Can you tell if deli meats are contaminated with Listeria monocytogenes or other pathogens? Some recent news articles claiming that you may be able to determine if the meats are safe to eat from appearance and smell had us examining this issue. Given the deadly Listeria monocytogenes outbreak in 2020 that was linked to deli meats, and another in 2019, this information is important.
A new study published in the International Journal of Food Microbiology, headed by Fernando Sampedro of the University of Minnesota found that deli meats are associated with 90% of listeriosis cases in the United Sates. Other potentially hazardous foods include soft and semi-soft cheeses, ready to eat seafood, and frozen vegetables.
Listeria causes between 1,044 and 2,089 cases of illness in the United States every year. People who are most seriously affected by this infection include the very young, the elderly, pregnant women, anyone with a compromised immune system, and people with chronic illnesses. Most of these people need to be hospitalized because they are so ill. The study adds that, “the increasing proportion of elderly and high-risk populations (i.e., cancer and AIDS survivors) in recent years may be responsible for the steady listeriosis incidence rate.”
So can you tell if these meats are safe to eat by looking at them, or smelling them? No.
The pathogens that cause serious illness, including Listeria monocytogenes, Salmonella, Campylobacter, and E. coli, do not change the taste, texture, appearance, or aroma of any food, including deli meats. Deli meats contaminated with these pathogens will look, smell, and taste completely normal.
If a food smells strange, looks off, or tastes bad, it is probably contaminated with spoilage pathogens. Those pathogens may make you sick, but you most likely will not become seriously ill.
To protect yourself, consider avoiding these foods if you fall into one of the high risk groups. You can also heat deli meats until they reach 160°F on a reliable food thermometer. If you do choose to eat deli meats, keep an eye out for outbreak announcements and recalls from the CDC and FDA.
