Food Source Is Probed in Northeast Listeria Deaths

PHILADELPHIA —  Listeria infections have killed at least 13 people in the Northeast, and although health officials say contaminated food is the likely cause, they’re still trying to determine the source of the infection.

Since an outbreak was first noticed in Pennsylvania in early September, cases have been detected in New York, New Jersey and Connecticut.

Four people have died in Pennsylvania, four in New Jersey and five in New York state. One apparently related death was also reported in Michigan.

Because a specific food associated with the cases had not been identified, health officials recommended that children, the elderly and people with weakened immune systems avoid certain foods, including soft cheeses, hot dogs and luncheon meats (unless reheated), and unpasteurized milk.

Listeria can cause serious, sometimes fatal, food poisoning. In adults, it can cause meningitis. In less-severe cases, it can cause headache, high fever, nausea, abdominal pain and diarrhea. Listeria sickens about 2,500 people and kills about 500 each year in the United States, according to the federal Centers for Disease Control and Prevention.

Pennsylvania has had 25 cases of listeriosis in the last two months, compared to a normal rate of about 24 cases a year, state Health Department spokesman Richard McGarvey said.

McGarvey said genetic fingerprinting indicated 10 of the nonfatal cases in Pennsylvania were caused by the same bacteria strain. Testing had not been completed to determine whether the four deaths were also caused by the strain, he said.

The four Pennsylvania residents who died were older than 65. The deaths occurred before Labor Day, and the most recent case there was found last week, McGarvey said.

Two New York City residents who died were among eight New Yorkers who contracted the same strain of the disease found in Pennsylvania.