Bird Flu in North America: What the USGS Does About It

Migratory waterfowl such as this northern pintail (Anas acuta) commonly carry avian influenza across North America and Asia; USGS research showed they help spread it between the two. Photograph by B. Guzetti, U.S. Geological Survey.

Background

Avian influenza viruses occur naturally in wild birds such as ducks, geese, swans and gulls, usually without making them ill. Spread to poultry, some become highly pathogenic, sickening and killing birds on backyard and commercial farms, causing devastating agricultural losses, and some strains can infect people directly. Mixed with mammal viruses, they can produce strains that pass from person to person, potentially starting a pandemic; every known pandemic flu virus has carried some genetic material of bird origin.

• Since 1996, one highly pathogenic avian influenza (HPAI) strain, H5N1, has infected wild birds, caused losses on poultry farms in Eurasia and North Africa, and killed several hundred people. Migratory birds likely helped it and other strains spread from China.
• In December 2014, HPAI was found in poultry in Canada and in migratory birds in the United States. It has since spread across much of the country, killing or forcing the culling of millions of domestic birds, and will likely keep spreading along migratory flyways and by other routes.
• These strains are not known to cause disease in people, though CDC advises caution in close contact with infected birds. Experts expect them to persist in North American wild birds for the next few years.

This unprecedented situation threatens the poultry industry, natural resource management and possibly human health. Science and decision tools are urgently needed to understand what keeps HPAI going in wild birds, forecast its spread, and spot new strains.

Why the USGS is involved

The USGS, the science agency of the Department of the Interior, has studied avian influenza since 2006 and belongs to the state and federal team that detects and responds to HPAI in North America. The Departments of Agriculture and the Interior work with other wildlife, agriculture and health agencies to help natural resource managers, agriculture officials and the poultry industry.

What USGS does

Scientists at several USGS centres study how migratory birds spread the virus, the genetics of viruses in wild birds, the water conditions that let the virus survive in wetlands, and the stages of infection in migratory birds. The USGS also offers diagnostics, surveillance and mathematical models that map the risk of spread between wild and domestic birds.

The USGS tests thousands of avian influenza samples every year from across the United States and neighbouring countries, to learn the virus's distribution, strain, evolution and ability to cause disease. USGS.

In December 2014 the USGS was instrumental in the first detection of HPAI in North American wild birds, through its wildlife health and diagnostic network. It has since expanded surveillance and shares what it learns about the types, spread and host species of HPAI through Wildlife Health Bulletins, the new online Wildlife Health Information Sharing Partnership – Event Reporting System (WHISPers) and scientific papers. With partners it wrote a national science strategy for HPAI, to forecast spread by wild birds, detect new strains, understand what lets the virus survive in the environment, and assess risks to poultry, natural resources and people.

Key findings since 2006

• Genetic evidence that wild birds carry avian influenza between continents.
• Rates and ranges of virus spread in Eurasia and North America, from satellite tracking, genetics and band recoveries.
• The risk HPAI poses to wild birds, from experimental infections.
• Genetics used to sharpen early-warning surveillance for viruses arriving from Asia, Europe and South America.
• Risk maps of transmission where poultry and wild birds meet.
• How avian influenza viruses behave in wetlands.

More

National Wildlife Health Center · Alaska Science Center · Patuxent Wildlife Research Center · Western Ecological Science Center · Avian influenza visualisation tool

Sources

• M. Camille Harris, A. Keith Miles, John M. Pearce, Diann J. Prosser, Jonathan M. Sleeman and Mary E. Whalen, USGS role and response to highly pathogenic avian influenza, U.S. Geological Survey Fact Sheet 2015–3059. https://pubs.usgs.gov/publication/fs20153059