Bacterial causes of AIDS-associated diarrhea in Thailand

The incidence of bacterial diarrhea in AIDS patients has increased steadily and has led to enormous medical and public health problems. In this study, the clinical data together with 350 rectal swab samples each from AIDS patients with diarrhea (APD) and non-AIDS patients with diarrhea (NAPD), were collected and examined for bacterial enteropathogens at the Bamrasnaradura Infectious Diseases Hospital (BIDH), Nonthaburi, Thailand from May to December 1996. Patients were matched by age and sex. The majority of these patients were male (79%, 554/700), aged between 15 and 34 years (70.9%). The study found that the isolation rates of bacterial enteropathogens causing diarrhea in APD (18%, 62/350) were considerably lower than those in NAPD (43%, 152/350) (p<0.05). The infection rate with Salmonella group B (19.7%, 12/61) in APD was found to be significantly higher than that in NAPD (14.3%, 2/14) (p<0.05). Vibrio parahaemolyticus (53.3%, 81/152), Plesiomonas shigelloides (27%, 41/152), Aeromonas spp (19.1%, 29/152) and V. cholerae O1 (15.1%, 23/152), were more frequently detected in NAPD than in APD (p<0.05). Only nine Escherichia coli strains were isolated from APD, of which six were enteroinvasive E. coli, two enterotoxigenic E. coli and one enterohemorrhagic E. coli (non O157) possessing both vtl and vt2. No V. cholerae strains were detected in APD. The least effective antibiotics were ampicillin, tetracycline and cotrimoxazole. Antibiotic resistant patterns of the isolated organisms were similar from both groups. The results from this study might be useful in Thailand in the diagnosis and management of clinical cases of bacterial diarrhea, especially APD.