By Donna Campisano, specialist, Communications, APHL

What do raw milk, raw pet food and a drug-laced chicken sandwich have in common?

They were all subjects of the “Contamination Chronicles” session at APHL’s 2025 Annual Conference held in Portland, Oregon, May 5-8.

Delivering disaster

Case: A resident of a rural county in Nebraska had presented at the emergency room with seizures, loss of consciousness and other medical problems, all occurring within minutes of eating a chicken sandwich brought to his home by a food delivery service.

Findings: A toxicology report from the hospital showed the patient tested positive for THC. When law enforcement got involved, the county’s sheriff asked for more comprehensive testing that would identify any number of toxins.

But there was a problem—the patient had eaten the sandwich in its entirety, leaving only pepper fragments to sample.

“If we had the sandwich, we could grind it up into a slurry and do an extraction on it,” said Erik Pearson of the Nebraska Department of Agriculture who was involved in the investigation. “But all we had were the plate and some pepper pieces. We didn’t find anything in the peppers, but we did do a rinse on the plate, which was found to have xylazine.”

Xylazine is a veterinary drug used for sedation and anesthesia and is sometimes added to drugs like fentanyl and heroin to enhance their effects, increase their weight and offer more street value, Pearson said.

End result: Lab results were handed over to law enforcement, but the laboratory was never asked to conduct any follow-up testing. It is not known how the patient fared or if any arrests were made.

“What kind of toxicology screening did they do at the hospital?” Pearson asked. “Would they even have thought about testing for xylazine? Do they have that capability? Did they catch a suspect? These are questions we’re still left with.”

Running a-fowl

Case:  A  4-year-old cat in Oregon was taken to the vet after she became lethargic and lost her appetite. Tests were run and the cat was put on steroids and antibiotics. But she didn’t get better. In fact, she got worse. Eventually, the cat became comatose and was humanely euthanized.

Findings: A rabies test was conducted on the cat postmortem, which turned up negative. But any feline tested for rabies in Oregon must also be tested for HPAI. HPAI testing is a new requirement in light of the current outbreak of the virus in dairy herds.

This test was positive.

To find the source of the infection, the cat’s owner was interviewed. The owner noted she sometimes took the cat on leash walks, but she hadn’t done so for the two weeks prior due to bad weather. And when she did walk the cat, she was sure to carefully monitor her and not allow her to stray.

The owner informed investigators that the cat was on a commercially prepared, turkey-based raw pet food; she had kept the food, suspecting it might be something that would need to be tested. Samples of the food were sent to the lab where genome sequencing genetically matched the strain of HPAI found in the raw food to the strain found in the cat’s brain.

“The HPAI strain found in the food is the same strain that’s going through dairy cattle,” said Jill DeSau, DVM, a veterinarian with the Oregon Department of Agriculture who worked on the case, “and there have been spillover events into turkey farms and turkey processors that are nearby.”

End result: The manufacturer of the pet food issued a voluntary recall of the product.

Raw deal

Case: The last case centered on a large, multi-county, multi-pathogen outbreak. All in all, 114 people were sickened during the outbreak, with one person dying.

Findings: As cases of illnesses began to be reported and an investigation was undertaken, a common denominator was identified: The consumption of raw milk and/or untreated water obtained from a local dairy.

 “We had a Campylobacter cluster, a Salmonella enterica cluster, an E. coli cluster and more,” said Kelly Oakeson, PhD, of the Utah Public Health Laboratory, who helped investigate the case. “There were even some patients infected with a combination of pathogens. We had a lot of cases, and whole genome sequencing showed they were related.”

Raw milk, which is legal to sell in some states with the appropriate permitting, carries its own health risks. Without pasteurization, raw milk can contain disease-causing germs. But the dairy itself was in violation of numerous health codes, from an abundance of flies near the milk to random piles of garbage.

Local authorities gave the dairy a cease-and-desist order to stop selling its milk and water, but investigators found that it was still supplying facilities with its products.

Oakeson said all this was occurring while the lab was conducting additional testing on samples. “But we couldn’t ever get culture confirmation of the PCR positives for the Campylobacter and E. coli because there was so much bacteria on the coliform plate that sequencing a sample to link it back to a patient strain was like finding a needle in a haystack,” he said.

The laboratory team used metagenomic sequencing on the samples and plotted out the different pathogens found in the raw milk. “There was definitely E. coli in there,” Oakeson noted. “There was Campylobacter. There was Giardia. And several other things. We were able to take these sequencing reads and align them with clinical cases so we could have a confirmation that the cases were linked to the dairy.”

End result: The outbreak was a challenging one to investigate.

“The same people operate various dairy farms, so we didn’t always know where the products were coming from,” Oakeson said. “And the metagenomic testing we did is not verified under any Food and Drug Administration or United States Department of Agriculture regulatory body, so it made it hard for us to use it as evidence in court proceedings.”

The post Contamination Chronicles: How Laboratory Scientists Cracked Three Unusual Food Safety Cases appeared first on APHL Blog.

Visit Original Post >>>