Summary of FDA’s Strategy to Help Prevent Listeriosis Outbreaks Associated with Soft Fresh Queso Fresco-Type Cheeses
This fact sheet is intended to help Queso Fresco-type soft cheese manufacturing groups further their understanding of possible food safety risks that can occur in production and the resources available to help them consistently produce safe food.
What are soft Queso Fresco-type cheeses?
Soft Queso Fresco-type (QFT) cheeses are fresh, unripe cheeses that do not go through a significant aging process. These types of cheeses are white/off-white in color and very moist. They also have a low salt and acid content, which gives them a shorter shelf life compared to that of other aged cheeses. This also means soft QFT cheeses must always be refrigerated. Depending on the country of origin, some of the more popular fresh, soft QFT cheeses are labeled as either Latin-style or Mexican-style cheeses. Well-known examples of QFT cheeses include Oaxaca, Asadero, Queso Blanco, Queso Fresco, Requeson, and Panela, amongst others ,.
What are some concerns with soft Queso Fresco-type cheeses?
The pathogen of primary concern among soft QFT cheeses is Listeria monocytogenes (L. monocytogenes), a type of disease-causing bacteria that specifically causes the infection listeriosis. Outbreaks of listeriosis have been linked with soft QFT cheeses made from raw milk or those that contain ingredients that were contaminated somewhere during the cheese-making process. Historical outbreaks of listeriosis have been associated with QFT made from unpasteurized milk, but recent outbreaks have been caused by cheeses made from pasteurized milk that was contaminated during the cheese-making process. The soft QFT cheeses linked to past outbreaks were often manufactured by smaller-scale producers. These outbreaks have often affected a higher proportion of pregnant Hispanic women and their newborns. Listeriosis infections in pregnant women can result in serious illness, miscarriage, or even stillbirth. Older adults, newborns, and people with weakened immune systems are also at higher risk for developing serious symptoms associated with listeriosis. In addition to the risk of listeriosis linked to soft QFT cheese, the Centers for Disease Control and Prevention has reported multiple outbreaks linked to other pathogenic bacteria in these products, including Salmonella, Campylobacter jejuni, and Brucella ,.