The company on Tuesday ceased operations at its Missouri plant after the reported illnesses were brought to its attention by the US Department of Agriculture's Food Safety and Inspection Service (USDA FSIS). ConAgra said it believes the issue is likely linked to consumers undercooking the not-ready-to-eat frozen products in question - Banquet Turkey and Chicken Pot Pies. Nevertheless, in agreement and collaboration with USDA, the firm is advising consumers not to eat these products while investigations are being carried out. It is also working on revising its product packaging in order to make cooking instructions clearer. FSIS said these products were considered the potential source of reported illnesses caused by salmonella based on epidemiological evidence collected by the Centers for Disease Control and Prevention (CDC) and State public health departments. This followed a multi-state case control study launched on October 3, which included detailed questions on chicken and egg consumption. Based on additional information provided by the Minnesota Department of Health, CDC added questions to the study on October 5 focusing on frozen chicken or turkey pot pie product consumption. FSIS was notified on October 5 that states had identified a product as the potential source of contamination. After discussions with CDC and the states throughout the weekend, on October 8 FSIS dispatched investigators to gather additional information at ConAgra's plant where these frozen pot pie products were produced. Until the source of contamination is identified, together with the exact products affected and their production dates, consumers have been advised not to eat any of these chicken or turkey pot pie items. The products are also sold under generic store brands, including brands for Wal-Mart, Food Lion, Kroger, Aldi, Meijer and HEB. Certain serotypes of Salmonella, which are known to cause human illness, are commonly found in raw meat and poultry. Other food sources, such as produce and eggs, are also known to cause salmonellosis. ConAgra was earlier this year at the center of another salmonella outbreak across the country. The firm's Peter Pan and Great Value branded peanut butter were linked to sickness that affected at least 425 people across 44 US states. ConAgra issued a massive recall at the time, and ceased production of the goods until a full investigation had been conducted. The company estimated that the recall would cost $60m. A report published in June this year by FSIS found that overall, the presence of salmonella in samples of most raw meat and poultry products tested by federal inspectors decreased slightly in the first quarter of 2006. The only increase was seen in ground beef, which was linked to a slight increase in salmonella rates. In February 2006, FSIS announced several changes to the agency's salmonella testing program, including a faster reporting of results to detect problems more rapidly. Future FSIS testing will incorporate sampling of turkey carcasses and increase testing frequency at plants with process-control problems. The change to the testing program is part of the FSIS' bid to reduce salmonella in raw meat and poultry products.