Listeria Outbreak Traced to Hot Dogs

A federal investigation has tracked the source of a food poisoning outbreak to hot dogs from Bil Mar's Zeeland, MI, meat plant, and recommends stronger steps against foodborne bacteria.

The Centers for Disease Control report said the same rare strain of bacteria that caused the outbreak was found in packages of Bil Mar hot dogs made at the Zeeland plant. It said the bacteria was likely present in the plant five months before the outbreak began.

But Jeffrey Smith, a spokesman for Bil Mar parent Sara Lee Corp., said the report ''indicates there is some uncertainty about the cause of the outbreak,'' and said the company was taking several steps to improve safety.

Bil Mar recalled 15 million pounds of hot dogs and lunch meats in December 1998 in one of the largest meat recalls ever because of suspected contamination with Listeria monocytogenes (See related article). Listeria-contaminated products from the plant have been linked to 100 illnesses in 22 states, as well as 15 deaths and six miscarriages or stillbirths.

CDC scientists found Listeria in a hot dog package with a sell-by date of June 1998, leading them to believe the bacteria was in the plant as early as April 1998—but not in levels high enough to cause an outbreak.

Over the July 4, 1998 weekend, a refrigeration unit in a room where hot dogs were readied for packaging was removed. The unit had to be chopped up to get it out of the building, and the CDC believes the pieces spread the bacteria through the plant as they were taken out.

The CDC said most of the plant's own tests for equipment contamination came back positive after July 4, and that the cooling unit was in the only area where hot dogs came in contact with machinery.

The first cases of the outbreak occurred in August 1998.

''Following a voluntary recall by the manufacturer, the number of listeriosis cases caused by the outbreak strain decreased abruptly, further confirming Plant Q (the Bil Mar plant) products as the sole source of the outbreak,'' the report said.

Smith pointed to parts of the report that said some cases could not be explained. The CDC said it was possible there were a few listeriosis infections that were unrelated to Bil Mar foods.

The report contained 15 recommendations for meat plants, the USDA and the CDC. It said ready-to-eat meats, such as hot dogs and deli foods, should be stamped with ''use-by'' dates, rather than ''sell-by'' dates. The CDC added that meat plants should treat hot dogs and other ready-to-eat meats after packaging, with heat or irradiating, to kill bacteria.

Since the recall, Sara Lee has hired a government food safety expert and promised to make several improvements in food safety. The company also is contributing $1 million for food safety research at Georgetown University's Center for Food and Nutrition Policy.