Risk factors for the development of Escherichia coli O157:H7 associated with hemolytic uremic syndrome.

Verotoxin-producing Escherichia coli (VTEC) O157:H7 is a major cause of hemorrhagic colitis that is often associated with the development of hemolytic uremic syndrome (HUS). In July, 1996, a severe mass outbreak of VTEC O157 infection occurred in Sakai city, Osaka. The present study investigates the risk factors which may contribute to the development of HUS in the early stages of the VTEC O157 infection. There was no significant difference between HUS-developed and non-HUS-developed groups with respect to sex, age, rates of clinical manifestations, such as fever, abdominal pain and bloody stool, use of anti-diarrheal agents, anti-motility agents, and/or antibiotic agents, and serum sodium concentrations at the early stage of VTEC O157 infection. Thus, these factors did not appear to be risk factors associated with the development of HUS. In contrast, leukocyte counts and C-reactive protein levels in the early stage of VTEC O157 infection were significantly higher in the HUS-developed group (P < 0.001), suggesting that these are risk factors associated with the development of HUS.