Listeria Outbreak Linked to Clover Hill Dairy Cheese Kills One, Sickens 12 Across Four States

A deadly multistate Listeria monocytogenes outbreak linked to Clover Hill Dairy cheese has sickened 12 people across New York, Maryland, Virginia, and Illinois, resulting in 10 hospitalizations and one death in Maryland. Genetic testing matched the outbreak strain to six requesón cheese samples and one environmental sample from the dairy's facility, prompting a suspension of its operating license and an expanded recall of all Clover Hill cheese products. The outbreak's timeline spans from March 2023 to June 2026, indicating a long-term contamination issue.

Clover Hill Dairy Listeria outbreak

• ▪The Food and Drug Administration confirmed that the Listeria monocytogenes outbreak strain was detected in six samples of Clover Hill Dairy's requesón cheese and one environmental sample from the facility
• ▪The Maryland Department of Health suspended Clover Hill Dairy's operating license following the detection of the Listeria monocytogenes outbreak strain
• ▪The 12 confirmed Listeria cases are distributed across New York with five cases, Maryland with three cases, Virginia with three cases, and Illinois with one case
• ▪A multistate Listeria monocytogenes outbreak linked to Clover Hill Dairy cheese has sickened 12 people across four states, resulting in 10 hospitalizations and one death in Maryland

Three-year contamination timeline

• ▪The multi-year timeline suggests that the Listeria monocytogenes contamination was embedded in the Clover Hill Dairy manufacturing environment for a prolonged period before detection
• ▪Confirmed illness onset dates in the Clover Hill Dairy Listeria outbreak range from March 6, 2023, to June 2, 2026, indicating the contamination has persisted for over three years

High-risk patient populations

• ▪Listeria monocytogenes infections disproportionately cause severe illness, hospitalization, and death in pregnant people, newborns, adults aged 65 and older, and immunocompromised individuals
• ▪For pregnant individuals, a Listeria infection can lead to miscarriage, stillbirth, premature labor, or life-threatening infections in the newborn, even if the mother's symptoms are mild

Listeriosis symptoms

• ▪In high-risk individuals, invasive listeriosis can cause severe headache, stiff neck, confusion, loss of balance, and convulsions
• ▪Listeriosis symptoms can begin as early as the day of exposure or as late as 10 weeks afterward, presenting initially as fever, muscle aches, nausea, tiredness, vomiting, and diarrhea

Multi-state product recall

• ▪Nelson & Isa Lacteos, LLC issued a recall for one-pound plastic clamshell containers of requesón cheese sold at retail locations in New York from May 15 to May 28, 2026
• ▪Clover Hill Dairy cheeses were distributed in Maryland, New York, New Jersey, North Carolina, Virginia, and Washington, D.C., and may have been repackaged under brands like Kesso, Quesos La Ricura, Izalco, De Mi Pueblo, and Rio Lindo
• ▪Clover Hill Dairy expanded its voluntary recall on June 18, 2026, to include all of its cheese products, including Cuajada, Ricotta, Cheddar, Colby, Monterey Jack, and Cheddar Curds

Refrigerator cleaning protocol

• ▪The Centers for Disease Control and Prevention recommends a five-step refrigerator cleaning protocol, including washing shelves and drawers with hot soapy water and sanitizing with a dilute bleach solution
• ▪Because Listeria monocytogenes can grow at refrigerator temperatures, health officials advise that any surface or container that touched the recalled cheese must be thoroughly cleaned