Importance
The prevention and treatment of traveler’s diarrhea (TD) is a common reason that patients consult their physician prior to foreign travel. TD can result in lost time and opportunity, as well as overseas medical encounters and hospitalization. to providers regarding the use of antibiotic and nonantibiotic therapies for the prevention and treatment of TD.
Prophylaxis
Dr. Neil Skolnik (left) and Dr. Aarisha Shrestha
The panel recommends that antimicrobial prophylaxis should not be used routinely in travelers, but it should be considered for travelers who are at high risk of health-related complications of TD (both strong recommendations, low/very low level of evidence [LOE]). High-risk individuals include those with a history of clinically significant long-term morbidity following an enteric infection or serious chronic illnesses that predisposes them for TD-related complications. Bismuth subsalicylate (BSS) may be considered for any traveler to prevent TD (3, strong recommendation, high LOE). Studies show that a lower dose of 1.05 g/day is preventive, although it is unclear whether it is as effective as higher doses of 2.1 g/day or 4.2 g/day. When prophylaxis is indicated, travelers should be prescribed rifaximin (strong recommendation, moderate LOE) based on susceptibility of most enteric pathogens and the drug’s extremely favorable safety profile. Fluoroquinolones (FQ) are no longer recommended for prophylaxis (strong recommendation, low/very low LOE) because of neurologic and musculoskeletal side effects that may outweigh benefits, as well as emerging resistance of enteric pathogens (70%-80% in Campylobacter spp. from Nepal and Thailand and 65% in Enterotoxigenic Escherichia coli [ETEC] and Enteroaggregative E. coli [EAEC] in India).
Treatment
The following treatment recommendations are based on the classification of TD using functional effects of severity; therefore, the panel made new definitions for TD severity. This is a change from previous definitions that utilized a traditional frequency-based algorithm in order to tailor therapy for the individual. Individuals can be prescribed antibiotics and antimotility agents to take with them during travel, along with advice regarding how to judge when to use each agent.
Mild: diarrhea that is tolerable, is not distressing, and does not interfere with planned activities.
Encourage supportive measures such as rehydration and nonantibiotic, antimotility drugs, such as loperamide or BSS (both strong recommendations, moderate LOE).
Moderate: diarrhea that is distressing or interferes with planned activities.
Antibiotics may be used (weak recommendation, moderate LOE) as early and effective treatment may mitigate the well-described chronic health consequences including irritable bowel syndrome. Three options exist. FQs may be used outside of Southeast and South Asia (strong recommendation, moderate LOE), but their potential for adverse effects and musculoskeletal consequences must be considered. Azithromycin may be used (strong recommendation, high LOE) because studies show no significant differences in efficacy between it and FQs, limited resistance to common TD pathogens (although concerns exist in Nepal), and good side effect profile. Another choice is rifaximin (weak recommendation, moderate LOE), although one should exercise caution for empirical therapy in regions in which being at high risk of invasive pathogens is anticipated.
Loperamide may be used as adjunctive therapy for moderate to severe TD (strong recommendation, high LOE) to add symptomatic relief with curative treatment or as monotherapy in moderate TD (strong recommendation, high LOE). This is specifically true in children aged 2-11 years, in whom loperamide is beneficial without causing severe side effects.