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Travelers' diarrhea: Microbiology, epidemiology, and prevention

Christine A Wanke, MD
Section Editor
Stephen B Calderwood, MD
Deputy Editor
Allyson Bloom, MD


Travelers' diarrhea is the most common illness in persons traveling from resource-rich to resource-limited regions of the world [1]. The fear of developing diarrhea while traveling is common among such travelers. This concern is realistic; 40 to 60 percent of travelers to these countries may develop diarrhea. Episodes of travelers' diarrhea are nearly always benign and self-limited, but the dehydration that can complicate an episode may be severe and pose a greater health hazard than the illness itself. Nevertheless, it is possible to educate a traveler to manage a diarrheal episode without compromising either their trip or their health.

The microbiology, epidemiology, and prevention of travelers' diarrhea are discussed here. The clinical manifestations, diagnosis, and treatment of travelers' diarrhea are discussed elsewhere. (See "Travelers' diarrhea: Clinical manifestations, diagnosis, and treatment".)


Travelers' diarrhea refers to diarrhea that develops during or within 10 days of returning from travel to resource-limited countries or regions. For epidemiological purposes, it is frequently categorized into three forms: classic, moderate, and mild. These forms of travelers' diarrhea are defined as follows [2]:

Classic — passage of three or more unformed stools in a 24 hour period plus at least one of these other symptoms: nausea, vomiting, abdominal pain or cramps, fever, blood in stools

Moderate — passage of one or two unformed stools in 24 hours plus at least one of the above symptoms or more than two unformed stools in 24 hours without other symptoms


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Literature review current through: Sep 2016. | This topic last updated: Nov 16, 2015.
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