GeoSentinel Analysis of Travelers' Diarrhea Antimicrobial Resistance Patterns

Key Points
Question
What are the antibiotic nonsusceptibility patterns in travelers’ diarrhea at cases presenting at GeoSentinel sites?

Findings
In this cross-sectional study of 859 cases, nonsusceptibility to fluoroquinolones was 75% for Campylobacter species, 32% for nontyphoidal Salmonella species, 22% for Shigella species, and 18% for diarrheagenic Escherichia coli species. Nonsusceptibility to macrolides was 12% for Campylobacter species, 16% for nontyphoidal Salmonella species, and 35% for Shigella species.

Meaning
These findings suggest that there are wide geographic differences in antibiotic nonsusceptibility patterns in travelers’ diarrhea; antimicrobial susceptibility from culture should be obtained when possible to inform strategies for self-treatment and clinician management of travelers’ diarrhea.

Abstract
Importance
Diarrheal disease causes substantial morbidity in international travelers. Knowledge of antibiotic resistance of causative pathogens helps guide empiric treatment decisions.

Objective
To characterize antimicrobial nonsusceptibility patterns of culture-confirmed Campylobacter species, nontyphoidal Salmonella (NTS) species, Shigella species, and diarrheagenic Escherichia coli isolated from international travelers with diarrhea identified by the GeoSentinel Surveillance Network.

Design, Setting, and Participants
This is a retrospective cross-sectional analysis of antimicrobial susceptibility data for 4 major pathogens causing travel-associated diarrhea, reported from April 14, 2015, to December 19, 2022, at 58 of 71 international GeoSentinel sites. Participants included a convenience sample of international travelers with acute diarrhea seen during or after travel presenting at the GeoSentinel sites.

Main Outcomes and Measures
The main outcomes were demographics, clinical characteristics, and antimicrobial susceptibility profiles of patients with culture-confirmed Campylobacter species, NTS species, Shigella species, and diarrheagenic E coli species. Routinely collected antimicrobial susceptibility data with intermediate susceptibility and resistant were defined as nonsusceptible. The antimicrobial susceptibility test results were described as numbers and percentages, and binomial 95% CIs were calculated for the proportions.

Results
Of 859 total cases, the median (IQR) age was 30 (23-43) years, and 440 travelers (51%) were male. Among Campylobacter isolates, nonsusceptibility to fluoroquinolones was found in 206 of 274 isolates (75%; 95% CI, 70%-80%), and nonsusceptibility to macrolides was found in 30 of 255 isolates (12%; 95% CI, 8%-16%) and was highest in travelers to South Central Asia (45 of 51 isolates; 88%; 95% CI, 76%-96%). Among NTS species, 96 of 302 isolates (32%; 95% CI, 27%-37%) were nonsusceptible to fluoroquinolones, 18 of 111 isolates (16%; 95% CI, 10%-24%) were nonsusceptible to macrolides, and 15 of 273 isolates (5%; 95% CI, 3%-9%) were nonsusceptible to third-generation cephalosporins. For Shigella species, 44 of 196 isolates (22%; 95% CI, 17%-29%) were nonsusceptible to fluoroquinolones, and 36 of 103 isolates (35%; 95% CI, 26%-45%) were nonsusceptible to macrolides. For E coli, fluoroquinolone nonsusceptibility was 18% (12 of 66 isolates; 95% CI, 10%-30%). Of note, 19 of 24 isolates (79%; 95% CI, 58%-93%) were nonsusceptible to fluoroquinolones among travelers to South Central Asia, and 29 of 37 isolates (78%; 95% CI, 62%-90%) were nonsusceptible to macrolides among travelers to South America.

Conclusions and Relevance
In this cross-sectional study of travelers’ diarrhea antimicrobial resistance patterns, there was marked variability of nonsusceptibility to 2 major classes of antibiotics commonly used for treating travelers’ diarrhea among global regions. Antimicrobial susceptibility from culture should be obtained when possible, including after pathogen detection by culture-independent methods. These findings may help inform strategies for self-treatment and clinician management of travelers’ diarrhea.