Bird Flu on the Rise

The third human case of bird flu was identified in June, making it the second case in Michigan and the third associated with an ongoing, multi-state outbreak of bird flu in dairy cows. All human cases have been found in dairy farm workers exposed to infected cows.

In turn, U.S. federal and state agencies are planning to conduct research into potential respiratory spread of bird flu among dairy cattle. Last week, the Michigan Department of Agriculture and Rural Development began to offer dairy operations with bird flu up to US$28,000 to work with federal and state government agencies to investigate how bird flu was introduced into their operations to research how the virus spreads. This correlates with the U.S. Centers for Disease Control and Prevention’s (CDC) recommendation for heightened testing for influenza this summer—especially influenza A virus.

Since 2020, bird flu has become endemic in bird populations, causing an animal pandemic affecting at least 26 mammal species, The Lancet reported. It spread to dairy cows this year, and as of June 20, bird flu has been confirmed in 115 dairy cow herds across 12 U.S. states, according to the American Veterinary Medical Association. In response, 24 companies are working to develop a bird flu vaccine for cattle, Reuters reported.

Tests so far indicate that the virus detected in dairy cattle is the same clade that has been affecting wild birds and commercial poultry flocks. The same virus has also been sporadically detected in several species of wild mammals, including mice and neonatal goats. The virus has also affected domestic animals, with sick or dead cats testing positive for bird flu on dairy farms. Alpacas, which were near bird flu-affected poultry, also tested positive.

A growing concern across the world, the World Health Organization (WHO) has confirmed bird flu cases in humans in India, Australia, and Mexico. But the virus has not spread easily among humans, with 893 human cases—including 11 this year—reported since 2003, WHO reported.