A comparative study of enterotoxigenic Escherichia coli, Shigella, Aeromonas, and Vibrio as etiologies of diarrhea in northeastern Thailand

The incidence of enterotoxigenic Escherichia coli (ETEC), Shigella, Aeromonas, and Vibrio was determined in patients with diarrhea seen at a hospital in northeastern Thailand, and compared with the incidence of these bacteria in household contacts and their neighbors. ETEC was identified in 17%, Shigella in 9%, Aeromonas in 9%, V. parahaemolyticus in 5%, and non-01 V. cholerae in 2% of 299 patients with diarrhea. These five species of bacteria were isolated more often from patients with diarrhea than persons without diarrhea (P < 0.001). ETEC was found more often in household contacts (22/141) and neighbors (18/147) of index cases than in persons living in homes not associated with ETEC infections (32/1,318; P < 0.001). While Shigella was isolated less often in family contacts (3/76) and neighbors (4/93) of patients with shigellosis, this enteric pathogen was also isolated more often from contacts than persons not associated with Shigella infection (13/1,437; P < 0.001). Both Aeromonas and non-01 V. cholerae can also be enteric pathogens; further efforts should be made to define the enteropathogenicity of these bacteria.