Travelers’ diarrhea (TD) is a clinical syndrome resulting from microbial contamination of ingested food and water; it occurs during or shortly after travel, most commonly affecting persons traveling from an area of more highly developed hygiene and sanitation infrastructure to a less developed one. Thus, TD is defined more by circumstances of acquisition than by a specific microbial agent. In fact, there is considerable diversity in etiologic agents, which include bacteria, parasites, or viruses. A similar but less common syndrome is toxic gastroenteritis, caused by ingestion of pre-formed toxins. In this syndrome, vomiting may predominate, and symptoms usually resolve within 12-18 hours.
Travelers’ diarrhea occurs equally in males and females and is more common in young adults than in older people. In short-term travelers, bouts of TD do not appear to protect against future attacks, and more than one episode of TD may occur during a single trip.
For travelers to high-risk areas, several approaches may be recommended, which can minimize but never completely eliminate the risk of TD. These include
- instruction regarding food and beverage selection,
- use of agents other than antimicrobial drugs for prophylaxis, and
- use of prophylactic antibiotics.
Antibiotics are the principal element in the treatment of TD. Adjunctive agents used for symptomatic control may also be recommended.
As bacterial causes of TD far outnumber other microbial etiologies, empiric treatment with an antibiotic directed at enteric bacterial pathogens remains the best therapy for TD.
Fluid and electrolytes are lost in cases of TD, and replenishment is important, especially in young children or adults with chronic medical illness. In adult travelers who are otherwise healthy, severe dehydration resulting from TD is unusual unless vomiting is present. Nonetheless, replacement of fluid losses remains an important adjunct to other therapy. Travelers should remember to use only beverages that are sealed or carbonated. For more severe fluid loss, replacement is best accomplished with oral rehydration solutions.