.

During travel, use recommended malaria medicine exactly as prescribed. Choose safer food and water, wash your hands, prevent insect bites, avoid unfamiliar animals, and use barriers such as condoms during sex. Do not share needles or equipment that can break the skin.

After travel, no general infection test is needed for most people who remain well. Testing may be advised after a specific exposure, prolonged high-risk travel, or work such as healthcare in a setting with tuberculosis exposure. Keep your itinerary and health records in case symptoms develop later.

Arrange routine medical follow-up for symptoms that are not severe but continue, such as persistent diarrhea, cough, rash, or unexplained fatigue. Tell the clinician about your travel.

Seek prompt medical care for fever during or after travel in a malaria-risk area. Mention the malaria exposure immediately, even if the trip was months ago. Prompt care is also important after a possible rabies exposure, severe or bloody diarrhea, jaundice, repeated vomiting, or worsening illness.

Call emergency services for trouble breathing, a seizure, fainting, new confusion, or signs of severe dehydration.

Do I need vaccines for every international trip?

Not necessarily. Recommendations are based on your destination, activities, health, vaccination history, and local outbreaks. Routine vaccines are important for domestic travel as well.

Is bottled water always safe?

An intact factory seal offers some reassurance, but bottled water quality is not identical everywhere. Where water safety is uncertain, use a reliable treated source and avoid ice made from untreated water.

Can I stop malaria medicine when I leave the risk area?

Not unless that matches the instructions for your specific medicine. Many antimalarial medicines must continue after departure. Follow the prescribed schedule.

Should I have tests when I return?

Usually not if you feel well and had no specific exposure. A clinician may suggest testing after certain activities, occupational exposures, long stays, or symptoms. There is no single test that checks for every travel-related infection.

What should I do after an animal bite or scratch?

Wash the area promptly and thoroughly with soap and running water. Seek urgent medical advice about rabies prevention, even if the wound is small or you received rabies vaccine before travel.