Epidemiology and Infection

Original Papers

Gastroenteritis and outbreaks

Attributing sporadic and outbreak-associated infections to sources: blending epidemiological data

D. COLEa1 c1, P. M. GRIFFINa1, K. E. FULLERTONa1, T. AYERSa2, K. SMITHa3, L. A. INGRAMa4, B. KISSLERa5 and R. M. HOEKSTRAa2

a1 Enteric Diseases Epidemiology Branch, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA

a2 Biostatistics and Information Management Office, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA

a3 Foodborne, Vectorborne, and Zoonotic Diseases Unit, Acute Disease Investigation and Control Section, Minnesota Department of Health, St Paul, MN, USA

a4 Communicable and Environmental Diseases and Emergency Preparedness, Tennessee Department of Health, Nashville, TN, USA

a5 Applied Epidemiology Division, Office of Public Health Science, Food Safety and Inspection Service, US Department of Agriculture, Atlanta, GA, USA

SUMMARY

Common sources of shiga toxin-producing Escherichia coli (STEC) O157 infection have been identified by investigating outbreaks and by case-control studies of sporadic infections. We conducted an analysis to attribute STEC O157 infections ascertained in 1996 and 1999 by the Foodborne Diseases Active Surveillance Network (FoodNet) to sources. Multivariable models from two case-control studies conducted in FoodNet and outbreak investigations that occurred during the study years were used to calculate the annual number of infections attributable to six sources. Using the results of the outbreak investigations alone, 27% and 15% of infections were attributed to a source in 1996 and 1999, respectively. Combining information from both data sources, 65% of infections in 1996 and 34% of infections in 1999 were attributed. The results suggest that methods to incorporate data from multiple surveillance systems and over several years are needed to improve estimation of the number of illnesses attributable to exposure sources.

(Received August 29 2012)

(Revised December 07 2012)

(Accepted March 20 2013)

(Online publication April 24 2013)

Key words

  • Epidemiology;
  • Escherichia coli ;
  • foodborne infections

Correspondence

c1 Author for correspondence: Dr D. Cole, DVM, PhD, Lead, Analytics Team, Enteric Diseases Epidemiology Branch, Division of Foodborne, Waterborne and Environmental Diseases, 1600 Clifton Rd, NE, MS C-09, Atlanta, GA 30333, USA. (Email: dcole@cdc.gov)

Metrics