Polymicrobial aetiology of travellers' diarrhoea

Of 35 US Peace Corps volunteers in Thailand, 20 (57%) had a total of 30 episodes of diarrhoea during their first 6 weeks in the country. Enteric pathogens were associated with 90% of the episodes. A single pathogen was identified in 17 (57%) episodes, 2-4 pathogens were identified in 10 (33%) episodes, and there were 15 symptomless infections. Enterotoxigenic Escherichia coli (ETEC) was identified in 37% of these episodes, and various salmonella serotypes were isolated in 33%. Infections with 9 other enteric pathogens were also identified: Campylobacter jejuni (17%), Plesiomonas shigelloides (13%), Aeromonas hydrophila (10%), Blastocystis hominis (7%), Norwalk virus (7%), Vibrio parahaemolyticus (3%), non-O1 Vibrio cholerae (3%), Vibrio fluvialis (3%), and rotavirus (3%). In total, 56 enteric infections were documented in 35 volunteers.