US food safety authorities have expanded a recall of cheese products linked to an ongoing multi-state outbreak of Listeria infections, warning consumers not to eat, sell, or serve the affected products.The US Food and Drug Administration (FDA) said Clover Hill Dairy, LLC of Mechanicsville, Maryland, expanded its recall on June 18 to include all cheese products manufactured at its facility due to possible contamination with Listeria monocytogenes. The agency's investigation remains ongoing.Cheese recall now includes all cheeses made at Clover Hill DairyThe expanded recall covers all cheese products manufactured at Clover Hill Dairy, including varieties of requeson, cuajada and hard cheeses. According to the FDA, some products may have been distributed under different brand names, including KESSO, QUESOS LA RICURA, IZALCO, DE MI PUEBLO and RIO LINDO.The recall expansion follows an earlier June 5 recall by Nelson & Isa Lacteos, LLC of Bay Shore, New York, which distributed Clover Hill Dairy products. The company recalled requeson cheese sold to retail locations in New York between May 15 and May 28, 2026.Investigation links outbreak to soft cheese productsThe FDA and the Centers for Disease Control and Prevention (CDC), working alongside state and local health authorities, are investigating what officials described as a multi-state, multi-year outbreak of Listeria monocytogenes infections. Investigators have linked the outbreak to requeson, a soft cheese similar to ricotta, manufactured by Clover Hill Dairy.As part of the investigation, federal and state officials collected product and environmental samples for testing. Six samples of requeson cheese tested positive for Listeria monocytogenes and matched the outbreak strain. One environmental sample collected from the facility also tested positive for the same strain.Maryland suspended facility's operating licenseThe Maryland Department of Health had previously issued a consumer advisory on June 3 regarding Clover Hill Dairy's requeson and soft ricotta cheese products. On May 30, state authorities suspended the facility's operating license because of public health concerns and have continued follow-up evaluations in cooperation with the company.The department later expanded its advisory on June 14 to include all cheese products manufactured at the facility due to the continuing risk of foodborne illness.States where recalled products were soldAccording to the FDA, recalled Clover Hill Dairy products were sold through the company's retail market, farmers markets and third-party distributors in:MarylandNew JerseyNew YorkNorth CarolinaVirginiaWashington, D.C.In addition, recalled Nelson & Isa Lacteos requeson products were sold at retail locations across New York between May 15 and May 28.What is Listeria and what are the symptoms?Listeriosis is a serious infection caused by the bacterium Listeria monocytogenes.Symptoms typically develop within two weeks of consuming contaminated food but can appear as early as the same day or as late as 10 weeks afterward.Mild symptoms may include:FeverMuscle achesNauseaFatigueVomitingDiarrheaMore severe illness may cause the following:HeadacheStiff neckConfusionLoss of balanceConvulsionsWho faces the highest risk?Health officials say pregnant women, newborns, adults aged 65 and older, and people with weakened immune systems face the greatest risk of severe illness.While pregnant women often experience only mild flu-like symptoms, infection can result in miscarriage, stillbirth, premature birth, or life-threatening infections in newborns.FDA urges consumers to discard recalled productsThe FDA is advising consumers to check refrigerators and freezers for recalled cheese products and either return them to the place of purchase or dispose of them immediately.Restaurants, retailers, and distributors that handled the recalled products are also being urged to thoroughly clean and sanitize surfaces, containers, and equipment that may have come into contact with the cheese to prevent cross-contamination.