Another commercial laying hen flock in Colorado has been affected by H5N1 highly pathogenic avian influenza (HPAI).
The United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) reported that the presence of HPAI was confirmed on July 16 in a flock of 1,313,800 chickens in Weld County.
This is the second Weld County egg production flock to be affected by HPAI in July. On July 8, the presence of HPAI was confirmed in another flock, with that one involving 1,790,000 birds, collectively bringing that county’s bird losses beyond 3.1 million.
The only other instance of HPAI to be confirmed in a Colorado commercial poultry flock in 2024 involved a flock of 66,500 broiler breeders in Delta County. That case was confirmed on February 8.
H5N1 in humans, cattle
State and federal health officials are investigating a human outbreak of H5N1, in which four workers responding to an H5N1 avian influenza outbreak in Colorado have confirmed cases of highly pathogenic avian influenza (HPAI) while a fifth worker is a presumed-positive case.
According to a press release from the Colorado Department of Public Health and Environment (CDPHE), the workers were culling poultry at a commercial laying hen operation in the state and exhibited mild symptoms, including conjunctivitis and common respiratory infection symptoms. However, none of the patients required hospitalization.
The U.S. Centers for Disease Control and Prevention (CDC) and the CDPHE did not specifically state that this was a Weld County farm.
APHIS has also reported 33 cases of H5N1 in commercial dairy herds in the state.
View our continuing coverage of the global avian influenza situation.
To learn more about HPAI cases in commercial poultry flocks in the United States, Mexico and Canada, see an interactive map on WATTPoultry.com.
