Hot topic: Influenza A H5N1 virus exhibits a broad host range, including dairy cows
Salman L. Butt, Mohammed Nooruzzaman, Lina M. Covaleda, Diego G. Diel
Abstract
), resulting in unprecedented efficient transmission of the virus in this species, the first case of sustained transmission in a mammalian species. The transmission pathways involved in the spread of the virus from its first detection in Texas to several other states are complex. However, movement of subclinically infected cattle likely played a major role in virus spread. Infection in dairy cattle is characterized by the virus's tropism for milk-secreting cells in the mammary gland, leading to high viral load and shedding in milk. Replication of the virus in milk-secreting cells results in destruction of infected cells leading to severe viral mastitis, which is characterized by marked changes in milk quality (altered consistency and color) and pronounced decline in milk production by clinically affected animals. Here, we provide an overview of the HPAI H5N1 panzootic virus and discuss its host range and the current knowledge of its pathogenesis in the new bovine host.