How do scientists study avian influenza in wild birds?
To learn more about the impacts of avian influenza on wild birds and the role wild birds may play in the spread of the virus, experts from government agencies have gathered samples from hundreds of thousands of live-captured, apparently healthy wild birds; hunter-harvested birds; and dead wild birds of all species.
Testing methods include analyses of fecal samples and swabs of the bird’s trachea, oropharynx, or cloaca. Tissues can be collected from dead birds.
The majority of the live bird and hunter-harvested avian influenza surveillance programs in the U.S. were discontinued in 2010. The USGS National Wildlife Health Center is focusing on testing sick and dead migratory birds, particularly ducks, geese and swans. This will facilitate early detection, situational awareness, and appropriate response to these viruses.
Due to the global threat to health and human safety posed by avian influenza monitoring has been conducted in the United States to determine the prevalence of such viruses in our wild waterfowl.
Ducks in North America can be carriers of avian influenza viruses similar to those found in a 2016 outbreak in Indiana that led to the losses of hundreds of thousands of chickens and turkeys, according to a recent study.
Some media are reporting that the Asian H5N1 strain of highly pathogenic avian influenza has now entered the United States. This is incorrect.
The North Atlantic region is a newly discovered important pathway for avian influenza to move between Europe and North America, according to a U.S. Geological Survey report published today.
Biological science aid, Marlee Malmborg, examines and records the viability of pallid sturgeon eggs at the Columbia Environmental Research Center.
Potential spread of highly pathogenic H5N1 strains by wild migratory ducks. H5N1 strains isolated from outbreaks in South Korea, Russia, and Japan from April to May 2008 were closely related to each other and to strains isolated from Dongting Lake in March 2008 from domestic chickens, ducks, and water. (Cappelle et al. 2014, EcoHealth).
Avian Influenza Transmission Risk Model Web Application -- Screen shot of an interactive web application that provides visualizations of avian influenza virus risk factors and models at the interface of wild and domestic birds. - A virtual tour was produced to familiarize users with the capabilities of the application.
Digitally-colorized negative-stained transmission electron micrograph of avian influenza viruses. Credit CDC/F.A. Murphy
The Avian Influenza Transmission Risk Model web application depicts the intricate connections between 16 layers of administrative, environmental, and economic data in an application that runs inside a web browser. To view and manipulate the full web application, please visit http://www.pwrc.usgs.gov/ai. The full web application requires a web browser with a large amount of memory available. This video gives an overview of the application and shows some of the features.
For more information on avian influenza, see http://www.pwrc.usgs.gov/ai. Two currently circulating avian influenza viruses, highly pathogenic A(H5N1) and low pathogenic A(H7N9) (hereafter H5N1 and H7N9) are of particular concern due to their high case-fatality rates (approximately 60 and 30% currently), and economic impact to the livestock industry and public health system. H5N1 first emerged in domestic geese in southern China in 1996 (12), and has since infected 60 countries across Asia, Africa, and Europe killing 374 people. This video provides an overview of the outbreaks, using data from the United Nations Food and Agriculture (UNFAO) database.
A biological technician of the USGS National Wildlife Health Center tests chicken eggs inoculated with a field sample from wild birds to detect the presence of avian influenza virus.
Blue-winged teal in Texas. Inset shows avian influenza virus
Scientists prepare to release Forster's Tern chicks following sampling for avian influenza study.
USGS scientist Dede Goldberg swabs a pintail duck for avian influenza at Monte Vista National Wildlife Refuge in Colorado.