Listeria outbreak linked to deli foods reaches California

A listeria outbreak likely linked to contaminated deli meat and cheese has sickened at least 16 people nationwide, including one person in California.

The outbreak has been deadly. One Maryland resident has died. Another sickened person was pregnant, and the illness resulted in the loss of the pregnancy, the U.S. Centers for Disease Control and Prevention said. Pregnant women are 10 times more likely than other people to get a listeria infection, which can cause miscarriages, stillbirths and preterm labor.

Older people and those with weakened immune systems who are infected with listeria can suffer severe infections of the bloodstream, leading to sepsis, or infections of the brain, causing meningitis or encephalitis, the CDC said.

At least 13 of the 16 cases required hospitalization. It was not immediately known where the person infected in California lived.

Pregnant women, older people and those with weakened immunity have long been advised to avoid eating cold cuts and other deli meats unless heated to an internal temperature of 165 degrees Fahrenheit or until steaming hot just before eating.

The CDC issued a bulletin Wednesday summarizing a long-lasting listeria outbreak, with the highest number of cases in a single state — seven — identified in New York.

“Among seven sick people in New York, five bought sliced deli meat or cheese from at least one location of NetCost Market, a grocery store chain that sells international foods. Sick people from other states purchased deli meats or cheeses from other delis,” the CDC said.

Officials don’t believe the New York-based chain is the only source of contaminated food “because some sick people in the outbreak did not shop at a NetCost Market. A contaminated food likely introduced the outbreak strain of listeria into delis in multiple states,” the agency said.

The CDC suspects the 16 cases — involving people sickened as early as April 17, 2021, and as late as Sept. 29, 2022 — are connected because analyses of the bacteria identified in the cases are “closely related genetically.”

“This suggests that people in this outbreak got sick from the same food,” the agency said.

Other cases of listeria identified in this outbreak include three in Maryland, two each in Illinois and Massachusetts, and one in New Jersey.

“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. “This is because some people recover without medical care and are not tested for listeria.”

More recent illnesses may not have been reported because it generally takes three to four weeks to determine whether someone who has fallen ill is connected to an existing outbreak.

Those who became ill ranged in age from 38 to 92, with a median age of 74, the CDC said.

Symptoms of listeria infection in pregnant women can appear like the flu, such as fever, fatigue or muscle aches. But listeria illness while pregnant results in fetal loss in 20% of cases and newborn deaths in 3% of cases.

“If infection occurs during pregnancy, listeria bacteria can spread through the placenta,” the CDC said.

Symptoms in people who are not pregnant can include stiff neck, confusion, loss of balance, convulsions, fever, fatigue and muscle aches.

It generally takes one to four weeks after eating contaminated food to show symptoms. But sometimes, they can be detected on the same day or as long as 70 days later.

Antibiotics can be used to treat listeria illness.