Food Testing in Public Health Laboratories: Revolutionized by the Food Emergency Response Network (FERN)

By Frances Pouch Downes, Dr.P.H., Laboratory Director, Michigan Department of Community Health, and Jim Rudrik, PhD, Microbiology Section Manager, Michigan Department of Community Health

Food testing is core to foodborne disease outbreak detection and investigation. The methods used by many labs a decade ago were mostly determined by resource availability, and were largely culture-based. Quality assurance was minimal, and was mostly focused on quality control. There was a clear demarcation in funding between food testing performed for quality monitoring often performed in agriculture or commerce labs and outbreak investigations performed in PHLs. In some labs these functions were consolidated but the funding remained segregated.

With the creation of FERN new funding was available for equipment, reagents, supplies and additional personnel allowing PHLs to implement food testing methods that had not previously been feasible. Updated standard operating procedures which included validated probes and primers also enabled PHLs to offer non-culture based testing.

With the use of FERN funds, the Michigan Department of Community Health (MDCH) validated real time PCR protocols for Salmonella and Shiga toxin-producing E. coli (STEC) for routine use.  Implementation of PCR for STEC has led to the identification of  non-O157 stx-producing E. coli from outbreaks that would have been missed by conventional methods. Failure to identify these organisms delays outbreak recognition and can thwart outbreak investigation efforts ultimately resulting in illnesses that could have been prevented.

Through FERN, training is offered on PCR-based methods for use in food testing in PHLs. PCR-based methods decrease the turn-around time for results and allow PHLs to offer broader test panels. Network member labs also participate in foodborne pathogen test development and validation. This increases the expertise at participating sites and provides realistic evaluations of method performance in a range of testing venues.

Food testing quality assurance has been enhanced with FERN providing proficiency testing samples. PHLs can now validate their performance and generate accuracy data. By dissemination of standard methods used system-wide, results become comparable from laboratory to laboratory.  Food defense exercises allow real-time surge capacity testing of inter-agency abilities to collect, transport, test, perform sample trace back and above all communicate.

FERN promotes collaboration between food testing laboratories. In Michigan the funding was shared between Michigan Department of Agriculture and Rural Development (MDARD) and MDCH. Personnel from both labs were cross-training at both facilities with methods used at each laboratory. This cross-training increased the testing capacity and positioned the state to respond to large surges in testing due to an outbreak or other emergency.  The partnership between MDCH and MDARD has led to a sharing of expertise and technology; MDCH help develop molecular testing capabilities at MDARD and MDARD shared expertise in food testing gained from years of regulatory testing.

Even at peak funding, FERN was far from having full capability and capacity to detect and respond to foodborne disease outbreaks. With shrinking resources, its response capability has already been compromised.  Despite decreases in FERN funding, we have continued these collaborations.

If FERN funding continues to shrink, additional threats will further compromise the ability of the network to function as originally intended. Aging equipment will need to be updated or replaced. Test/reagents must be continually developed and distributed to detect newly emerging pathogens. And laboratories need to validate their performance on new methods and continued competence in established methods. Laboratory workforce maintenance requires not just continued funding for network capacity but also access to training. Robust quality assurance programs must be supported (e.g., exercises, proficiency testing challenges and validation studies) to maintain confidence and utility of the network.

FERN has been used repeatedly in the years since its inception. This laboratory resource is not sitting in a warehouse to be trotted out for some unknown future threat. New threats to our nation’s food supply are discovered on a regular basis. FERN has provided an avenue for PHLs to respond to these challenges, but funding cuts will adversely affect its ability to protect the American public.