The Centers for Disease Control and Prevention has identified ten cases of listeriosis across five states with the most recent on February 9th. Additional cases are anticipated based on the prolonged incubation period of listeriosis. Nine of the ten patients required hospitalization.  On June 20th, the FDA issued a warning letter to Abuelito Cheese Company confirming that previous inspections yielded environmental swabs positive for Listeria grayi and Listeria innocua.  The FDA concluded that while these two species of Listeria were present, the probability existed that cheese produced in the facility could be contaminated with Listeria monocytogenes.  As yet, the FDA and CDC have not concluded that cheese produced by the Company was the vehicle of infection and further investigations are in progress.  In the interim, the FDA is maintaining surveillance and has indicated that cheese produced in the plant may be responsible for the outbreak.

FDA has a zero tolerance for Listeria spp. and the presence of this Genus of pathogens in the environment of a plant, specifically in drains, suggest that intensive decontamination is required. This is especially the case for any plant producing ready-to-eat dairy or processed meat products.  In 2018, Listeria monocytogenes was isolated from a plant producing hard-cooked peeled eggs representing a potential health hazard.