Epidemiology and Infection

Research Article

Haemolytic anaemia after childhood Escherichia coli O 157.H7 infection: are females at increased risk?

P. C. Rowea1, W. Walopa1, H. Liora1 and A. M. Mackenziea1

a1 Departments of Pediatrics, Epidemiology and Community Medicine and Laboratory Medicine, University of Ottawa School of Medicine, Ottawa, Canada, and the National Laboratory for Enteric Pathogens, Laboratory Centre for Disease Control, Ottawa, Canada


We conducted a 4-year retrospective cohort study to better define the risk of haemolytic anaemia and haemolytic uraemic syndrome (HUS) in children following sporadic gastrointestinal infection with the O 157.H7 serotype of Escherichia coli. Of the 72 children infected with this organism, 9 (12·5%) developed haemolytic anaemia, 6 of whom had HUS. No child in a cohort of 72 age-matched controls with Campylobacter jejuni gastroenteritis developed haemolytic anaemia (P = 0·003). Females had a significantly greater risk of developing haemolytic anaemia after E. coli O 157.H7 infection than did males (8/29 females v. 1/43 males; P = 0·003). In a logistic regression model, female gender emerged as the only statistically significant risk factor for haemolytic anaemia (odds ratio 3·85; 95% confidence interval 1·24–12). These results are consistent with recent reports of a moderate increase in the risk of HUS for females.

(Accepted January 07 1991)