Multistate outbreaks require a rapid, coordinated response, requiring close collaboration, communication and sharing of information among local, state and federal partners to stop further illness. Investigating these outbreaks often reveals problems on the farm, in processing or in distribution, resulting in food adulteration. Lessons learned from these investigations can be instrumental in promoting preventive practices. Dynamic and modern factors in food production, human behavior, environmental changes and societal events result in unique infectious disease vehicles resulting in foodborne outbreaks. Advanced molecular detection methods including whole genome sequencing (WGS), have had a major impact on how outbreaks are investigated. Several significant outbreak investigations investigated in 2015 are worth noting.
METHODS:
FDA’s Coordinated Outbreak Response and Evaluation Network, (CORE) works with our federal, state and local public health, agriculture and regulatory partners to rapidly detect; respond and prevent foodborne disease.
RESULTS:
Our traditional means of outbreak investigation (relying on epidemiologic information from interviews and traceability information for points of service) have not always been able to identify a vehicle. New laboratory tools have yielded clues to identification of the causative vehicle. Challenges in vehicle identification include universal ingredients; exposure co-llinearities, multi-ingredient foods, cross contamination and multiple commodities at the point of service level; lack of lot-level traceability to retail locations; and a short shelf-life for produce items, resulting in failure to isolate an organism from the suspect food vehicle.
CONCLUSIONS:
WGS based real time surveillance for Listeria monocytogenes is increasingly used in near real time and investigative approaches are being adapted to incorporate this new technology. It was utilized by regulatory and public health agencies to rapidly identify LM contaminated pasteurized soft cheese products based on past inspection history findings which identified the organism in the food processing environment 5 years earlier. Novel LM outbreak investigations associated with caramel apples and ice cream, two different desert commodities, had never before been identified as a vehicle associated with Listeria. Cyclospora cayetanensisassociated with cilantro imported from Mexico demonstrated the critical nature of the Produce Safety Partnership, signed by FDA and Mexico officials in July 2014. Seven multistate outbreaks associated with a national restaurant retail chain in the span of a little over a year, attributed to non 0157 STEC organisms with new or very rare PFGE patterns, demonstrated the need for close collaboration with industry as key to our investigative efforts.