Antibiotic Treatment of Travelers' Diarrhea Increases Acquisition of Resistant Bacteria

The increase and spread of multidrug-resistant organisms is perhaps the most consequential infectious diseases problem for the future. Overuse and injudicious use of antimicrobials contribute significantly to this problem. International travel is one way in which resistant bacterial strains are spread globally, but little attention has been paid to how initial colonization could be prevented during such travel.

Now, researchers have studied the effects of antibiotic self-administration for symptoms of travelers' diarrhea (TD) on the rate of stool colonization by extended-spectrum β-lactamase–producing Enterobacteriaceae (ESBL-PE) and carbapenemase-producing Enterobacteriaceae (CPE). Stool samples were collected and travel exposure–related histories taken before and after participants — individuals seeking predeparture advice at a travel clinic in Finland — journeyed outside of Scandinavia for >4 nights. Overall, 288 of the 430 participants developed TD; 52 of them used an antimicrobial for this condition (fluoroquinolones in 79%, macrolides in 13%).

Ninety participants (21%) became colonized with ESBL-PE, and none with CPE, during travel. Travel destination (particularly South and Southeast Asia), occurrence of TD, use of antibiotics for TD, and increased age of the traveler were independent risk factors for colonization; use of doxycycline for malaria prophylaxis had no effect. A traveler who went to South Asia, contracted TD, and took antibiotics for TD had an 80% chance of ESBL-PE colonization.