National meeting convenes on listeria outbreak
Judy Keller
Washington, DC — Government of ficials are pondering regulations to stem an “immediate public health problem” resulting from a recent outbreak of listeriosis, a disease caused by the deadly listeria monocytogenes bacterium.
Federal agriculture officials convened at a daylong public meeting — which included some 200 food industry executives, consumer groups and health experts and researchers — to discuss the record number of cases being reported nationwide.
The U.S. Department of Agriculture`s (USDA) Food Safety and Inspection Service (FSIS) has more questions than answers, officials say. FSIS plans to use information gathered at the meeting to create a short- and long-term strategy for regulation, education and enforcement efforts.
Tough questions
Thomas J. Billy, FSIS administrator, says the questions begging for answers include, “is our monitoring program for listeria adequate? Is the trend toward products with a longer shelf life increasing food safety risks? Are we doing enough to inform consumers about the hazards associated with deli meats and hot dogs?”
Those are tough questions in light of what appears to be an increasing contamination problem. A total of 16 deaths and more than 70 illnesses have been linked to listeria in products made by Sara Lee Corp. (Chicago). Additionally, between January 1 and February 18, the listeria recall list included dozens of products from Oscar Mayer Food Corp. (Madison, WI); Bosell Foods (Cleveland, OH); Culinary Foods Inc. (Chicago); Thorn Apple Valley Dixie Food Division (Forrest City, AR); BB Meat Sausage Mfg. Inc. (Bellingham, WA); Ba Le Meat Processing and Wholesale Inc. (Chicago); Kohler Mix Specialties Inc., a unit of Michael Foods (White Bear Lake, MN); and Tyson Foods (Springdale, AR).
The USDA is now considering putting warning labels on hot dogs and researching whether the shelf life of foods should be changed. Meanwhile, FSIS has launched a “Fight Bac” campaign to aid consumers in fighting the bacteria.
According to the Centers for Disease Control and Prevention (CDC; Atlanta), fewer than 2,000 people annually in the United States report serious illness from listeriosis, but one in four of those seriously ill from the disease die. FSIS reports show that in 1998 the USDA took a total of 3,547 product samples for listeria from some 2,000 plants in the United States. Ninety of the samples, or about 2.5 percent, tested positive.
Martin Wiedmann, a Cornell University researcher who was present at the February 11 meeting, has identified another method for containing the listeria bacteria. He is credited with limiting the death toll from the outbreak connected to Sara Lee`s manufacturing plant Bil Mar (Zeeland, MI).
Bil Mar officials voluntarily recalled about 35 million pounds of hot dogs and lunch meat on December 22, 1998, made over a six-month period, after Wiedmann pinpointed the source of the outbreak that killed 16 people.
Wiedmann, who has been studying listeria for seven years, helped the CDC determine the strain`s unique genetic fingerprint.
According to Dale Morse, director of the Division of Infectious Diseases at the New York State Department of Health, the outbreak may not have been recognized so quickly without Weidmann`s effort. Each month, the New York state health department sends Wiedmann listeria strains, which are added to an electronic database containing genetic blueprints of approximately 800 strains.
“This is the first instance where there is documented multiple people infected from the same source, ” Wiedmann says. “We could fingerprint rapidly because we already had a surveillance system in place.”
He used equipment called a RiboPrint made by Qualicon Inc., a division of DuPont. The RiboPrint can genetically “fingerprint” bacteria strains in about eight hours and print out a picture resembling a bar code that can be compared with the “blueprint” of other strains, Wiedmann explains.
He said the method is useful in diagnosing contamination problems in processing plants because it can pinpoint the source of contamination.