The Colorado Department of Public Health and Environment announced Thursday that three reported cases of Listeria infection, two of which resulted in death, had been reported in Denver since May 20.  

According to a press release issued by the state health department, the two people who died were a male in his 30s and a female in her 60s.  All three Listeria cases were people of Hispanic/Latino heritage.  

Although the state, Denver Public Health and Denver Environmental Health continue to investigate the reported cases, the source of the outbreak is unknown and public health officials are urging residents to take basic precautions to prevent infection.  

“People who are at high risk for Listeria infection can decrease their risk by avoiding soft cheeses such as queso fresco and brie unless they are made with pasteurized milk, hot dogs and deli meats unless reheated to an internal temperature of 165F, refrigerated pâté or meat spreads, or refrigerated smoked seafood,” Alicia Cronquist, an epidemiologist at the state health department, said in a statement.

Consumption of food contaminated with Listeria monocytogenes can cause Listeria infection, which is also known as listeriosis, an uncommon but potentially fatal infection. Healthy people rarely contract listeriosis, but immunocompromised individuals, pregnant women, and people age 60 or older are at high risk.   

Symptoms can include fever and muscle aches, and also can include diarrhea, headache, stiff neck, confusion and convulsions. Listeriosis also can cause miscarriages and stillbirths.

Antibiotics given promptly can cure the illness and prevent infection of a fetus. Even with prompt treatment, some Listeria infections result in death. This is particularly likely in older adults and in people with other serious medical problems.