The presence of highly pathogenic avian influenza (HPAI) was confirmed in a commercial flock of table egg layer pullets in Lancaster County, Pennsylvania.

The United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) reported that the case was confirmed on February 8 and involved 20,300 pullets.

This marks Lancaster County’s tenth case of HPAI during the 2022-23 outbreak, and the second case in 2023. The county’s other 2023 case was confirmed on February 1 in a commercial meat duck flock, with 32,000 birds affected.

Pennsylvania has had a total of 27 confirmed HPAI cases in commercial poultry since the virus was first detected on April 15, 2022, also in Lancaster County. That case involved nearly 1.4 million commercial table egg layers.


Only Minnesota and South Dakota have had more cases of HPAI than Pennsylvania during the 2022-23 outbreak. Minnesota has had 81 cases and South Dakota has had 61, although neither state has had any positive HPAI detections in commercial poultry so far in 2023.

Also on February 8, HPAI was confirmed in a commercial upland gamebird flock in Mitchell County, Kansas. That flock involved 17,000 birds. A separate article appears on concerning that case. Other states with confirmed cases of HPAI in 2023 include Mississippi, Tennessee, Virginia, Iowa and California.

To learn more about HPAI cases in commercial poultry flocks in the United States and Canada, see an interactive map on 

Read our ongoing coverage of the global avian influenza outbreak.