DES MOINES, Iowa—The Iowa Department of Natural Resources (DNR) and its federal partners have been monitoring for the presence of highly pathogenic avian influenza (HPAI) in Iowa’s wild birds since early 2022. After nearly a year without detections in sick or dead birds, Iowa has seen a sharp jump in affected waterfowl across the state mostly, north of Interstate 80 since early December, spurred on by the stress of migration and the severe cold.
Avian influenza is a highly transmissible, naturally occurring virus found in certain waterfowl and shorebirds. There are various subtypes and strains, most of which cause limited harm to domestic poultry (low pathogenic) but some of which are lethal (highly pathogenic).
The H5N1 strain that has been circulating since 2022 is the first time HPAI has affected wild birds in North America at such a large scale.
“We’ve learned a lot about how this virus behaves in the intervening years. Dabbling ducks are a great indicator species, and we started seeing the number of HPAI detections in apparently healthy hunter harvests ramp up in mid-November. Just a couple weeks later we started responding to sick and dead geese,” said Dr. Rachel Ruden, state wildlife veterinarian with the Iowa DNR.
The U.S. Department of Agriculture has an online database tracking HPAI detections in wild birds and other species by state at https://www.aphis.usda.gov/livestock-poultry-disease/avian/avian-influenza/hpai-detections.
HPAI can also affect animals that consume infected carcasses, including other birds like eagles, and mammals, like red fox. Ruden said those who find five or more sick or dead flocking birds within a week should report their findings to their local wildlife biologist or state conservation officer. They are also interested in reports of solitary birds or mammals. Contact information is available online at www.iowadnr.gov under the About DNR tab on the homepage. (https://www.iowadnr.gov/Portals/idnr/uploads/contacts/wildlife_management.pdf) (https://www.iowadnr.gov/Portals/idnr/uploads/Law%20Enforcement/dnrlemap.pdf)
The virus can remain viable in a deceased bird for several weeks, depending upon environmental conditions.
“We are encouraging the public to stay away from sick birds, especially waterfowl. We have seen some shift in their clinical presentation – some are still developing the ‘classical’ signs like twisting their heads and necks or swimming in tight circles. However, some are just quiet and seem unable or unaware to fly away when approached,” said Dr. Ruden.
She also cautioned against bringing these birds to licensed wildlife rehabilitators to limit further spread.
At this point, she said, backyard birdfeeders are not of concern unless actively attended by waterfowl. Impact on upland birds, like wild turkeys, has also been rare given their behaviors and preferred habitats, which make them less likely to encounter the disease in the wild.
Waterfowl hunters can use these simple precautions to limit their exposure while field dressing and consuming wild game: https://www.aphis.usda.gov/sites/default/files/fsc_hpai_hunters.pdf. Cooking meat to an internal temperature of 165° F can kill the virus, if present.
While there is some inherent risk to hunting dogs given the nature of their interaction with carcasses, sick birds often become poor, uncoordinated flyers and so are less likely to be harvested. Hunters should prevent dogs from interacting with unknown carcasses, and avoid feeding them raw meat from harvested birds. More information is available online at https://www.ducks.org/conservation/waterfowl-research-science/waterfowl-hunters-and-the-avian-flu-what-you-need-to-know.
If poultry producers or those with backyard flocks suspect signs of H5N1 HPAI, they should contact their veterinarian immediately. Possible cases must also be reported to the Iowa Department of Agriculture and Land Stewardship at (515) 281-5305.
(contributed press release)
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