The CDC suspects Italian-style meats, such as salami, mortadella, and prosciutto, as the source, although the health agency has not yet specifically identified the products involved. Infected patients reported purchasing prepackaged deli meats and meats sliced at deli counters at various locations. The majority of the cases tied to the outbreak (seven) have been in Massachusetts, while two people have been hospitalized in New York, and one person in Florida has died. The median age of those individuals is 81, and the majority are female. “Listeria can be very dangerous, and I think particularly so in older persons, because it clearly can cause systemic illness with bloodstream infections,” says William Schaffner, MD, an infectious disease specialist and professor of preventive medicine and health policy at the Vanderbilt University School of Medicine in Nashville, Tennessee. Dr. Schaffner was not surprised to see a primarily older population succumbing to the illness. The CDC warns that people age 65 and older face a higher risk of getting severely sick from listeria. Pregnant women, who also have weakened immune systems, have a greater chance of becoming seriously ill as well. The CDC recommends that these high-risk populations avoid eating deli meats, unless heated to an internal temperature of 165 degrees F or until steaming hot just before serving. It also suggests keeping deli meats isolated from other items, even in the refrigerator, because the bacteria can still survive in cool temperatures and spread to other foods and surfaces. The federal health agency estimates that about 1,600 people get listeriosis (the infection caused by the bacteria Listeria monocytogenes) each year, and about 260 die. In addition to diarrhea, nausea, and fever, patients may experience fever, chills, and muscle aches. The Mayo Clinic cautions that listeria infection can spread to your nervous system, producing headache, stiff neck, confusion or changes in alertness, loss of balance, and convulsions. While symptoms can appear soon after eating contaminated food, the first signs of infection can take up to 30 days or more to appear. Listeriosis can be successfully treated with antibiotics if diagnosed early. However, Jennifer Horney, PhD, professor of epidemiology and core faculty with the Disaster Research Center at the University of Delaware in Newark, says, “a challenge with listeria is a relatively long incubation period of one to four weeks, so it may be difficult for people at risk to remember specific food or beverage exposures. Contact your medical care provider or local health department if you are concerned about exposure, and be sure to throw out any products you may have purchased that are included in recalls.” Concerned consumers should check the CDC website as the investigation continues and details about the source of the outbreak further develop. “There are likely more cases,” says Schaffner. “This is probably just the tip of the iceberg.”
