Epidemiology and Infection

Epidemiologic profiling: evaluating foodborne outbreaks for which no pathogen was isolated by routine laboratory testing: United States, 1982–9

J. A.  HALL  a1 c1, J. S.  GOULDING  a2, N. H.  BEAN  a2, R. V.  TAUXE  a2 and C. W.  HEDBERG  a1
a1 Minnesota Department of Health, Minneapolis, MN, USA
a2 Centers for Disease Control and Prevention, Atlanta, GA, USA


The objective was to evaluate foodborne outbreaks of undetermined aetiology by comparing them to pathogen-specific epidemiologic profiles of laboratory-confirmed foodborne outbreaks. National foodborne outbreak data reported to CDC during 1982–9 were categorized by clinico-epidemiologic profiles based on incubation, duration, percent vomiting, fever and vomiting to fever ratio. From the pathogen-specific profiles, five syndromes were developed: a vomiting-toxin syndrome resembling Bacillus cereus and Staphylococcus aureus; a diarrhoea-toxin syndrome characteristic of Clostridium perfringens, a diarrhaeogenic Escherichia coli syndrome, a Norwalk-like virus syndrome, and a salmonella like syndrome. Of 712 outbreaks, 624 (87·6%) matched one of five syndromes; 340 (47·8%) matched the Norwalk-like syndrome and 83 (11·7%) matched the salmonella-like syndrome. After combining information on known pathogens and epidemiologic profiles, only 88 (12·4%) outbreaks remained unclassified. Norwalk-like virus outbreaks appear as common as salmonella-like outbreaks. We conclude that profiling can help classify outbreaks, guide investigations and direct laboratory testing to help detect new and emerging pathogens.

(Accepted June 29 2001)

c1 Author for correspondence: 12125 Technology Drive, MN002-0258, Eden Prairie, MN 55344 USA.