House finch conjunctivitis is a chronic respiratory disease that affects wild and domestic avian species. The bacterium [Mg] causes house finch conjunctivitis in songbird species. In other birds, such as chickens and turkeys, this disease presents itself as infectious sinusitis. The disease was first found in domestic poultry in the early 1900s. It was not documented in wild species until the mid-1980s, when the disease was confirmed in Georgia's wild turkey population. In the mid-1990s, it was established in a population of house finches in the Mid-Atlantic. The strain in house finches was confirmed to be different than that of the wild turkey and domestic poultry. House finch conjunctivitis is now found throughout the East Coast, Midwest, and in some provinces of Canada.
Transmission
Transmission of house finch conjunctivitis results from direct contact with other infected individuals and the inhalation of contaminated aerosols. The disease can also persist on various surfaces, including birdfeeders. In wild turkeys, the disease can spread through direct contact, inhalation of contaminated aerosols, and transfer via eggs. Transmission can occur at any time of the year, but it is most common in the winter when birds flock to feeders.
Clinical Signs
The most common signs of infection in finches are crusty eyelids, swollen eyes, sinus drainage, and lethargy. In other birds, signs of infection are coughing, swollen sinuses, and swollen eyes.
Wildlife Management Implications
The introduction of house finch conjunctivitis has led to an overall decline in eastern house finch populations; although the Mid-Atlantic populations have not been affected. With help from the Audubon Society and Cornell Lab of Ornithology, scientists have been able to track declines through citizen science activities, including the Christmas Backyard Bird Count and feeder surveys.
Through these projects, other species, such as the American goldfinch and purple finch, have been confirmed to have the disease. Unlike the house finch, no general population declines have been reported in these species. To limit the spread of this disease in backyard birds, regularly clean out your birdfeeders and soak them in a 10% bleach solution for a minimum of 15 minutes.
Human Health Significance
House finch conjunctivitis is not known to impact human health.
Additional Resources
CDC Conjunctivitis in Wild Songbirds Article
Department of Environmental Conservation New York State House Finch Conjunctivitis