The 130th Annual Meeting of APHA

Abstract #47602

Laurence Burnsed, MPH¹, Lauri Smithee, MES, MS¹, Mike McDermott, BS², and Mike Crutcher, MD, MPH¹. (1) Communicable Disease Division, Oklahoma State Dept of Health, 1000 NE 10th St, Oklahoma City, OK 73117-1299, 405.271.4060, Laurence@health.state.ok.us, (2) Public Health Laboratory, Oklahoma State Dept of Health, 1000 NE 10th St, Oklahoma City, OK 73117-1299

Background: On July 27, 2001, the Public Health Laboratory reported 4 Salmonella enteritidis (SE) isolates that were indistinguishable by pulsed-field gel electrophoresis (PFGE) and distinct from other patterns identified in Oklahoma. We initiated an investigation to determine the source. Methods: We conducted a matched case-control study, matching 1 to 2 acquaintance or neighborhood controls per case by age, gender, and area of residence. Participants were interviewed by standard questionnaire regarding food histories and other exposures. Disease surveillance and environmental inspections were conducted. Results: We identified 51 cases (36 confirmed and 15 probable) with onsets ranging from July 1 – August 11. All 36 isolates tested by PFGE were indistinguishable. A total of 34 cases and 49 controls participated in the study. Consumption of meat items prepared by barbecue stand A was the only exposure significantly associated with illness (matched odds ratio 41.1, 95% confidence interval 7.12, ¥). Environmental inspections found cross-contamination and holding deficiencies. Salmonella isolates from cooked beef brisket and a hot link holding pan were indistinguishable from human isolates. The restaurant was closed on August 8 and no cases occurred after this date. Conclusion: Improper food handling practices resulted in a prolonged restaurant-associated salmonellosis outbreak. Routine surveillance had not identified an increase of SE above endemic levels. However, PFGE typing identified a subset of SE isolates that were indistinguishable. This investigation supports Centers for Disease Control and Prevention recommendations for routine PFGE typing of all Salmonella isolates.

Learning Objectives: At the conclusion of this session, the participant will be able to

• assess the role of PFGE in detecting outbreaks of Salmonellosis within endemic levels of disease; and
• evaluate the routine use of PFGE to type enteric organisms.

Keywords: Epidemiology, Outbreaks

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.