CDC Launches New Webpage on H5N1 Bird Flu Virus in Mammals

The CDC website now features a new page dedicated to the current situation on highly pathogenic avian influenza (HPAI) A(H5N1) virus (“H5N1 bird flu”) in mammals. The page includes information on the outbreak of H5N1 bird flu in dairy cows in the U.S., the risk to people, a timeline of documented mammalian infections in the U.S. and globally, and a list of related links. See the page here.

A multi-state outbreak of HPAI A(H5N1) bird flu in dairy cows was first reported on March 25, 2024. This is the first time that these bird flu viruses were found in cattle. CDC confirmed one human HPAI A(H5N1) infection that had exposure to dairy cattle in Texas that were presumed to be infected with the virus. While thought to be rare, this exposure to HPAI A(H5N1) bird flu virus is the first instance of likely mammal to human transmission.