TUOLUMNE COUNTY, CALIF. — After reporting its first commercial broiler highly pathogenic avian influenza (HPAI) outbreak last week, California is seeing two more active cases.

Data from the Animal and Plant Health Inspection Service (APHIS) of the US Department of Agriculture found that 161,000 birds in a commercial broiler flock in Tuolumne County, Calif., were exposed to the virus. Another 34,800 birds were also the subject of an investigation in Fresno County.

About 33,900 birds were affected in the first case in Fresno. Infected locations remain under quarantine. 

The agency also noted that it recently detected HPAI in backyard flocks in various counties in California. Several other counties have found HPAI in wild birds. 

The latest numbers from the APHIS on Aug. 24 show 414 commercial and backyard flocks have been discovered with HPAI in 39 states. To date, the virus has affected 40.37 million birds.