Nine people have now died in a listeria outbreak linked to recalled Boar’s Head deli meat, the Centers for Disease Control and Prevention (CDC) said in an update on Wednesday.
The announcement adds six additional confirmed fatalities since the CDC announced on Aug. 8 that three people had died in connection to the outbreak.
At least 57 people have now been reported to be sickened by the illness, 14 more than the total reported earlier this month. All of those individuals have been hospitalized, the CDC said.
The outbreak extends to 18 states, and the nine deaths have been reported from a total of eight states. The six new deaths included one in Florida, one in Tennessee, one in New Mexico, one in New York and two in South Carolina. The first three were reported in Illinois, New Jersey and Virginia.
The CDC said Wednesday it is the largest listeria outbreak since the 2011 outbreak linked to cantaloupe and warned more people are likely affected beyond the 57 confirmed cases.
“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,” the CDC said.
The agency reiterated that many people recover from listeria without medical care and are therefore never tested for it. It could also take up to four weeks to determine whether a sick person is connected to the outbreak, so recent illnesses may not be included in the total.
Boar’s Head initially recalled its Strassburger Brand Liverwurst in late July because it “had the potential to be adulterated with Listeria monocytogenes,” according to the company’s website. It also recalled nine other products made on the same assembly line at the Jarratt, Va. facility.
The Maryland Department of Health then confirmed a liverwurst sample tested positive for listeria. In response, four days later, Boar’s Head expanded its recall to include all of the items produced at the Virginia facility — totaling 7 million pounds.
None of the recalled items are currently available for sale, the company said. But health officials are warning people to check their refrigerators for any recalled deli meats and to make sure to clean refrigerators, containers and surfaces thoroughly that may have touched the recalled meats.
“Listeria is a hardy germ that can remain on surfaces, like meat slicers, and foods, even at refrigerated temperatures,” the CDC said, warning of the potential contamination on deli counters in particular.
The CDC said refrigeration does not kill the germs but reheating the meat to “a high enough temperature before eating” will kill them.
Listeria is especially harmful to those who are pregnant, older than 65 or have weakened immune systems.
Symptoms usually develop within two weeks of eating contaminated food, but they can develop as soon as the same day or as late as 10 weeks later, the CDC said.
Symptoms include fever, muscle aches and tiredness. Those who are not pregnant may also develop a headache, stiff neck, loss of balance or seizures, according to the CDC.