The USGS is investigating a mysterious illness that has resulted in numerous reports of sick or dying birds with crusty swollen eyes (even blindness) and neurological effects such as tremors, inability to stand, and lethargy. The majority of affected birds are juvenile. The illness is rather widespread with reports of sick birds in Washington DC, Maryland, Virginia, West Virginia, Kentucky, Delaware, New Jersey, Pennsylvania, Ohio, and Indiana. Since May, diagnostic laboratories have been racing to identify the disease but have not had any luck. So fat, they have not found evidence of Salmonella, Chlamydia, flaviviruses such as avian influenza or West Nile, paramyxoviruses such as Newcastle disease, herpesvirus, poxvirus, or Trichomonas parasites. While a lot (but not all) of the affected birds tested positive for the bacteria mycoplasma, which is known to cause eye swelling, a lot of healthy birds that were included as controls tested positive as well.
Some states are continuing to ask people to take down bird feeders and stop filling water baths as these can spread the pathogen. They additionally recommend cleaning bird feeders and bird baths with a 10% bleach solution. If you do spot a sick or dead bird that may be infected, you are asked to call your state or district wildlife conservation agency to help them track the illness.