Submitted to: Proceedings of the International Conference on Emerging Infectious Diseases
Publication Type: Abstract only
Publication Acceptance Date: 7/11/2010
Publication Date: 7/11/2010
Citation: White, P., Cronquist, A., Heltzel, D., Douris, A., Pringle, J., Brown, S., Widenbach-Vigil, K., Manley, W., Cray, P.J., Levine, J. 2010. Utilization of USDA subtyping data as a surveillance and investigation tool: Salmonella Newport-MDR-Amp-C infections associated with ground beef. International Conference on Emerging Infectious Diseases. July 11-14, 2010. Atlanta, GA. Interpretive Summary:
Technical Abstract: Background: The USDA Food Safety and Inspection Service (FSIS), Centers for Disease Control and Prevention (CDC), and USDA Agricultural Research Service (ARS) have developed mechanisms to routinely compare molecular subtyping information on bacterial isolates of public health concern from PulseNet and VetNet databases. Using both databases, FSIS tracks the serotypes and pulsotypes associated with human illness recovered during microbiological testing of FSIS-regulated products. In July 2009 the FSIS Outbreak Section of Eastern Laboratory notified Agency epidemiologists of a cluster of S. Newport isolates. The laboratory identified ground beef isolates which were indistinguishable by PFGE pattern in both databases. Methods: Three states (CO, CA, WY) collected detailed epidemiological information on cases in the cluster. FSIS conducted traceback based on shopper card information to identify the source of the infections. ARS and CDC performed antimicrobial susceptibility profiles on case-patient and product isolates. Results: Thirty-nine clinical isolates from 11 states were identified. Of 22 CO case-patients, 20 consumed ground beef prior to illness onset; 90% (18/20) from a large supermarket chain. FSIS review of retail production records in CO and WY identified a supplier of ground beef consumed by cases. The establishment was the source of both the Pulsenet and VetNet ground beef isolates included in this PFGE cluster. Laboratory analysis confirmed both clinical and product isolates exhibited MDR-AmpC resistance. A recall was initiated for 825,000 pounds of ground beef products. The establishment implemented new pathogen control measures and an intensified Salmonella testing program of incoming source materials. FSIS continues to verify the establishment’s food safety systems and microbial interventions. Conclusions: Cross-utilization of PulseNet and VetNet data enhances surveillance and hypothesis generation during foodborne illness investigations. Detailed exposure information, adequate retail production records, as well as laboratory data led to the first recall of raw ground beef products due to multi-drug resistant S. Newport.