WASHINGTON — Highly pathogenic avian influenza (HPAI) cases continue to emerge, particularly in commercial turkey operations.

According to the US Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS), three counties in South Dakota shared large numbers of birds that were affected.

On Nov. 29, an outbreak in a commercial turkey flock in Hanson County, SD, resulted in 71,600 birds being affected. The next day in Charles Mix County, SD, 75,100 birds were affected by HPAI along with 50,500 more in Hamlin County.

South Dakota also reported more outbreaks over the Thanksgiving holiday weekend, which put the total affected birds in the United States above the previous HPAI record set in 2015.

As of Dec. 1, the latest numbers from APHIS show that 656 commercial and backyard flocks have been affected by HPAI in 46 states. To date, the virus has affected 52.7 million birds.

Maryland also reported HPAI cases in Washington County at a commercial table egg breeder flock which affected 24,600 birds.

The Maryland Department of Agriculture (MDA) announced that it quarantined the affected area, and birds on the properties were depopulated to prevent the spread of disease.

“MDA, USDA and other partner agencies are working diligently to address and localize the situation, including quarantining and testing nearby flocks,” said Joe Bartenfelder, agriculture secretary for Maryland.

A commercial upland gamebird producer in Grundy County, III., confirmed an outbreak of 8,000 birds on Nov. 30. This is the first commercial flock affected by the virus in the state this year.