title: Risk Reduction Modeling of High Pathogenicity Avian Influenza Virus Titers in Nonpasteurized Liquid Egg Obtained from Infected but Undetected Chicken Flocks.
abstract: Control of highly pathogenic avian influenza (HPAI) outbreaks in poultry has traditionally involved the establishment of disease containment zones, where poultry products are only permitted to move from within a zone under permit. Nonpasteurized liquid egg (NPLE) is one such commodity for which movements may be permitted, considering inactivation of HPAI virus via pasteurization. Active surveillance testing at the flock level, using targeted matrix gene real-time reversed transcriptase-polymerase chain reaction testing (RRT-PCR) has been incorporated into HPAI emergency response plans as the primary on-farm diagnostic test procedure to detect HPAI in poultry and is considered to be a key risk mitigation measure. To inform decisions regarding the potential movement of NPLE to a pasteurization facility, average HPAI virus concentrations in NPLE produced from a HPAI virus infected, but undetected, commercial table-egg-layer flock were estimated for three HPAI virus strains using quantitative simulation models. Pasteurization under newly proposed international design standards (5 log10 reduction) is predicted to inactivate HPAI virus in NPLE to a very low concentration of less than 1 embryo infectious dose (EID)50 /mL, considering the predicted virus titers in NPLE from a table-egg flock under active surveillance. Dilution of HPAI virus from contaminated eggs in eggs from the same flock, and in a 40,000 lb tanker-truck load of NPLE containing eggs from disease-free flocks was also considered. Risk assessment can be useful in the evaluation of commodity-specific risk mitigation measures to facilitate safe trade in animal products from countries experiencing outbreaks of highly transmissible animal diseases.
authors: U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Science Technology and Analysis Services, Center for Epidemiology and Animal Health, Natural Resources Research Center, Bldg. B MS-2W4, 2150 Centre, Avenue, Fort Collins, CO 80526, USA.
authors: J Todd
authors: JT
authors: Weaver
authors: Center for Animal Health and Food Safety, University of Minnesota, 136 Andrew Boss Laboratory, 1354 Eckles Avenue, St. Paul, MN, 55108, USA.
authors: Sasidhar
authors: S
authors: Malladi
authors: U.S. Department of Agriculture, Agricultural Research Service, Southeast Poultry Research Laboratory, 934 College Station Road, Athens, GA, 30605, USA.
authors: Erica
authors: E
authors: Spackman
authors: U.S. Department of Agriculture, Agricultural Research Service, Southeast Poultry Research Laboratory, 934 College Station Road, Athens, GA, 30605, USA.
authors: David E
authors: DE
authors: Swayne
mesh_terms: D000818:Animals; D002645:Chickens; D009980:Influenza A virus / Q000472:pathogenicity*; D005585:Influenza in Birds / Q000821:virology*; D061352:Pasteurization; D040242:Risk Reduction Behavior
keywords: Continuity of business planning; highly pathogenic avian influenza; nonpasteurized liquid egg; risk assessment