The Centers for Disease Control and Prevention (CDC), public health and regulatory officials in several states, and the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA-FSIS) are collecting different types of data to identify the food source of a multistate outbreak of Listeria monocytogenes infections. As of July 19, 2024, a total of 28 people, all of whom have been hospitalized, have been reported in 12 states. One person got sick during their pregnancy and remained pregnant after recovering. Two deaths have been reported, one in Illinois and one in New Jersey. Other states in the outbreak included in the outbreak are Minnesota, Wisconsin, Missouri, Pennsylvania, New York, Virginia, North Carolina, Georgia, Massachusetts and Maryland.

Epidemiologic information shows that many people in this outbreak reported eating meats sliced at deli counters. Of the 18 people able to be interviewed, 16 (89%) reported eating meats sliced at a deli, most commonly deli-sliced turkey, liverwurst, and ham. Meats were sliced at a variety of supermarket and grocery store delis.

According to the CDC, Listeria can cause severe illness (known as invasive listeriosis) when the bacteria spread beyond the gut to other parts of the body. Pregnant people typically experience only fever, fatigue, and muscle aches. However, Listeria infection during pregnancy can lead to miscarriage, stillbirth, premature delivery, or life-threating infection of the newborn. People who are not pregnant may experience headache, stiff neck, confusion, loss of balance, and convulsions, in addition to fever and muscle aches. Symptoms of severe illness usually start 1 to 4 weeks after eating contaminated food with Listeria but may start as early as the same day or as late as 70 days after.

“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,” the agency reported, adding that recent illnesses may also not yet be reported as it usually takes 3 to 4 weeks to determine if a sick person is part of an outbreak.

The CDC is advising people who are pregnant, aged 65 or older, or have a weakened immune system to contact their healthcare provider if they have any Listeria symptoms.  Additionally, CDC advises people to take steps to protect themselves from getting Listeria from deli meats by avoiding eating meats sliced at the deli unless they are heated before eating.