The Central Scotland Escherichia coli O157:H7 outbreak: risk factors for HUS and death
The Central Scotland Escherichia coli O157:H7 outbreak: risk factors for the hemolytic uremic syndrome and death among hospitalized patients. Dundas S, Todd WTA, Stewart AI, Murdoch PS, Chaudhuri AKR, Hutchison SJ. Clinical Infectious Diseases 2001;22:923-931.
Little is known about risk factors for complications of Escherichia coli O157:H7 infection in adults. The 1996 outbreak in Central Scotland involved the largest number of adult case patients in whom hemolytic uremic syndrome (HUS) developed and, ultimately, the largest number of deaths associated with E. coli O157:H7 infection that has yet been recorded. This paper examined risk factors for HUS in a retrospective study of all hospitalized case patients in this outbreak. Of 120 case patients, 34 developed HUS, 28 of whom were adults. HUS developed a median of seven days after the onset of gastrointestinal symptoms. Twelve of 28 adults and one of six children had neurological complications of HUS. Sixteen adults died; all were over 65 years of age. Eleven had complete HUS, three had an incomplete form of HUS and two had no evidence of microvascular complications. Seven of the 11 with complete HUS who died had neurological complications. Significant risk factors for HUS were age less than 15 years or greater than 65 years, low levels of gastric acid, fever and increased heart rate on admission, and coincidental antibiotics. Laboratory factors (assessed early in illness episode) associated with subsequent development of HUS were greater white blood cell and neutrophil count and lower serum albumin level. This study demonstrated that mortality associated with HUS in adults remains high even with intensive management. Early identification of risk factors for HUS is vital so that prevention and treatment may be employed. In addition, high-risk patients could be selected for clinical trials of Shiga toxin-binding agents to prevent HUS.