Deadly Multi-State Listeria Outbreak Traced to Clover Hill Dairy Soft Cheese, One Death Reported
核心洞察
A multi-year, multi-state Listeria monocytogenes outbreak linked to Clover Hill Dairy requesón/soft ricotta cheese has sickened eight people across Maryland, New York, and Virginia since 2023.
Seven of the eight patients required hospitalization, and one death has been reported, with whole genome sequencing confirming the outbreak strain in cheese samples.
Clover Hill Dairy issued a voluntary recall on June 3, 2026, and the Maryland Department of Health has suspended the facility's operating license.
A deadly outbreak of Listeria monocytogenes infections spanning three states and multiple years has been traced to requesón, a soft cheese similar to ricotta, manufactured by Clover Hill Dairy LLC (搜索) of Mechanicsville, Maryland. The outbreak has sickened eight people, resulted in seven hospitalizations, and caused one death, according to the Food and Drug Administration.
The outbreak, which began in 2023, has affected residents of Maryland, New York, and Virginia. Laboratory samples were collected from sick individuals from March 6, 2023, through May 9 of this year. Distribution of the implicated cheese has been confirmed in these three states, though officials note it may have been further distributed.
Investigation Timeline and Findings
The outbreak investigation gained momentum on May 13, 2026, when the Suffolk County Health Department in New York notified the New York State Department of Agriculture & Markets of two related Listeria illnesses within the same family. Both patients had purchased food from a local retailer in Brentwood, New York.
The following day, the New York State Department of Health confirmed that both patients had consumed requesón cheese purchased at that retailer. Investigators from the state agricultural department subsequently tested five cheese samples collected from the retailer. One sample of requesón that had been repacked by the retailer tested positive for Listeria monocytogenes, and whole genome sequencing (WGS) confirmed that the strain matched the strain causing illnesses in the two New York patients.
On May 27, the agriculture department conducted an inspection at the retailer's cheese distributor, which identified Clover Hill Dairy LLC (搜索) as the requesón cheese manufacturer. A sample collected from an unopened 18-pound sealed bucket of requesón manufactured by Clover Hill Dairy also tested positive for Listeria monocytogenes; WGS analysis for this sample is pending.
Recall and Regulatory Actions
On June 3, 2026, Clover Hill Dairy LLC (搜索) issued a voluntary recall of its requesón/soft ricotta products. The recalled products were sold directly from the company's retail market, at farmers markets, and through third-party distributors, including in New York and Virginia. Some varieties may feature jalapeño or other flavors, and products may be relabeled under a different brand name when distributed.
Due to the public health risk, the Maryland Department of Health has suspended Clover Hill Dairy LLC (搜索)'s operating license, issued a Consumer Advisory, and is conducting a follow-up evaluation in cooperation with the facility.
The FDA notes that it is in the early stages of this investigation, additional products may be impacted, and further testing by FDA and state partners is underway.
Consumer Guidance
Consumers are urged to check the manufacturer information on packages. The label should identify the Clover Hill Dairy manufacturer permit, or plant number, as "24-128." Anyone who has purchased products bearing this identifier should discard them immediately.
Of seven people interviewed during the investigation, five reported eating cheese before becoming sick, and two specifically reported eating requesón made by Clover Hill Dairy.
Clinical Considerations and At-Risk Populations
Listeria monocytogenes infections can be particularly dangerous for certain populations. Pregnant women, adults aged 65 and older, and individuals with weakened immune systems due to certain medical conditions or treatments face the highest risk of serious illness.
In pregnant women, Listeria infection can cause pregnancy loss, premature birth, or life-threatening infection in newborns, even when the mother experiences only mild, flu-like symptoms. Other individuals may experience headache, stiff neck, confusion, loss of balance, convulsions, fever, muscle aches, and tiredness.
Food contaminated with Listeria may not look, smell, or taste spoiled but can still cause serious and sometimes life-threatening infections. The incubation period can extend up to 70 days after exposure, meaning individuals who consumed the recalled cheese should monitor themselves for symptoms in the coming weeks.
Health officials recommend that anyone who has eaten the recalled cheese and developed symptoms of Listeria infection should seek medical treatment and inform their healthcare provider about the possible Listeria exposure. Specific laboratory tests are required to diagnose Listeria infections, which can mimic other illnesses.
The CDC advises that soft cheeses, even pasteurized ones, can be a riskier food choice for vulnerable populations. Consumers should clean refrigerators, containers, and surfaces that may have touched the recalled cheese, as Listeria can survive in the refrigerator and easily spread to other foods and surfaces.