The US Centers for Disease Control and Prevention is reminding the public to avoid eating recalled deli meats amid a listeria outbreak that has expanded to become the nation’s largest since 2011.

Boar’s Head issued a recall in late July for more than 7.2 million pounds of its ready-to-eat liverwurst and some other deli meat products due to concerns about potential listeria contamination, but the CDC says at least a dozen more listeriosis cases have been reported in recent weeks.

Documents from the US Department of Agriculture that were first obtained by CBS News show that insects and mold were identified at the company facility that’s been linked with the recall.

A total of 57 people have been hospitalized in 18 states in connection with the outbreak, and nine people have died. The CDC says this listeria outbreak is now the largest since one linked to cantaloupe in 2011.

The agency has said that the true number of illnesses is probably higher than what’s been reported because some people may have had a milder case and were not tested for listeria. There’s also a lag time between when an illness happens and when scientists can connect it with an ongoing investigation.

The CDC advises consumers to check their kitchens for any remaining recalled products because they can have a long shelf life. Look for “EST. 12612” or “P-12612” inside the USDA mark of inspection on labels. Some of the products have sell-by dates into October 2024.

The recalled products include liverwurst, ham, bologna, sausage and roasted bacon. Most people who became sick reported eating turkey or liverwurst, and some reported eating ham.

However, Boar’s Head says any products now available at deli counters are not subject to recall.

Documents show reports of insects, mold

Insects and mold were identified at the Virginia Boar’s Head plant linked to the recall, according to USDA documents.

Reports from the USDA’s Food Safety Inspection Service show 84 “noncompliances” from January 2022 to August 2024, 69 of them since August 2023. They describe insects, alive and dead, in several areas of the Jarratt, Virginia, plant, at various times and mold seen on doors, near a hand-washing sink and on a ceiling at different points. One report from February 2024 described “blood in puddles on the floor” and a “rancid smell in the cooler.”

Boar’s Head said in a statement to CNN on Thursday that “We deeply regret the impact this recall has had on affected families. No words can fully express our sympathies and the sincere and deep hurt we feel for those who have suffered losses or endured illness.”

The company said it is working with food safety experts to investigate how liverwurst made at the Jarratt facility was adulterated and to keep such problems from happening again.

“As soon as we learned of a health risk with our liverwurst, we immediately recalled it and then, out of an abundance of caution, voluntarily expanded our recall to include every product made at the same facility,” the statement said. “We have paused production at this facility in Jarratt, Virginia, and will not resume until we are confident that it meets the standards our customers expect and deserve. Consumer health and wellness are, and always have been, our top priorities.”

The USDA’s Food Safety Inspection Service, known as FSIS, said it has suspended inspection at the Boar’s Head facility, “which means that it remains closed until the establishment is able to demonstrate it can produce safe product.”

According to the USDA, the facility is inspected by the Virginia Department of Agriculture and Consumer Services as part of the Talmadge-Aiken Cooperative Inspection Program, which allows some states to provide federal inspection services.

“Inspectors found instances of noncompliance, and the establishment implemented corrective actions in keeping with FSIS regulations,” the statement said. “FSIS is working closely with VDACS to ensure the establishment has an effective system in place to produce safe food for the public.”

Dangers of listeria

Listeria bacteria is hardy and can stay on surfaces like countertops and meat slicers, so you don’t even have to eat a contaminated product to get sick. It can spread easily at delis, the CDC says, transferring from equipment to surfaces to hands and food. Refrigeration does not kill the bacteria, but heat can.

People who are pregnant, those who are 65 and older, and those with weakened immune systems are advised to avoid eating any deli meat unless it’s been heated until it steams or reaches an internal temperature of 165 F.

If you’ve had sliced deli meat at home, clean the refrigerator and any containers or surfaces that may have come into contact with it, and watch out for symptoms of listeriosis, which can take up to 10 weeks to develop.

Listeria bacteria causes listeriosis, the third leading cause of death from foodborne illness in the United States.

Symptoms can include fever, muscle aches and fatigue. An infection can also cause a stiff neck, a headache, confusion or seizures.

Anyone who develops symptoms of listeriosis should get medical care right away.

The timeline of this outbreak stretches over several months, the CDC said, as the first person got sick at the end of May. The investigation is ongoing.

The CDC is encouraging people who get sick with listeria to work with local public health officials, who may get in touch to find out what they ate in the previous month and may ask for receipts or leftover food to help pinpoint the root of the outbreak.