USGS Says Alaska a Hot Spot for Avian Influenza to Enter North America
While no highly pathogenic avian influenza viruses have been found in Alaska, the state is an important area to monitor because of migratory bird flyways from North America and Eurasia that overlap it.
The U.S. Geological Survey has released additional evidence that western Alaska is still a hot spot for avian influenza to enter North America. The new report published in Virology Journal by BioMed Central said that, while no highly pathogenic avian influenza viruses have been found in Alaska, the state is an important area to monitor because of migratory bird flyways from North America and Eurasia that overlap it.
"Our past research in western Alaska has shown that while we have not detected the highly pathogenic avian influenza virus, up to 70 percent of the other avian influenza viruses isolated in this area were found to contain genetic material from Eurasia, providing evidence for high levels of intercontinental viral exchange," said Andy Ramey, a scientist with the USGS Alaska Science Center and lead author of the report. "This is because Asian and North American migratory flyways overlap in western Alaska."
According to the USGS April 5 news release, "most strains of avian influenza are not highly pathogenic and cause few signs of disease in infected wild birds. However, in poultry, some low-pathogenic strains can mutate into highly pathogenic avian influenza strains that cause contagious and severe illness or death among poultry, and sometimes among wild birds as well. Past research by the USGS found low pathogenic H9N2 viruses in an Emperor Goose and a Northern Pintail. Both viruses were nearly identical genetically to viruses found in wild bird samples from Lake Dongting, China, and Cheon-su Bay, South Korea."
The H9N2 viruses are not known to infect humans, but similar viruses have caused disease outbreaks in domestic poultry in Asia, Ramey said.
USGS scientists collaborated with colleagues at the Yukon Kuskokwim Health Corporation in Bethel, Alaska, and the Southeastern Cooperative Wildlife Disease Study in Athens, Georgia to obtain and test bird samples from Alaska Native subsistence hunters in Spring 2015. Hunters provided researchers with over 1,000 swabs from harvested water birds, which are the primary hosts of avian influenza viruses.