Ep. 225. Yasuda, Boeffard, Boyce: The Stop Alliance Mentorship Program: Lessons Learned and Collaborations Shared

Yeah, so first up in news, FDA held a much anticipated two-day public meeting on Listeria monocytogenes prevention in mid-August, bringing together regulators, academics, and industry experts to discuss ways to reduce listeriosis.

The meeting actually opened with a personal story from Stop Foodborne Illness constituent Tressa Bennett, who, along with her newborn twins, suffered a serious listeria infection in the late 1990s.

Tressa's story provided a powerful personal perspective at the science and policy focused meeting.

So although scientific understanding of listeria has advanced, speakers repeatedly came back to the importance of getting the fundamentals right.

That includes hygienic equipment and facility design, effective cleaning and sanitation, preventive maintenance, hygienic zoning, moisture and temperature control, and preventing post-lethality contamination.

Experts also stressed that sanitation procedures should be validated to demonstrate that they actually work rather than only verified to ensure that they're being carried out consistently.

Now, a major theme of FDA's Listeria meeting was environmental monitoring, and specifically the idea that a good environmental monitoring program should be designed to find Listeria rather than produce an artificially low positive rate.

Cornell University's Dr. Martin Weidman illustrated this point with research involving a small facility that collected around 300 environmental samples per year without detecting listeria.

But when researchers later sampled the same facility, they found three positives from only 50 samples.

Industry representatives also warned that punitive responses to positive findings could discourage facilities from sampling aggressively.

So instead, speakers advocated for a true seek-and-destroy approach using risk-based and event-triggered sampling, followed by root cause analysis to identify harborage sites and contamination pathways.

Another major discussion centered on whether dose response science should inform alternatives to zero tolerance approaches for listeria.

FDA's conservative dose response model from 2015 estimated that exposures to 10,000 CFU or less represented around 3.5% of U.S. listeriosis cases, despite accounting for more than 99.9% of contaminated food servings.

Rutgers University's Dr. Donald Schaffner pointed out that microbiological zero tolerance doesn't actually establish that zero organisms are present because whether contamination is detected depends on the intensity and sensitivity of sampling.

He argued that more intensive sampling plans that allow for very low-level positives might provide greater statistical protection, while also encouraging manufacturers to find and remediate contamination.

At the same time, experts cautioned that there is no universal safe threshold for listeria because susceptibility to listeriosis varies considerably among individuals.

The meeting also looked beyond food processing facilities to downstream controls.

For example, an international model presented at the meeting estimated that growth between retail and consumption could account for approximately 37% of predicted listeriosis cases in the EU, reinforcing the importance of sanitation, temperature control, date marking, employee hygiene, and cross-contamination prevention in retail environments.

Speakers also emphasized active managerial control and workforce education as important components of listeriosis prevention.

And finally, FDA researchers discussed how demographic changes could affect the future burden of listeriosis in the US.

So because older adults are particularly susceptible to severe listeriosis, the aging US population would be expected to increase disease incidence even if exposure remains unchanged.

Instead, listeriosis incidence has remained relatively stable over the past two decades.

So, based on this trend, experts estimated that listeria exposure may have declined by approximately 16%, suggesting that food safety interventions have helped offset demographic changes that otherwise could have increased listeriosis incidence.

I think that's really interesting statistically.

So interesting part of the meeting there.