As U.S. health officials investigate a deadly outbreak of Listeria food contamination, they are advising people who are pregnant, elderly or have compromised immune systems to avoid eating deli meats unless they recook them at home until they are piping hot.
As of early Saturday, the Centers for Disease Control and Prevention had not ordered any recalls because it is unclear which specific products have been contaminated with the bacteria that has been blamed for two deaths and 28 hospitalizations in 12 states. That means they may still be in circulation, and consumers should be aware of the risk they face when eating sausages.
Federal health officials warned Friday that the number of reported cases is likely an undercount because people who recover at home are often not tested. It’s possible the outbreak has spread beyond the states where listeria infections have been reported, primarily in the Midwest and along the East Coast.
The largest number of known cases — seven — have been in New York, according to the CDC. Deaths have occurred in Illinois and New Jersey.
What have researchers found out?
Of the people researchers were able to interview, “89 percent reported eating sliced meat at a grocery store, mostly turkey, liverwurst and ham. The meats were sliced at different grocery stores and convenience stores,” according to the CDC.
Samples collected from victims between May 29 and July 5 show the bacteria are genetically related.
“This information suggests that store-bought sliced meats are a likely source of this outbreak. However, at this time CDC does not have enough information to say which deli meats are the source,” the agency said in a statement posted Friday on its website.
What happens to infected people?
Listeria infections often cause fever, muscle aches and fatigue. They also cause a stiff neck, confusion, loss of balance and seizures. Symptoms may appear quickly or up to ten weeks after eating contaminated food.
Diagnosis is made through analysis of body fluids, usually blood, and sometimes urine or spinal fluid, the Mayo Clinic notes.
According to the CDC, listeria infections are especially dangerous for people over 65 years of age and those with weakened immune systems. Victims of this outbreak ranged in age from 32 to 94, with an average age of 75.
Listeria increases the risk of miscarriages in pregnant women. One victim of the current outbreak was pregnant but did not miscarry, officials said.
Infections confined to the intestine (intestinal listeriosis) can be treated without antibiotics, according to the CDC. Those with diarrhea, for example, need to drink more fluids.
But when the infection spreads beyond the intestine (invasive listeriosis) it is extremely dangerous and must be treated with antibiotics to mitigate the risk of blood infections and brain inflammation, the Mayo Clinic says.
What can you do with the meat you already bought?
So far, there’s no evidence that people are getting sick from packaged deli meats. And those at risk who already have deli meats in their refrigerator can sanitize them by recooking them. “Refrigeration does not kill listeria, but reheating meats before eating them will kill any germs that may be on them,” the CDC says.
This advice isn’t new: The CDC consistently recommends that people at higher risk for listeriosis avoid eating store-cut meats, or heat them to an internal temperature of 165 Fahrenheit (74 Celsius) or until steaming hot.
Some of the products that have caused listeria outbreaks in the past cannot be reheated. Cheese, milk, mushrooms, salads and ice cream have all had to be recalled for decades.
