Environmental interventions for the prevention of travelers' diarrhea.

The diarrheal illnesses affecting travelers to areas with low standards of hygiene are due to exposure to microbial agents not in wide circulation in the travelers' home area. A major objective for the prevention of travelers' diarrhea should be to minimize exposure to these infectious agents. Studies of sporadic and epidemic travelers' diarrhea have shown that contaminated food and water are usually the most important vehicles for transmission of these agents. Travelers must know which foods and water sources to avoid and which they may reasonably be assured are safe. Also, methods for disinfecting potentially contaminated sources must be simple and practical. Acceptable methods for ensuring the safety of food and drink are amply documented in the literature. However, although the consumption of certain foods and beverages is clearly associated with an increased risk of developing travelers' diarrhea, in some retrospective studies adherence to strict dietary rules generally did not appear to diminish the incidence. Despite these findings, whose validity may have been weakened by study design flaws, careful attention to the preparation and choice of food and beverage is recommended for prevention of both diarrheal and nondiarrheal illnesses.