Problems after arrival are especially important to prevent and avoid in international settings. Though many people are most concerned about infection when considering a trip overseas, heart disease is the most common cause of death among international travelers. Heart disease is the most common cause of death among nontravelers as well, suggesting that attention to health before leaving home is the best way to prevent illness while away.
Injuries are the most common cause of death among yiunger and middle-aged travelers. The most common are due to motor vehicle or water accidents. Common-sense measures can be taken to prevent many such injuries. For example, people uncomfortable with unfamiliar traffic patterns (such as driving on the left side of the road in England versus the right side in the United States) can take public transportation or hire drivers familiar with local roads and traffic laws. Travelers should avoid overcrowded taxis, ferries, or other transports and avoid nighttime driving and swimming in poorly lit areas. People should wear seat belts even as passengers and should use a helmet when cycling. Travelers should avoid motorcycles and mopeds and avoid riding on bus roofs or in open truck beds. Also, alcohol should never be consumed before driving or swimming, even where laws do not formally prohibit such actions or where laws that do exist are not enforced.
Many cities are unsafe after dark, and some are unsafe even during the day. A traveler should avoid walking alone on ill-lit or deserted streets in such cities, especially in countries where the traveler is obviously a stranger.
Traveler's diarrhea (see Gastroenteritis: Traveler's Diarrhea) is the most common infectious disease among international travelers.
The risk of traveler's diarrhea may be reduced by the following measures:
Taking certain antibiotics can also prevent traveler's diarrhea. However, such use has a risk of side effects and may increase the chances that bacteria will develop resistance to antibiotics. Thus, many doctors recommend preventive antibiotics only for people who have an immune deficiency disorder.
In most cases, traveler's diarrhea subsides by itself and requires only the steady intake of fluids to prevent dehydration. Ordinary clear liquids (without caffeine or alcohol) are adequate for most people. Young children and older people may benefit from powdered rehydration mixes or an oral rehydration solution. Other measures, though not always necessary, may be helpful.
People who have moderate to severe symptoms (3 or more unformed stools over 8 hours) should consider taking an antibiotic, especially if they have vomiting, fever, abdominal cramps, or blood in the stool. For most destinations, the appropriate antibiotic is ciprofloxacin or ofloxacin. Azithromycin is appropriate for Southeast Asia and the Indian subcontinent. People should contact their doctor for an antibiotic prescription before travel. If people are older than 6 years of age and have no bloody stools, fever, or abdominal pain, they can also be treated with the antidiarrheal drug loperamide (which is available without a prescription).
For older adults and young children, powdered rehydration mixes are available for travel. If these mixes are unavailable, rehydration solutions can be made with small amounts of salt, baking soda, and sugar or honey mixed in water. However, solutions should be prepared carefully because young children can become seriously ill or die if they drink much of a solution that has been incorrectly mixed (for example, if a rehydration mix has not been fully diluted).
Malaria (see Parasitic Infections: Malaria) is common throughout the tropics. Malaria is prevented by avoiding mosquito bites and taking an antimalarial drug. Mosquito bites are prevented by the following measures:
Insect repellants can also help prevent other mosquito-borne diseases such as dengue and yellow fever. Even with these measures, taking an antimalarial drug (such as mefloquine, chloroquine, or atovaquone/proguanil) is necessary.
Schistosomiasis is a common and potentially serious infection caused by a parasite that lives in fresh water in Africa, Southeast Asia, China, and eastern South America. Schistosomiasis can be prevented by avoiding freshwater activities in areas in which schistosomiasis is common (see Parasitic Infections: Schistosomiasis).
Lice and Scabies
Lice and scabies are common in crowded accommodations, underdeveloped areas, and places where hygiene measures are poor (see see Parasitic Skin Infections: Lice Infestation). They can be treated with permethrin, malathion, or lindane lotions. However, these lotions should not be used preventively.
Sexually Transmitted Infections
Sexually transmitted infections, including human immunodeficiency virus (HIV) infection, gonorrhea, syphilis, trichomoniasis, and hepatitis B, are more common in developing countries. All can be prevented through abstinence or with correct, consistent use of a condom (see Sexually Transmitted Diseases: How to Use a Condom). Because HIV and hepatitis B also are transmitted through blood and needles, an international traveler should not accept a blood transfusion without assurance that the blood has been tested for infection. Also, injections should be accepted only through one-time-only disposable needles.
Last full review/revision February 2009 by Christopher Sanford, MD, MPH, DTM&H