Prevalence of diarrheagenic Escherichia coli in Finns with or without diarrhea during a round-the-world trip

The incidence of diarrhea and the prevalence of bacterial enteropathogens, viruses, and parasites in feces of subjects with and without diarrhea were evaluated in 204 Finns traveling round the world (from Finland to China, Ma laysia, Australia, Fiji, Chile, and Brazil and back to Finland), Special em phasis was plated on the finding of diarrheagenic Escherichia coli (enterot oxigenic, enteropathogenic, Shiga toxin-producing, and enteroaggregative st rains) by PCR from growth on primary culture plates. From the PCR-positive samples, corresponding strains were isolated, confirmed as E. coli, and O s erotyped, Of all the subjects, 37% experienced a total of 90 episodes of di arrhea, No adenoviruses or rotaviruses were detected, and findings of paras ites were insignificant. In contrast, enteropathogenic bacteria were presen t in 62% of the 65 diarrheal and in 33% of the 127 nondiarrheal samples (P < 0.001); diarrheagenic E. coli strains were found in 35 and 26% of these, respectively (not statistically significant). As a single pathogen, E. coli was found in 20 and 24% of samples (not significant). Of all diarrheagenic E. call strains, enteropathogenic strains were the most commonly found ind ependently of the clinical picture of the subjects, whereas Salmonella ente rica as a single pathogen was the most common non-E. coli organism found in diarrheal samples. Multiple bacterial pathogens were found 10 times more c ommonly in diarrheal than in nondiarrheal samples (20 versus 2%; P < 0.001) .