A large outbreak of Escherichia coli O157 infections via school lunches occ
urred at primary schools in 1996 in Sakai City, Japan. As many as 10000 pat
ients suffered from diarrhoea, haemorrhagic colitis and haemolytic uraemic
syndrome (HUS). Using data on 288 inpatient school children affected by thi
s outbreak, of whom 36 presented complete HUS and the remaining 252 tested
positive for E. coli O157 culture, we attempted to identify predictors for
the progression to HUS. Within the first 5 days of illness, clinical featur
es associated with inpatients who developed I-IUS compared with those witho
ut HUS included a C reactive protein (CRP) level higher than 1.2 mg/dl (OR
44.26; 95% CI 5.83-336.23), a white blood cell (WBC) count greater than 11.
0 x 10(9)/l (OR 5.03; 95 % CI 2.13-11.87) and a temperature higher than 38.
0 degrees C (OR 5.00; 95 % CI 2.25-11.08). It can be concluded that these t
hree factors are predictive factors for the development of HUS in patients
with E. coli O157 infection, and patients who have two or all of these fact
ors should be observed closely.