Traveler's guide to avoiding infectious diseases
Travelers' health; Infectious diseases and travelers
Different areas of the world have different diseases and different prevalence rates of diseases. Travelers going to foreign countries may encounter diseases to which they have no natural immunity and should take any possible precautions.
Malaria is caused by a parasite transmitted from one human to another via the bite of an infected Anopheles mosquito. The parasites migrate to the liver, mature and enter the bloodstream, where they rupture red blood cells. An infected pregnant woman can transmit malaria to her unborn child.
Information
You can stay healthy during travel by taking the right steps to protect yourself before you go. You can also do things to help prevent disease while you are traveling. Most infections you catch while traveling are minor. In rare cases, however, they can be severe, or even deadly.
Diseases vary in different places in the world. You will need to take different preventive steps, depending on where you are going. The following things should be considered:
- Insects and parasites
- Local climate
- Sanitation
The best public sources for up-to-date travel information are the:
- Centers for Disease Control and Prevention (CDC) --
www.cdc.gov/travel - World Health Organization (WHO) --
www.who.int/health-topics/travel-and-health#tab=tab_1
BEFORE TRAVEL
Talk to your health care provider or visit a travel clinic 4 to 6 weeks before you leave for your trip. You may need several vaccinations. Some of these need time to work.
You also may need to update your vaccinations. For example, you may need "booster" vaccines for:
COVID-19 - Diphtheria, tetanus, and pertussis (Tdap)
- Influenza (flu)
- Measles - mumps - rubella (MMR)
- Polio
You also may need vaccines for diseases that are not commonly found in North America. Examples of recommended vaccines include:
Certain countries have required vaccinations. You may need proof that you have had this vaccine in order to enter the country.
- Yellow fever vaccination is required to enter certain Sub-Saharan, Central African, and South American countries.
- Meningococcal vaccination is required to enter Saudi Arabia for the Hajj pilgrimage.
- For a complete list of country requirements, check the CDC or WHO websites.
People who may have different vaccine requirements include:
- Children
- Older people
- People with weakened immune systems or HIV
- People who expect to be in contact with certain animals
- Women who are pregnant or breastfeeding
Check with your provider or local travel clinic.
PREVENTING MALARIA
Malaria is a serious disease that spreads by the bite of certain mosquitoes, typically biting between dusk and dawn. It occurs mainly in tropical and subtropical climates. Malaria can cause high fevers, shaking chills, flu-like symptoms, and anemia. There are 4 types of malaria parasites.
If you are traveling to an area where malaria is common, you may need to take medicines that prevent the disease. These medicines are taken before you leave, during your travel, and for a short period after you return. How well the medicines work varies. Some strains of malaria are resistant to some preventive medicines. You should also take steps to prevent insect bites.
ZIKA VIRUS
Zika is a virus passed to humans by the bite of infected mosquitoes. Symptoms include fever, joint pain, rash, and red eyes (conjunctivitis). The mosquitoes that spread Zika are the same type that spread dengue fever and chikungunya virus. These mosquitoes usually feed during the day. No vaccine exists for preventing Zika.
There is believed to be a link between mothers with Zika infection and babies born with microcephaly and other birth defects. Zika can spread from a mother to her baby in the uterus (in utero) or at the time of birth. A man with Zika can spread the disease to his sex partners. There have been reports of Zika spreading through blood transfusion.
Before 2015, the virus was found mainly in Africa, Southeast Asia, and the Pacific Islands. It has now spread to many states and countries including:
- Brazil
- Caribbean Islands
- Central America
- Mexico
- North America
- South America
- Puerto Rico
The disease has been found in certain regions of the United States. For the most up-to-date information, please visit the Centers for Disease Control and Prevention's (CDC) website --
To prevent getting the Zika virus, take steps to avoid mosquito bites. Sexual transmission of the virus can be prevented by using condoms or not having sex with a person who is possibly infected.
PREVENTING INSECT BITES
To prevent against bites from mosquitoes and other insects:
- Wear insect repellent when you are outdoors, but use it safely. Conventional repellents include DEET and picaridin. Some biopesticide repellents are oil of lemon eucalyptus (OLE), PMD, and IR3535.
- You may also need to use a bed mosquito net while you sleep.
- Wear trousers and long-sleeved shirts, particularly at dusk.
- Sleep only in screened areas.
- Do not wear perfumes.
FOOD AND WATER SAFETY
You can get some types of infections by eating or drinking contaminated food or water. There is a high risk of infection from eating undercooked or raw foods.
Stay away from the following foods:
- Cooked food that has been allowed to cool (such as from street vendors)
- Fruit that has not been washed with clean water and then peeled
- Raw vegetables
- Salads
- Unpasteurized dairy foods, such as milk or cheese
Drinking untreated or contaminated water can lead to infection. Only drink the following liquids:
- Canned or unopened bottled beverages (water, juice, carbonated mineral water, soft drinks)
- Drinks made with boiled water, such as tea and coffee
Do not use ice in your drinks unless it is made from purified water. You can purify water by boiling it or by treating it with certain chemical kits or water filters.
OTHER STEPS TO PREVENT INFECTIOUS DISEASES
Clean your hands often. Use soap and water or an alcohol-based cleanser to help prevent infection.
Do not stand or swim in fresh-water rivers, streams, or lakes that have sewage or animal feces in them. This can lead to infection. Swimming in chlorinated pools is safe most of the time.
WHEN TO CONTACT A MEDICAL PROFESSIONAL
Diarrhea can sometimes be treated with rest and fluids. Your provider may give you an antibiotic to take on your trip in case you get sick with severe diarrhea while traveling.
Get medical care right away if:
- Diarrhea does not go away
- You develop a high fever or become dehydrated
Contact your provider when you return home if you were sick with a fever while traveling.
References
Beran J, Goad J. Routine travel vaccines: hepatitis A and B, typhoid. In: Keystone JS, Kozarsky PE, Connor BA, Nothdurft HD, Mendelson M, Leder, K, eds. Travel Medicine. 4th ed. Philadelphia, PA: Elsevier; 2019:chap 11.
Centers for Disease Control and Prevention website. Zika virus. For healthcare providers: clinical evaluation and disease.
Centers for Disease Control and Prevention website. Zika virus: transmission methods.
Chen LH. Approach to the patient before and after travel. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 265.
Christenson JC, John CC. Health advice for children travelling internationally. In: Kliegman RM, St. Geme JW, Blum NJ, Shah SS, Tasker RC, Wilson KM, eds. Nelson Textbook of Pediatrics. 21st ed. Philadelphia, PA: Elsevier; 2020:chap 200.
World Health Organization website. International Travel and Health 12 May 2021 - Country List.
Version Info
Last reviewed on: 11/19/2023
Reviewed by: Jacob Berman, MD, MPH, Clinical Assistant Professor of Medicine, Division of General Internal Medicine, University of Washington School of Medicine, Seattle, WA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
