Additional cases have been confirmed as the listeria infection outbreak caused by soft cheese continues.
As of June 9, the outbreak at Clover Hill Dairy LLC in Mechanicsville, Maryland has resulted in nine cases. According to the Food and Drug Administration (FDA), eight of the patients required hospitalization and one died.
Samples from sick people were collected from March 6, 2023, to May 9, 2026. Five of the seven people interviewed reported eating cheese before becoming sick. Two people reported requests for meals from Clover Hill Dairy.
The dairy has recalled some of the requested cheese. The dairy company has since recalled all requests. Additionally, Bay Shore, New York-based Nelson & Isa Lacteos LLC recalled Riqueson cheese produced by Clover Hill Dairy. Nelson & Isa Lacteos LLC has repackaged the cheese and is unlabeled.
Clover Hill Dairy products are sold directly through Maryland retail markets, farmers markets, and third-party distributors, including in New York and Virginia. The sick people live in Maryland, New York and Virginia.
On May 13, the Suffolk County Health Department notified the New York State Department of Agriculture and Markets of two related Listeria monocytogenes illnesses in the same family that purchased food from a local retail store in Brentwood, New York. The next day, the New York State Department of Health confirmed that both cases consumed Requestson cheese purchased from the retailer.
Investigators tested five cheese samples collected from retail stores. One of the requested samples repackaged by the retailer tested positive for Listeria monocytogenes. Whole genome sequencing (WGS) We confirmed that the Listeria strain found in the requested cheese matched the Listeria strain causing illness in two New York cases who reported purchasing cheese from this retailer.
On May 27, the New York Department of Agriculture investigated the retailer’s cheese distributor and identified Clover Hill Dairy LLC, located in Mechanicsville, Maryland, as the requesting cheese manufacturer. Samples collected from unopened 18-pound sealed buckets manufactured by Clover Hill also tested positive for Listeria monocytogenes. Whole genome sequencing is pending.
The Maryland Department of Health suspended Clover Hill Dairy LLC’s operating license and issued the following orders: consumer advisoryWe are conducting follow-up evaluations in cooperation with the facility.
About listeria infection
Food contaminated with Listeria monocytogenes may not look, smell or taste spoiled, but it can still cause serious and sometimes life-threatening infections. Anyone who develops symptoms of Listeria infection after eating the cheese involved should seek medical attention and tell their doctor about possible Listeria exposure.
Additionally, people who have eaten the cheese involved should monitor themselves for symptoms over the next few weeks, as it can take up to 70 days after exposure to listeria for listeriosis symptoms to appear.
Symptoms of listeria infection include vomiting, nausea, persistent fever, muscle pain, severe headache, and neck stiffness. Specific laboratory tests are needed to diagnose listeria infection, which can mimic other illnesses.
People like pregnant women, the elderly, children, and cancer patients with weakened immune systems are particularly at risk for serious illness, life-threatening infections, other complications, and death. Infected pregnant women may experience only mild, flu-like symptoms, but the infection can cause premature delivery, neonatal infection, and even stillbirth.
