Epidemiology and Infection

Original Papers

A common, symptom-based case definition for gastroenteritis

S. E. MAJOWICZa1a2, G. HALLa3, E. SCALLANa4 c1, G. K. ADAKa5, C. GAUCIa6, T. F. JONESa7, S. O'BRIENa8, O. HENAOa4 and P. N. SOCKETTa1a2

for the International Collaboration on Enteric Disease ‘Burden of Illness’ Studies

a1 Foodborne, Waterborne, and Zoonotic Infections Division, Public Health Agency of Canada, Guelph and Ottawa, ON, Canada

a2 Department of Population Medicine, University of Guelph, Guelph, ON, Canada

a3 National Centre for Epidemiology and Population Health, Australian National University, Canberra, Australia

a4 Enteric Diseases Epidemiology Branch, Centers for Disease Control and Prevention, Atlanta, GA, USA

a5 Department of Gastrointestinal Infections, Health Protection Agency Centre for Infections, London, UK

a6 Disease Surveillance Unit, Department of Public Health, Msida, Malta

a7 Tennessee Department of Health, Nashville, TN, USA

a8 Division of Medicine & Neurosciences, University of Manchester School of Medicine, Manchester, UK

Abstract

National studies determining the burden of gastroenteritis have defined gastroenteritis by its clinical picture, using symptoms to classify cases and non-cases. The use of different case definitions has complicated inter-country comparisons. We selected four case definitions from the literature, applied these to population data from Australia, Canada, Ireland, Malta and the United States, and evaluated how the epidemiology of illness varied. Based on the results, we developed a standard case definition. The choice of case definition impacted on the observed incidence of gastroenteritis, with a 1·5–2·1 times difference between definitions in a given country. The proportion of cases with bloody diarrhoea, fever, and the proportion who sought medical care and submitted a stool sample also varied. The mean age of cases varied by <5 years under the four definitions. To ensure comparability of results between studies, we recommend a standard symptom-based case definition, and minimum set of results to be reported.

(Accepted July 11 2007)

(Online publication August 09 2007)

Correspondence:

c1 Author for correspondence: Dr E. Scallan, 1600 Clifton Road NE MSD63, Atlanta, GA 30333, USA. (Email: escallan@cdc.gov)

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