How FDA Investigators Pinpointed Cause of Illness Tied to Nutrition Shakes at Long-Term Care Facilities
By Erin Peabody, OO-Office of External Affairs
FDA food investigators Rohn Robertson and Hassan Ali got a call about an inspection earlier this year that would prove one of the most impactful of their careers.
A foodborne illness outbreak, caused by a particularly virulent strain of Listeria bacteria, was sickening older Americans living in nursing homes and other facilities across several states. Over 30 individuals had been hospitalized. Tragically, some had died.
The facts were chilling, Robertson recalled. The 23-year veteran FDA investigator — who works for the agency’s frontline Office of Inspections and Investigations (OII) — was looking forward to a much-anticipated ski trip with his daughter. But his experience conducting traceback investigations, sleuthing out the source of puzzling, and sometimes devastating, food-related outbreaks, was desperately needed.
Where to Begin?
FDA’s collaborators at the CDC knew the cluster was closely associated with long-term care facilities, but they hadn’t had much luck gathering specific exposure information. People living in long-term care facilities may suffer from a wide range of ailments that impact their ability to remember what they’ve eaten. So, FDA’s Coordinated Outbreak Response & Evaluation (CORE) team tried another tactic. They pored over purchase information from the long-term care facilities where they knew many of the recent outbreak victims lived. Two potential common food sources emerged: Lyons ReadyCare and Sysco Imperial frozen supplement shakes, both made by dairy product manufacturer Prairie Farms Dairy Inc. at its Fort Wayne, Indiana facility.
CORE leads agency efforts when it comes to responding to foodborne outbreaks. These foodborne illness experts, housed within the FDA’s Human Foods Program, work closely with OII frontline staff, like Robertson and Ali, who rush to facilities suspected of contamination to gather the data and evidence needed to confirm causes of illness and stop further harm to the public. Such rapid coordination was key to investigating the shakes that seemed to be making long-term care facility residents sick. CORE colleagues briefed Robertson and Ali, who then quickly made their way to Fort Wayne. The investigators worked feverishly to immerse themselves in the outbreak data CORE had supplied, as well as all relevant regulations, industry guidances, and best practices aimed at keeping U.S. dairy products safe.
Food Illness Detectives
While it’s the responsibility of industry to make sure its products are safe and produced in accordance with applicable requirements, it’s the FDA’s job—and specifically OII’s—to verify that firms are following the applicable FDA regulations, which are meant to protect the public. If industry is not in compliance, or consumers suddenly become ill because of a food they’ve consumed or used, the agency steps in to investigate what went wrong.
Bound by scientific integrity and transparency, the FDA is tasked with gathering clear evidence (for instance, a sample taken from a food production line that test positive for E. coli) to determine if the facility could be the source of contamination and then what action it should take to protect the public.
Environmental and product samples often form the basis of that evidence. But sampling, per exacting laboratory standards, takes time, something both Robertson and Ali knew they didn’t have a lot of in the current crisis. If the investigators were going to help solve the case and save lives—they would need to draw wisdom from past experiences, while also following a thorough sampling plan that left no stone unturned.
Gold Standard Science, With Common Sense
One of their priority areas, Robertson said, was “right under our feet.”
“Because they’re dark and damp, floor drains make a perfect breeding ground for Listeria bacteria.”
Thus, the OII team prioritized the drain and other areas from the main dairy processing room for swabbing and sampling and expedited those samples to FDA’s Seattle Human and Animal Food Laboratory, where they would undergo culturing and genetic analysis. In the meantime, Robertson and Ali continued to collect dozens of other environmental samples and conduct other aspects of the investigation, long into the night. This included briefing their CORE colleagues who remained poised to take the steps needed to protect the public.
A Match—With More Sleuth Work Needed
The samples from the floor drain came back positive for Listeria. Not only that, bioinformatic analysis of whole genome sequencing data indicated the isolates were closely genetically related to the strain that had caused illness and death in long-term care facility residents. But the investigators’ work wasn’t done.
“We still needed to correlate the evidence,” said Ali, “to show how it fit into the bigger picture of contamination.” To accomplish that, it was critical that Robertson and Ali had time, in addition to all the samples and photos being collected, and reports being prepared, to simply observe firm staff going about their typical daily activities.
It was through this strategy that the investigators spotted a faint cloud of condensation.
“That’s when we identified that the firm’s sanitation practices could be the root cause of the contamination,” said Robertson. Further investigation of Prairie Farms’ sanitation activities — in practice and on paper — revealed that a high-pressured hose used to clean the floor was potentially, and inadvertently, sending Listeria-contaminated water droplets from the drain back up into the air. From there, droplets could possibly mist down and compromise the liquid shake product. Robertson and Ali quickly communicated their discovery and other critical details to their CORE colleagues. Soon, recalls led to the removal of potentially tainted shakes from long-term care facilities and hospitals.
Critical Collaborations, Across Teams of Experts
“Just as our office name identifies, CORE is FDA’s coordinating office for multistate foodborne illness investigations,” said Dr. Stic Harris, CORE Director.
“It’s critical that we partner with outside agencies, such as CDC and our state partners, to gather information, follow the science, and develop actionable steps to protect public health.”
“In this instance, along with many others, our OII colleagues were invaluable in gathering investigational information that really put some of the puzzle pieces together to help solve this outbreak and prevent more people from getting sick.”
A Moment of Reflection
It was undeniable. Robertson and Ali — through their technical knowledge, swiftness, and grit—had saved lives. Because of their efforts, and that of their CORE colleagues, potentially harmful shakes were pulled from nursing homes, hospitals, and other institutions, stopping further illness and deaths from an outbreak that had stumped public health officials for far too long. The agency’s investigation also shined a light on the critical role that faulty industry sanitation practices can play in foodborne outbreaks.
But when asked what it was like to save lives and help solve a frightening public health crisis, neither FDA investigator seemed quite prepared to answer. Robertson choked up a little. “You know, we’re so busy on inspections, often working for days and weeks at a time, that we don’t get a chance to think about the broader impacts of the work. I don’t think Hassan and I even talked about it.”
“We haven’t,” replied Ali, who also seemed relieved to let his guard down for a moment. “Or for me to acknowledge Rohn and his help on this investigation. It was an honor to work with him and help protect some of the most vulnerable in our communities. I know I’ll never forget it.”