Back to listeria control

While the use of whole genome sequencing became a running theme throughout the session, speakers focused on the challenges faced by the food industry in reducing the incidence of the listeria pathogen.

“There is no one in the food industry who is not concerned about being hit by this,” said Anthony Huggett, vice-president and head of quality management for Nestle S.A., Vevey, Switzerland. “All food sectors are hit by this and an industry-wide response is necessary.”

Dr. Tauxe said approximately 800 cases of listeriosis occur in the United States each year, that almost all who are infected are hospitalized and an estimated 16% die. Key foods identified as sources include raw milk, soft cheeses and mung bean sprouts. Recently such novel foods as caramel dipped apples and ice cream have been implicated in outbreaks.

Raw milk and soft cheese
Key foods identified as sources of listeria include raw milk and soft cheeses.

One industry group that has had success in controlling listeria is processed meats manufacturers. John Butts, Ph.D., vice-president of research for the processed meats manufacturer Land O’ Frost, Munster, Ind., and president of Food Safety by Design, a consultancy, said processed meat companies have been measured for listeria by the U.S. Department of Agriculture’s Food Safety and Inspection Service for the past 25 years and, over time, the per cent of positive results have declined.

John Butts
John Butts, Ph.D., vice-president of research for Land O’ Frost

“It’s this simple,” he said. “Eliminate the residents, control transfer of the organism and deploy process management techniques.”

Best practices he said have proven essential to listeria control in the meat industry include having clean, dry floors that do not have cracks. Equipment should require one tool or no tools for disassembly to be cleaned. Cleaning-out-of-place should be used for small parts, equipment sub-assemblies, and hand tools. Heat intervention should be used on large equipment.

“I started cooking slicers in 1998,” he said.

Companies should also consider the installation of critical air handling systems.

“They cost us twice as much, but we got a great return,” he said.

The ceiling space above processing areas must be considered as well as the separation of raw and ready-to-eat raw materials.

“I’m not talking about a yellow line on the floor,” he said. “There needs to be actual separation.”

Donna Garren
Donna Garren, Ph.D., senior vice-president of regulatory and technical affairs for the American Frozen Food Institute

Donna Garren, Ph.D., senior vice-president of regulatory and technical affairs for the American Frozen Food Institute, McLean, Va., emphasized that when the processed meat industry came together to work on the issue they saw the number of listeria incidents decline.

“This is a global issue and we all need to work together,” she said.