Bird flu has spread among 168 dairy herds in the U.S., with seven cases documented in humans since the 2022 outbreak. The outbreak began in February 2022 when the USDA reported an outbreak of highly pathogenic avian flu in an Indiana turkey flock, the first case in a commercial poultry operation since 2020. The H5N1 bird flu virus has spread to dairy cows in the United States, raising concerns about its spread to humans, infecting more than 100 million chickens and over 9,500 wild birds. Health experts have raised concerns over the disposal of infected poultry birds as the avian flu continues to spread.
In July, Colorado reported the fifth and sixth cases of bird flu in humans this year, with four previously confirmed human cases in the state. The U.S. Centers for Disease Control and Prevention confirmed two additional cases in Colorado poultry farm workers, while preliminary results from blood samples from 35 Michigan dairy farm workers did not show the presence of the H5N1 virus. Oklahoma became the 13th state to detect bird flu in dairy cows, with Moderna receiving a $176 million award from the U.S. government to advance the development of its bird flu vaccine.
In June, Wyoming became the 12th state to report an infected dairy herd, followed by Minnesota as the 11th state and Iowa as the tenth state to report an infection in a herd. The third case of bird flu in humans this year was reported in May after a dairy worker in Michigan tested positive, and another case was confirmed in May when a dairy worker in Michigan was infected. In April, Colorado reported the ninth infected dairy herd in the U.S., prompting Colombia to restrict beef imports from U.S. states with bird flu in dairy cows.
The U.S. government tightened restrictions on the movement of dairy cows between states in April and detected bird flu virus particles in some samples of pasteurized milk but assured the public that the milk supply remained safe. South Dakota became the eighth state to find avian influenza in a dairy herd, while the outbreak spread to an Ohio herd, and Mexico took preventative measures after finding bird flu in dairy cattle. The second known human case of bird flu in the United States was reported in a person from Texas who had contact with infected dairy cows.
Throughout the year, the USDA tested bird flu vaccines for poultry after more than 58 million chickens, turkeys, and other birds died in the nation’s worst outbreak. The outbreak has resulted in the deaths of more than 47 million birds, with millions of commercially raised chickens and turkeys being killed due to the highly lethal type of bird flu. The first known human case of H5N1 bird flu in the United States was reported in Colorado in April, with millions of birds being culled or killed to control the spread of the disease. Overall, the avian flu outbreak has spread to multiple states, raising concerns about its impact on both animals and humans.
