Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Virus Infection in Domestic Dairy Cattle and Cats, United States, 2024

• Published in: Emerging infectious diseases Vol. 30; no. 7; pp. 1335 - 1343
• Main Authors: Burrough, Eric R., Magstadt, Drew R., Petersen, Barbara, Timmermans, Simon J., Gauger, Phillip C., Zhang, Jianqiang, Siepker, Chris, Mainenti, Marta, Li, Ganwu, Thompson, Alexis C., Gorden, Patrick J., Plummer, Paul J., Main, Rodger
• Format: Journal Article
• Language: English
• Published: United States U.S. National Center for Infectious Diseases 01.07.2024; Centers for Disease Control and Prevention
• Subjects: Agriculture; Animal lactation; Animals; Antibodies; Avian flu; Avian influenza; Avian influenza viruses; Cats; clade 2.3.4.4b; Dairy cattle; Dairy farms; Development and progression; Disease transmission; Distribution; Domestic animals; Expedited; Genetic aspects; H5N1; Health aspects; highly pathogenic avian influenza A(H5N1); HPAI; Illnesses; Infection; influenza; Laboratories; Mammals; Milk production; Phylogenetics; Scientific equipment and supplies industry; Software; Viruses; United States; Texas; Kansas; United States > US; influenza; spillover; viruses; avian influenza; United States; highly pathogenic avian influenza A(H5N1); zoonoses; respiratory infections; H5N1; HPAI; cats; dairy cattle; bovine influenza A; clade 2.3.4.4b
• DOI: 10.3201/eid3007.240508
• ISSN: 1080-6040; 1080-6059

We report highly pathogenic avian influenza A(H5N1) virus in dairy cattle and cats in Kansas and Texas, United States, which reflects the continued spread of clade 2.3.4.4b viruses that entered the country in late 2021. Infected cattle experienced nonspecific illness, reduced feed intake and rumination, and an abrupt drop in milk production, but fatal systemic influenza infection developed in domestic cats fed raw (unpasteurized) colostrum and milk from affected cows. Cow-to-cow transmission appears to have occurred because infections were observed in cattle on Michigan, Idaho, and Ohio farms where avian influenza virus-infected cows were transported. Although the US Food and Drug Administration has indicated the commercial milk supply remains safe, the detection of influenza virus in unpasteurized bovine milk is a concern because of potential cross-species transmission. Continued surveillance of highly pathogenic avian influenza viruses in domestic production animals is needed to prevent cross-species and mammal-to-mammal transmission.