By Charles R. Sharp, Former Wildlife Biologist
Avian influenza (AI) is a common generic term to describe a disease of birds. The term “avian flu” encompasses many viruses that are classified as having low pathogenicity (LP) or high pathogenicity (HP) based on the severity of the illness they cause in poultry.
In 2005-06, the Alabama Department of Conservation and Natural Resources Wildlife and Freshwater Fisheries (WFF) Division, a member of the Mississippi Flyway, joined the Atlantic, Central and the Pacific flyways and the U.S. Departments of Agriculture and Interior to develop a nationwide early detection plan. This plan includes sampling and testing for the highly pathogenic H5N1 avian influenza virus and other HPAI viruses to determine if any are in North American migratory birds. Waterfowl biologists, wildlife disease biologists, veterinarians and epidemiologists from the U.S. Departments of Agriculture, Interior and Health and Human Services, the International Association of Fish and Wildlife Agencies, and the National Association of Public Health Veterinarians developed the plan.
It was created in response to the possibility that wild migratory birds from North America may nest in the same parts of the northern breeding grounds as their counterparts from Asia. The possibility of interaction gives rise to the concerns that the HP H5N1 virus could be picked up by migratory birds on the breeding grounds and be carried back to the United States or Canada. Although not likely, biologists developed an early detection plan to increase the potential of discovering the virus before it has the opportunity to spread. This program involves collaboration among the U.S. Geological Survey, U.S. Fish and Wildlife Service, U.S. Department of Agriculture, state agencies (including Hawaii and U.S. Pacific Territories), and others.
Each of the national flyways developed an Avian Influenza Surveillance Plan including state quotas, budgets and reporting methods. These flyway plans were then used by each state in that flyway to develop their own step-down plan. To ensure continuity, an oversight committee made up of representatives from the federal agency involved in the survey is responsible for evaluation and modification of the plan as it is needed. The result is a coordinated and comprehensive interagency program that will provide an early warning to the agriculture, public health, and wildlife communities if migratory birds are found infected with HPAI
Alabama has just completed its 2007-08 Avian Influenza collections. In cooperation with Wildlife Services of the U.S. Department of Agriculture and WFF, personnel collected samples from 750 ducks, geese and other waterfowl including samples from hunter harvested birds, live birds trapped and released, and birds whose cause of death was uncertain. Species targeted for this year’s collection includes dabbling ducks such as mallards, teal, gadwall, Canada geese, and any species reported in a mortality event. These species have been determined to be the most likely birds to not only carry the H5N1 virus, but also those most likely to be resistant to the virus.
After collection, the data is entered into a national database and the biological samples are sent to Thompson Bishop Sparks State Diagnostic Lab at Auburn University to analyze. All labs use the same techniques to test for the presence of the virus. If a sample tests positive for the virus, that sample is forwarded to the National Wildlife Health Center in Madison, Wisconsin, where it is again tested to confirm or disprove a positive result. Results from the lab tests are then added to the national database and are included with the samples collected by cooperators in all parts of the United States.
The HP H5N1 avian influenza virus has not been detected in North America. The surveillance for the HP H5N1 virus is an ongoing survey, which will provide early detection of the avian influenza in future years.