OBJECTIVETo study the distributional feature and clinical characteristics of infectious diarrhea caused by enterohemorrhagic Escherichia coli O157:H7, and to understand its pollution to the environment and the carrier status among livestock and poultry.

METHODSTo describing the incidence of diarrhea, to isolate and culture the pathogenic bacteria from samples of the patients with diarrhea and livestock or poultry with methods of microbiology, molecular biology and cytology, and then to determine the toxic factors.

RESULTSIn the first epidemic area in Suixian county, Henan province, 35 cases had been found during 17 March and 6 July with 91% of them above age of 60. Of them, 32 were complicated with acute renal failure, including 28 death (death rate: 87.50%). One hundred and seven strains of O157:H7 were isolated from the samples of livestock or poultry and 48 strains were isolated from patients. It was found that 67 strains having toxic gene through microbiological, molecular biological and cytological technologies. Five types of toxic factors were found.

CONCLUSIONThe main factor causing death was the complicated acute renal failure from diarrhea infected by E. coli O157:H7. The pathogen from livestock or poultry with high carrying rate might infect people through polluted water, food flies and close contacts. The outbreak of acute hemolytic uremic syndrome in Suixian county was caused by Enterohemorrhagic Escherichia coli O157:H7 infection.