Mitigation of Highly pathogenic influenza (HPAI) in milk and dairy products

Project Summary/AbstractHighly Pathogenic Avian Influenza (HPAI) H5N1 virus is an emerging pathogen in dairy cattle with zoonoticpotential. Recently HPAI H5N1 spilled over into dairy cattle and studies demonstrated the tropism of the virusfor the mammary gland with the virus replicating in milk secreting cells in this tissue leading to high levels ofvirus shedding in milk of affected cows. This property has caused major public health and consumer concernsas milk and dairy products are consumed in large scale by the population in the US. While pasteurization isdesigned to reduce potential bacterial and viral pathogens in commercial shelf milk and have been shown to beeffective by us and others to inactivate HPAI raw milk which is handled in large quantities in farms represents amajor risk factor for HPAI spread and transmission. Indeed recent investigations by Dr. Diels group and othershave shown that raw milk can serve as a route of transmission of the virus to cats. The practice of feedingunpasteurized raw milk to calves and other animals in dairy farms poses a risk for spread and dissemination ofthe virus. Given the high levels of HPAI virus present in milk from affected animals disposal of raw non-saleablemilk from those animals is a major problem as the contaminated milk may serve as source of infection to otheranimals birds and potentially humans. This needs to be urgently addressed to minimize environmentalimpact of HPAI and to prevent its spread between dairy farms and from affected dairy farms to othersusceptible species. In the present project we will address this significant issue and will perform studies toimprove our understanding of the risks posed by raw milk and raw milk cheeses and to identify potentialmitigation strategies to inactivate HPAI in raw milk and raw milk products. To accomplish this we propose fourspecific aims: 1) to define efficacy of raw milk cheese aging on inactivation of HPAI; 2) to characterize the thermalinactivation kinetics of HPAI H5N1 in dairy products; 3) to identify effective mitigation strategies to treat raw wastemilk prior to disposal or feeding to animals; and 4) to enhance capabilities and capacity for HPAI H5N1 testingin support of FDAs research agenda. To achieve these goals and establish a long-term partnership with FDA webrought together a transdisciplinary team of investigators with complementary expertise in virology (Drs. Dieland Nooruzzaman) food safety microbiology and dairy product processing (Drs. Martin and Alcaine) and onfarm clinical and management practices (Dr. Mann). Successful completion of the study will provide acomprehensive understanding of the inactivation kinetics and efficiency of inactivation of HPAI in milk and severalother dairy products including high risk products such as raw milk cheeses. Thus the project is directly alignedwith the FDA goals and mission.