ANNAPOLIS, MD (January 30, 2025)— State laboratory testing has detected a case of highly pathogenic H5N1 avian influenza (HPAI) in a Montgomery County backyard flock. Maryland Department of Agriculture officials have quarantined all affected premises, and birds on the properties are being or have been depopulated to prevent the spread of the disease. Birds from the affected flock will not enter the food system.

Confirmation by the U.S. Department of Agriculture’s (USDA) National Veterinary Services Laboratory is pending with final results anticipated in the coming days.

Avian influenza is a highly contagious airborne respiratory virus that spreads easily among birds through nasal and eye secretions, as well as manure. The virus can be spread in various ways from flock to flock, including by wild birds, through contact with infected poultry, by equipment, and on the clothing and shoes of caretakers. This virus affects chickens, ducks, and turkeys, along with some wild bird species such as ducks, geese, shorebirds, and raptors.

Backyard flock owners are required to register their flocks with the Maryland Department of Agriculture to assist in protecting Maryland’s poultry industries from diseases such as HPAI.