Using the CDC’s estimate of the incubation period (from ingestion to onset of symptoms) from 3 to 70 days, Listeria-tainted deli meat could have been produced by Boar’s Head as early as mid-March 2024 (first illness reported May 29^th) with possible illnesses occurring at least 70 post-recall (July 30^th), or approximately mid-October.

According to the CDC, in most cases, Listeria infection causes fever and influenza- like symptoms resembling many other illnesses. Listeriosis has an extremely variable incubation period. It can range from 3 to 70 days, but symptoms usually appear within a month. CDC estimates that each year in the United States:

                  •               1,600 people are infected with Listeria, and

                  •               260 people die from the infection.

The first recall of approximately 200,000 pounds of Boar’s Head deli meat occurred on July 26^th and the expanded recall of an additional 7,000,00 pounds of Boar’s Head deli meat occurred on July 30^th.

Also according to the CDC, as of August 27, a total of 57 people infected with the outbreak strain of Listeria have been reported from 18 states. Sick people’s samples were collected from May 29, 2024 to August 16, 2024. Of 57 people with information available, all 57 have been hospitalized. One person got sick during their pregnancy and remained pregnant after recovering. Nine deaths have been reported, including one in Illinois, one in New Jersey, one in Virginia, and as of this update one in Florida, one in Tennessee, one in New Mexico, one in New York, and two in South Carolina.

Finally, the true number of sick people in this outbreak is likely higher than the number reported, and the outbreak may not be limited to the states with known illnesses. This is because some people recover without medical care and are not tested for Listeria. In addition, recent illnesses may not yet be reported as it usually takes 3 to 4 weeks to determine if a sick person is part of an outbreak.