Spatial and temporal dynamics of the prevalence of resistance genes and gastrointestinal pathogens in stool samples of German deployment returnees.

Background: The exploratory study assessed trends in the abundance of CTX-M-type extended spectrum beta-lactamase (ESBL) and vancomycin-resistance genes vanA and vanB in the stool samples of German soldiers and police officers returning from predominantly tropical deployments next to the common diarrheagenic Escherichia (E.) coli pathovars enteropathogenic Escherichia coli (EPEC), enterotoxigenic E. coli (ETEC) and enteroaggregative E. coli (EAEC)) as well as rarely imported Vibrio spp. between 2006 and 2024.

Methods: Surveillance was performed applying real-time polymerase chain reaction and results were stratified by World Health Organization region of deployment as well as by deployment period. For the latter, the study interval was divided into three pre-COVID-19-pandemic periods, the COVID-19-pandemic period and the post-COVID-19-pandemic period. Averaged prevalences were used as references.

Results: In stool samples of 1817 deployed German soldiers and 117 police officers, averaged prevalences were 47.9% and 24.8% for the ESBL-type beta-lactamase blaCTX-M, 30.2% and 14.5% for vanB, 9.0% and 17.9% for EPEC, 3.4% and 12.8% for ETEC, 4.0% and 3.4% for EAEC as well as 2.0% and 3.4% for Vibrio spp., respectively. While resistance genes peaked during early deployments, maximum prevalences for enteropathogens were seen later.

Conclusions: The assessment suggested time- and region-dependence of the assessed parameters.