Officials still do not know what has been causing the deaths of diseased birds in the eastern panhandle of West Virginia and throughout the mid-Atlantic region, but they are working to find an answer.
According to information provided by the West Virginia Division of Natural Resources (WVDNR), reports of affected birds have tapered off since late July.
Beginning in May, widespread reports of diseased birds started coming into multiple wildlife management agencies prompting them to take action. Birds were experiencing symptoms of eye swelling and crusty discharge and neurological signs of illness such as behavioral abnormalities.
Ethan Barton, Romney-based wildlife disease specialist for the WVDNR, told the West Virginia Daily News at that time that cases in West Virginia were following the same trends as witnessed in other states. Almost all of the cases were seen in juvenile birds with Common Grackles, European Starlings, Blue Jays and American Robin species most frequently reported.
Barton stated that the disease outbreak was most likely multifactorial, with a major cause of illness in juvenile birds being that they do not have fully-developed immune systems.
The most recent studies have found that 15-20% of the reports are related to lesions of the birds’ eyes. Mortality events most often involved one to four birds at a given location.
The WVDNR has noted that no human health or domestic livestock and poultry issues have been reported.
The following pathogens have not been detected in any tested birds: Salmonella and Chlamydia (bacterial pathogens), avian influenza virus, West Nile virus and other flaviviruses, Newcastle disease virus and other paramyxoviruses, herpesviruses and poxviruses and Trichomonas parasites.
Transmission electron microscopy and additional diagnostic tests, including microbiology, virology, parasitology and toxicology are ongoing, according to a WVDNR press release. However, similar to previous avian disease outbreaks, where birds presented with swollen and crusted eyes, a species of bacteria called Mycoplasma was found in some sampled birds.
WVDNR officials continue to advise that folks in Jefferson and Berkeley counties cease feeding birds. Residents in other West Virginia counties may continue to feed birds, but should take the opportunity to take down, repair and disinfect their feeders.
For those who witness sick or dead birds near their feeder or bird bath, it is advisable to remove the feeder or bath for a period of two weeks and to sterilize with a 10 percent bleach solution. Residents may continue feeding hummingbirds but should clean feeders with soap and water and ensure hummingbird food is fresh every few days.
WVDNR, the Virginia Department of Wildlife Resources, District of Columbia Department of Energy and Environment, Maryland Department of Natural Resources, National Park Service and other agencies are continuing to work in partnership with diagnostic laboratories to investigate the cause of mortality. Those laboratories include the USGS National Wildlife Health Center, SCWDS, the University of Pennsylvania Wildlife Futures Program and the Indiana Animal Disease Diagnostic Laboratory.