Travelers' Diarrhea: New Guidelines for Prevention and Treatment

Travelers' Diarrhea: New Guidelines

Travelers' diarrhea is the most predictable travel-related illness and affects 30%-70% of international travelers, depending on destination, season of travel, and other factors.^[1] Although most cases of travelers' diarrhea are self-limited and mild to moderate in severity, diarrhea can limit a tourist's itinerary or business activities. Consequently, travelers, particularly in developing countries, are frequently prescribed an antibiotic to self-treat diarrhea, should it develop.

In recent years, research^[2,3,4,5] showing antibiotic-mediated disruption of the microbiome and subsequent colonization with resistant organisms has raised concerns about travelers as vehicles for spreading resistance globally as well as possible individual health consequences of acquisition of these resistant organisms.

The International Society of Travel Medicine convened a group of experts on travelers' diarrhea to review the available evidence and produce clinically relevant and useful recommendations on the management of travelers’ diarrhea.^[6] Each recommendation was graded according to its strength and the quality of supporting evidence. Clinicians can refer to the full guidelines for additional information on the recommendations and supporting evidence.

For the purpose of these recommendations, the expert panel used the following functional impact definitions to classify travelers' diarrhea:

Mild: diarrhea that is tolerable, not distressing, and does not interfere with planned activities
Moderate: diarrhea that is distressing or interferes with planned activities
Severe: diarrhea that is incapacitating or completely prevents planned activities; all dysentery (passage of grossly bloody stools) is considered severe
Persistent: diarrhea lasting 2 weeks or longer

New Recommendations

Prophylaxis for Travelers' Diarrhea

Antimicrobial prophylaxis should not be used routinely in travelers (strong recommendation, low/very low level of evidence).
Antimicrobial prophylaxis should be considered for travelers at high risk for health-related complications of travelers' diarrhea (strong recommendation, low/very low level of evidence).
Bismuth subsalicylate (BSS) may be considered for any traveler to prevent travelers' diarrhea (strong recommendation, high level of evidence). BSS has been studied using four divided doses of either 2.1 g/day or 4.2 g/day (with meals and at bedtime). A lower divided dose of 1.05 g/day has also been shown to be preventive, although it is unclear whether it is as effective as the higher doses.
When antimicrobial prophylaxis is indicated, rifaximin is recommended for all regions (strong recommendation, moderate level of evidence).
Fluoroquinolones are not recommended for prophylaxis of travelers' diarrhea (strong recommendation, low/very low level of evidence).

Therapy for Mild Travelers' Diarrhea

Antibiotic treatment is not recommended in patients with mild travelers' diarrhea (strong recommendation, moderate level of evidence).
Loperamide or BSS may be considered to treat mild travelers' diarrhea (strong recommendation, moderate level of evidence). The loperamide starting dose is 4 mg, followed by an additional 2 mg after each additional loose or liquid stool, up to 16 mg/day.