Travelers' diarrhea

Abstract

Diarrhea is the most common health problem of travelers to tropical destinations, affecting up to over 50%, with however considerable regional and seasonal variation. Orally acquired bacterial pathogens, particularly enterotoxigenic Escherichia coli, are the most frequent etiology of travelers' diarrhea occurring during the first three weeks of travel. Protozoal infections, e.g. giardia and Entamoeba histolytica, are more often the cause of diarrhea and prolonged problems of intestinal motility of the returning traveler--as are postinfectious irritable bowel syndromes. Prevention seems theoretically simple by avoiding any potentially contaminated food and drinks, but the principle of 'cook it, boil it, peel it, or avoid it is obviously a goal difficult to achieve. Several antibiotics have shown to be able to prevent diarrhea for a short period of time, but the potential of adverse effects and selection of resistant pathogens calls for a restrictive use for short trips of particularly vulnerable subjects only. The use of probiotics--e.g. Saccharomyces boulardi, Streptococcus faecium--gave conflicting results--both in prevention and treatment. The basics of treatment is appropriate fluid replacement--mostly by the oral route. Although this measure can safely bridge the time until spontaneous remission, it fails to reduce the duration of illness. Appropriate antibiotics are fairly effective to reduce the duration of travelers' diarrhea, especially if combined with loperamid. The administration of the later is contraindicated in small children. The most commonly used and well documented antibiotics belong to the fluoroquinolones. Alternatives for pediatric use are azithromycin and cotrimoxazole. Considering the mostly short duration of travelers' diarrhea the administration of antibiotics can be limited to cases of acute febrile dysentery and violent diarrhea when rapid relief is essential. In cases of febrile diarrhea malaria must be considered if the patient has been exposed to the risk of transmission.