2016 Maine: Heads-up! Avian Flu Still a Threat in the US

By Anne Lichtenwalner, DVM, PhD, University of Maine Cooperative Extension

chickens in barnWinter weather has finally arrived in Maine. Most of us probably have our poultry flocks indoors right now, so we might think that the threat of disease from wild birds is minimal. For now, we still don’t have any poultry cases of avian influenza in our region. However, the state of Indiana has not been so fortunate.

A strain of highly pathogenic avian influenza (HPAI), H7N8, was found on a turkey farm there last week. This strain is different from the strain that caused extensive losses in 2015, and is thought to have arisen from North American strains of the flu. According to the USDA, “This new ‘homegrown’ strain was first found in the highly pathogenic form on a large turkey farm in Dubois County, Indiana on Friday. Around 60,000 birds were immediately depopulated at the site.”

Subsequent rapid responses by the USDA APHIS, along with state agents, have screened and depopulated additional flocks in a control zone, with the goal of containment of the virus. These efforts included identifying backyard flocks in the region. About 900 sites within the control zone were investigated; only fewer than 30 had backyard chickens. These have all been tested and results are pending, but so far, none have been depopulated. However, a large layer chicken facility near the turkey flock was depopulated to help prevent spread of HPAI. There were 9 additional turkey farms in the area that tested positive for avian influenza, but the virus turned out to be a “low pathogenicity” strain (LPAI). Nevertheless, over 400,000 birds were depopulated to keep the virulent strain of HPAI from spreading. The USDA responses were swift, decisive, and so far, successful.

What does this mean for Maine farmers?

No real changes in recommendations: keep your biosecurity efforts up, even though it’s winter. Even though this strain, like the earlier strain of HPAI, seems to affect turkeys primarily, there is no guarantee that any species or type of bird is immune. We have strains of LPAI in wild birds throughout the US, and mutation of these strains into virulent HPAI is possible. Though we were not affected last year, we should be vigilant.

Keep your birds physically separate from wild birds, and from feed, water or pasture visited by wild birds. The wild species considered most likely to carry risk of HPAI are the “dabbling” ducks, but there is no guarantee that any species is free of AI. Please see earlier posts to assess relative risks of transmission of the virus.

Recent work on the risk of AI spread via feeds produced using grains that may have been harvested in AI-contaminated grain fields suggested that the risks of feed-transmitted AI are low. Pelleted feeds were considered to carry an even lower risk than was “mash” type feed. The highest risks are either contact (personnel, equipment, birds) with infected flocks, or direct contact with wild birds. Following basic poultry biosecurity works as protection against most poultry diseases. Help us keep HPAI and other poultry diseases out of your, and your neighbors’, flocks.