The Colorado Department of Public Health and Environment on Thursday announced three additional human cases of bird flu among poultry farm workers, bringing the total number of confirmed human cases in the U.S. this year to 13.
The three new cases involved poultry farm workers who were killing infected chickens at a Weld County egg farm, the health department said. The workers are experiencing mild illness and have been offered antiviral drugs, said the U.S. Centers for Disease Control and Prevention in a statement.
Neither the state health department nor CDC provided the name of the egg farm.
The bird flu outbreak has infected poultry in nearly every U.S. state since early 2022. Since March, the virus has been circulating among dairy cattle and has infected more than 170 herds in 13 states, according to the U.S. Department of Agriculture.
Since April, four dairy farm workers and nine poultry farm workers have been infected with the virus in Colorado, Michigan and Texas.