Sunflower State Radio A Kansas State University researcher has published findings linking milking practices to the transmission of bovine H5N1 influenza virus, which affects dairy cattle and was first detected in the U.S. in spring 2024.
Juergen Richt is the senior author of the paper “H5N1 clade 2.3.4.4b dynamics in experimentally infected calves and cows,” which was published Sept. 25 in the journal Nature. Richt is a regents distinguished professor, university distinguished professor in diagnostic medicine and pathobiology, and director of the College of Veterinary Medicine’s Center of Excellence for Emerging and Zoonotic Animal Diseases.
Highly pathogenic H5N1 avian influenza has affected more than 200 dairy cattle farms in 14 states. Milking equipment and anthropogenic activities were suspected to be involved in transmission, but clear evidence of the mode of transmission has been lacking.
In a collaborative effort, research teams led by Richt and Martin Beer from the Friedrich Loeffler Institute in Germany experimentally infected both calves and lactating cows with H5N1 clade 2.3.4.4b virus, the strain of the virus circulating in cattle in the U.S., to gain insight into likely modes of transmission. They compared susceptibility and transmission in nine calves infected by oral and nasal inoculation and three lactating cows via inoculation of the mammary gland. In addition, the mammary glands of three other dairy cows were inoculated with H5N1 euDG, the avian influenza clade 2.3.4.4b strain that is circulating in Europe.