The Delaware Department of Agriculture (DDA) announced on Feb 11, 2025 that testing of a backyard flock in Sussex County, Del., has returned presumptive positive for H5 avian influenza from the University of Delaware’s Lasher Laboratory in Georgetown, part of the National Animal Health Laboratory Network. Additional samples have been sent to the U.S. Department of Agriculture’s National Veterinary Services Laboratory (NVSL) for further confirmation. This is the first case of H5 avian influenza in poultry in Sussex County.

State officials have quarantined the affected premises, and birds on the property have been depopulated to prevent the spread of the disease. Birds from the affected flock will not enter the food system.

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

During this time, DDA strongly encourages backyard flock owners to keep all birds in their coop and undercover, so they do not commingle with wild birds or come into contact with wild bird droppings contaminated with the virus.

All poultry producers and backyard flock owners should be monitoring flocks for any signs of increased mortality. Pay particular attention to whether birds show signs of respiratory illness or distress, such as sneezing, gasping for air, coughing, and/or runny nose. Other signs of HPAI in poultry can include swelling around the eyes, neck, and head; purple discoloration of the wattles, combs, and legs; tremors, drooping wings, circling, twisting of the head and neck, or any combination; watery, green diarrhea; lack of energy, poor appetite; and a drop in egg production, or soft or thin-shelled, misshapen eggs.

Backyard flock owners are required to register their flocks with the Delaware Department of Agriculture. This allows for timely information on disease incidents to be sent to all poultry producers. Backyard flock registration forms are available online at https://de.gov/poultry.