On Friday the CDC reported at least seven people have been sickened, and one died after eating "Hispanic-style cheese."
The CDC says the outbreak has affected people only of Hispanic descent and living in California or Maryland.
Three babies were among those infected with listeria, while the other five were adults, including two women who had recently given birth.
The illnesses date back to between August 1 and November 27, 2013.
CNN reports, earlier this month, health inspectors in Virginia found listeria monocytogenes bacteria in a sample of Cuajada en Terron, or fresh cheese curd, on sale in clear, unlabeled plastic bags at a Mega Mart in Manassas. This was traced to Roos Foods, a company based in Kenton, Delaware. Virginia authorities said at that time there were no known sicknesses in the state tied to that cheese.
A few days later, Maryland authorities' tests of pre-packaged cheese products produced by Roos Foods also came back positive for listeria. That state's health and mental hygiene department warned people not to buy or consume any products from that company sold under brand names Santa Rosa de Lima, Amigo, Mexicana, Suyapa, La Chapina and La Purisima Crema Nica.
The CDC says the elderly, pregnant women, newborns and adults with weakened immune systems are most susceptible to listeriosis.
It spreads through the consumption of contaminated foods such as uncooked meats and vegetables, unpasteurized milk and cheeses, and cooked and processed foods such as certain soft cheeses, ready-to-eat meats and smoked seafoods. Newborns can develop it if their mothers ate such tainted foods while pregnant.
A person with listeriosis usually has fever and muscle aches, diarrhea or other gastrointestinal symptoms, according to the CDC. They might also have headaches, a stiff neck, confusion, loss of balance or convulsions.