The central Scotland Escherichia coli O157 : H7 outbreak: Risk factors forthe hemolytic uremic syndrome and death among hospitalized patients

Little is known about risk factors for complications of Escherichia coli O1 57:H7 infection in adults. The 1996 outbreak in central Scotland involved t he largest number of adult case patients in whom hemolytic uremic syndrome (HUS) developed and, ultimately, the largest number of deaths associated wi th E coli O157:H7 infection that has yet been recorded. We investigated ris k factors for HUS in a retrospective study of all hospitalized case patient s in this outbreak. Of 120 case patients, 34 had HUS develop, 28 of whom we re adults. Sixteen adults died. Significant risk factors for HUS were age < 15 years or >65 years (odds ratio [OR], 4.4; 95% confidence interval [CI], 1.3-14.4), hypochlorhydria (OR, 6.7; 95% CI, 1.9-24.0), and coincidental an tibiotics (OR, 4.7; 95% CI 1.4-16.5). Factors associated with HUS were as f ollows: white blood cell count > 20 X 10(9) cells/L (OR, 8.25; 95% CI, 1.1- 60.3), neutrophil count > 15 X 10(9) cells/L (OR, 8.5; 95% CI, 1.5-50.1), a nd serum albumin level <35 g/L (OR, 7.2; 95% CI 1.2-42.5) <less than or equ al to>3 days after symptom onset. Deaths were confined to case patients >65 years of age. Early identification of risk factors for HUS is vital and co uld select case patients for trials of preventive and treatment therapies.