Previously, EGG-NEWS reported that some species of wild birds are susceptible to H5N1 Avian Influenza virus showing clinical signs and in some cases extensive mortality. Deaths have occurred in cranes in Israel and India, cormorants in South Africa, geese in Scotland, swans in European nations, gulls in Newfoundland and in crows and raptors in various nations in Europe and Asia.

Recently, H5N1 virus was isolated from clinically affected wild waterfowl in the U.S., although the majority of migratory duck species appear to be refractory to the infection.

During the past week, there was evidence of infection in American white pelicans in Pettis, Randolph and St. Charles counties in Missouri.  Wildlife biologists in North Carolina have identified the virus in affected red headed ducks in Carteret, Dare, Hyde and Wake counties all showing neurologic signs.  The virus has also been identified in free-living ducks found dead in Martin County, Florida.

From an epidemiologic perspective, clinically affected birds generally die rapidly, but unaffected shedders serve to disseminate virus and are therefore a greater risk to commercial poultry.