Traveler's diarrhea can be caused by bacteria, parasites, or viruses.
Organisms that cause the disorder are usually acquired from food or water, especially in developing countries where the water supply may be inadequately treated.
Nausea, vomiting, abdominal cramping, and diarrhea can occur with any degree of severity.
The diagnosis is usually based on the doctor's evaluation, but sometimes stool is tested for organisms.
Preventive measures include drinking only bottled carbonated beverages, avoiding uncooked vegetables or fruits, not using ice cubes, and using bottled water to brush teeth.
Treatment involves drinking plenty of safe fluids and sometimes taking antidiarrheal drugs or antibiotics.
(See also Gastroenteritis.)
Traveler’s diarrhea occurs when people are exposed to bacteria or, less commonly, viruses or parasites to which they have had little exposure and thus no immunity. The organisms are usually acquired from food or water (including water used to wash foods). Traveler’s diarrhea occurs mostly in developing countries where the water supply is inadequately treated. The bacteria Escherichia coli (E. coli) is the organism most likely to cause traveler’s diarrhea, particularly the types of E. coli that produce certain toxins and some viruses such as norovirus, which has been a particular problem on some cruise ships.
Travelers who avoid drinking local water may still become infected by brushing their teeth with an improperly rinsed toothbrush, drinking bottled drinks with ice made from local water, or eating food that is improperly handled or washed with local water.
The following symptoms of traveler's diarrhea can occur in any combination and with any degree of severity:
These symptoms begin 12 to 72 hours after ingesting contaminated food or water. Vomiting, headache, and muscle pain are particularly common in infections caused by norovirus. Most cases are mild and disappear without treatment within 3 to 5 days.
Travelers should eat only in restaurants with a reputation for safety and should not consume any food or beverages from street vendors. Cooked foods that are still hot when served are generally safe. Salads containing uncooked vegetables or fruit and salsa left on the table in open containers should be avoided. Any fruit should be peeled by the traveler. Travelers should drink only bottled carbonated beverages or beverages made with water that has been boiled. Even ice cubes should be made with water that has been boiled. Buffets and fast food restaurants pose an increased risk of infection.
Preventive antibiotics are recommended only for people who are particularly susceptible to the consequences of traveler’s diarrhea, such as those whose immune system is impaired. The antibiotics most commonly recommended are ciprofloxacin and azithromycin.
When symptoms occur, treatment includes drinking plenty of fluids and taking drugs that stop diarrhea such as loperamide. These drugs cannot be given to people who have a fever or bloody stools or to children under 2 years of age.
If diarrhea is more severe (3 or more loose stools over 8 hours), antibiotics are usually recommended (for adults, ciprofloxacin, levofloxacin, azithromycin, or rifaximin and, for children, azithromycin). Antibiotics are not given if a virus is the cause. Antiparasitic drugs are given if a parasite is identified in the stool.
Travelers are encouraged to seek medical care if they develop fever or blood in the stool.