Travelers' diarrhea: an overview

The diarrhea of travelers is a syndrome and not a disease; its history is reviewed here. Dysentery is caused by agents that damage the epithelium of the intestinal tract; diarrhea results from the response of intact intestinal cells to toxins that stimulate enzymatic processes to release liquid and ions. Toxigenic Escherichia coli, the most frequent pathogen in diarrhea, produces a recognizable, benign syndrome; however, other agents of disease, including viruses, bacteria, and protozoa, are responsible for a significant proportion of cases of diarrhea. Hygienic precautions are generally advised, despite the lack of evidence supporting their efficacy. Antibiotic prophylaxis is effective in reducing the incidence of diarrhea caused by E. coli but may not be desirable because of toxicity and the possibility of complicating the diagnostic process. Diagnosis requires better laboratory methods than are usually available but can be made with limited accuracy by a clinician acquainted with the various manifestations of potential causes. Treatment after diarrhea has started should be limited to fluid and ion replacement, with the possible addition of drugs that reduce intestinal motility, although some advocate the use of antibiotics at this time. The number of people traveling, especially to developing countries, continues to increase. This trend would expand enormously if the fear of diarrhea were removed.