Submitted to: International Association for Food Protection Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/2007
Publication Date: 7/8/2007
Citation: Thomas, C., Swayne, D.E. 2007. Thermal inactivation of high pathogenicity avian influenza viruses in chicken meat [abstract]. In: Proceedings of the 94th Annual Meeting of the International Association for Food Protection, July 8-11, 2007, Buena Vista, Florida. p. 150. Interpretive Summary:
Technical Abstract: High pathogenicity avian influenza (HPAI) viruses cause severe disease with high mortality in chickens and related gallinaceous poultry. Some HPAI viruses cause systemic infections and replicate to high titers in skeletal muscle fibers. To prevent transmission of these viruses through contaminated meat, the World Organization for Animal Health (OIE) recommends trading poultry products from countries, zones, or compartments infected with avian influenza subtypes H5 or H7 only when the products are effectively processed to destroy these pathogens. To determine thermal inactivation parameters for HPAI in chicken meat, thermal inactivation of the HPAI strains A/chicken/Korea/ES/2003 (H5N1) and A/chicken/PA/1370/83 (H5N2) was quantitatively measured in meat harvested from infected chickens. Small (0.5 g) pieces of meat were placed in thin-walled PCR tubes and heated in a thermocycler block. After heat treatment, the meat samples were ground with small pestles to release virus from the tissue, and the supernatants were tested for virus inactivation by titration in embryonating chicken eggs. The times required for a 90% reduction in virus titer (D-values) were calculated for each HPAI strain at temperatures ranging from 57 degree C to 61 degree C in 1 degree C intervals, and line equations describing the thermal inactivation of each HPAI strain were generated from graphs of D-value (log scale) versus temperature. Similar D-values were predicted by the line equations for each HPAI strain at each temperature tested. However, the temperature increase needed to reduce the D-value by 90% (z-value) for the H5N2 strain (4.1 degree C) was 0.5 degree C lower than that for the H5N1 strain, indicating that a slightly higher sensitivity to increasing temperature was observed with the H5N2 samples. Each line equation predicts that cooking chicken meat according to current USDA-FSIS time-temperature guidelines for a 7-log reduction of Salmonella will inactivate HPAI in a heavily contaminated meat sample with a large margin of safety.