Colorado health officials warned Thursday that an outbreak of listeria cases has led to two deaths since May 20, a cause for concern when the state averages only 10 bouts of the illness a year. Colorado Department of Public Health and Environment epidemiologists said three cases of listeria infection involving people of Latino heritage had resulted in two deaths. The dead were a man in his 30s and a woman in her 60s.
Listeria is an infection caused by bacterium named Listeria monocytogenes that produces fever, muscle aches, and in many people, diarrhea. Severe infections can cause headaches, meningitis, convulsions, and death. Most healthy people exposed to the bacteria have minor or no symptoms, but a few people, especially the elderly, pregnant women and their fetus, newborns, and anyone with a compromised immune system are especially susceptible to these organisms.
The source of the Colorado outbreak remains unknown, while state and Denver public-health officials work to isolate it. A state epidemiologist said there was no apparent relationship among the three victims of the illness. Investigators will look at foods eaten by the victims in the past month, the sources of the food and other factors as they try to isolate the source.
People at high risk are cautioned to avoid soft cheeses, such as brie or queso fresco, unless made with pasteurized milk; and deli meats or hot dogs not fully cooked to 165 degrees. The warning list also includes “refrigerated smoked seafood” and other meat spreads.