About 40 backyard birds in Sacramento County test positive for avian flu

The U.S. Department of Agriculture announced that approximately 90 birds from two backyard flocks in Northern California tested positive for avian influenza in October, CBS News reported.

About 40 birds in a backyard flock located in Sacramento County were confirmed to have avian flu on October 5, while roughly 50 birds in a Solano County flock tested positive on October 20, according to the USDA.

Avian influenza, caused by influenza type A viruses, can vary in severity depending on the species and strain involved. Symptoms in birds may include coughing, sneezing, loss of appetite, purple discoloration of combs and legs, or sudden death without prior signs, the USDA explained.

Highly pathogenic strains of avian flu are the most dangerous and can quickly affect entire flocks, whereas low pathogenic strains often cause few or no symptoms but can become more severe in poultry.

The USDA also noted that avian influenza A viruses are not known to regularly infect people, reducing concerns about human transmission at this time.