Background: Traveler’s diarrhea (TD) can cause high morbidity among travelers. Multiplex methods have been developed recently for the molecular detection of causative agents of TD. However, these approaches are not yet sufficiently validated. The aim of this study was to test a multiplex-PCR approach in patients with TD and asymptomatic controls.
Materials/methods: A total of 91 travelers (61 TD cases, 30 asymptomatic controls) prospectively collected stool samples during travel and documented gastrointestinal symptoms. Samples were analysed using the BIOFIRE® Gastrointestinal (GI) Panel, which covers 13 enteric bacteria (e.g. diarrheagenic Escherichia coli), four protozoan parasites (Cryptosporidium spp., Cyclospora cayetanensis, Entamoeba histolytica, Giardia lamblia) and five viruses (adenovirus, astrovirus, norovirus, rotavirus, sapovirus).
Results: TD cases had more likely a positive test compared to controls (75 vs. 57%, p=0.07). The most common enteric pathogens were enteroaggregative E. coli (36/91, 40%), followed by enterotoxigenic E. coli (31/91, 34%) and enteropathogenic E. coli (EPEC, 29/91, 32%). The only pathogens significantly associated with TD were EPEC (p=0.01) and ETEC (p=0.047). Others were detected both in TD cases and asymptomatic controls without a clear association with disease. Protozoan parasites were not detected.
Conclusions: The results challenge the use of multiplex-approaches covering numerous enteric pathogens in the diagnostic workup of TD because only few (i.e. diarrheagenic E. coli) were related to symptoms of TD.