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National Wildlife Health Center

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Quarterly Wildlife Mortality Report
January 2015 to March 2015

Written and compiled by the U.S. Geological Survey National Wildlife Health Center Epidemiology Team members: Anne Ballmann, Barb Bodenstein, Bob Dusek, Dan Grear, and Jenny Chipault

Highly pathogenic avian influenza in North America – 2015 first quarter update
Highly pathogenic avian influenza (HPAI) virus was first detected in wild waterfowl in the United States during the investigation of an early December 2014 waterfowl mortality event, later attributed to aspergillosis, in Washington State (Pacific Flyway). Subsequent field and laboratory investigations, conducted by the USGS National Wildlife Health Center (NWHC), the U.S. Department of Agriculture (USDA), Washington Department of Fish and Wildlife, and the Washington Animal Disease Diagnostic Laboratory, identified three HPAI viruses (H5N8, H5N2, and H5N1) in wild birds in this region. As of the end of May 2015, these three HPAI strains have been detected in varying degrees in commercial poultry operations, backyard poultry operation, wild birds, and captive wild birds in the Pacific, Central, and Mississippi Migratory Bird Flyways.

Flyway Domestic Detection (No. farms)1 Wildlife Detection (No. birds)1
Pacific Backyard (8)
Commercial (2)
Highly Pathogenic Subtypes‡
EA H5N8 (3), EA/AM H5N2 (7)
Wild Duck (55)
Wild Goose (2)
Wild Raptor (5)
Captive Raptor (6)
Highly Pathogenic Subtypes‡
EA H5N8 (22), EA/AM H5N2 (27), EA/AM H5N1 (3), EA H5 (10)
Central Backyard (3)
Commercial (13)
Highly Pathogenic Subtypes‡
EA/AM H5N2 (16)
Wild Duck (1)
Wild Goose (2)
Highly Pathogenic Subtypes2
EA/AM H5N2 (2), EA H5 (1)
Mississippi Backyard (8)
Commercial (168)
Highly Pathogenic Subtypes2
EA H5N8 (1), EA/AM H5N2 (175)
Wild Duck (1)
Wild Goose (4)
Wild Raptor (2)
Captive Raptor (1)
Highly Pathogenic Subtypes2
EA/AM H5N2 (6), EA H5 (1)

1Data from USDA as of May 31, 2015, see www.usda.gov/avianinfluenz for details and up-to-date information

2EA = Contains genetic material from Eurasian strain only, EA/AM = Contains genetic material from both Eurasian and American strains, H5 = H5 icA assay identified Eurasian H5 clade with no viral isolation for further subtyping

There have been no reports of clinical disease in North American wild ducks attributable to these HPAI viruses. However, multiple HPAI-infected Canada geese (Branta canadensis) exhibited neurologic signs (head thrown back, jerky movements, and swimming in circles) shortly before death. The range and prevalence of severe neurological signs in HPAI-infected geese is not well characterized; please contact the NWHC or your State wildlife health official to report sick geese or other birds. These HPAI viruses are believed to be the primary or underlying cause of death in various raptor species including red-tailed hawk (Buteo jamaicensis), Cooper’s hawk (Accipiter cooperii), captive gyrfalcons (Falco rusticolus), peregrine falcon (F. peregrinus), captive great-horned owl (Bubo virginianus), bald eagle (Haliaeetus leucocephalus), and snowy owl (B. scandiacus).

The NWHC is continuing to monitor for HPAI by testing sick and dead migratory birds submitted for cause of death determination, and has expanded submission criteria to include single raptor mortalities, birds exhibiting neurological impairment, and birds with high relative risk of exposure based on proximity to infected domestic birds. During the first quarter of 2015, the NWHC accepted approximately 60% more avian submissions than during the first quarter of 2014, and has screened nearly 300 birds for HPAI through these diagnostic submissions. In addition, the NWHC has partnered with multiple state agencies to test over 1,200 hunter-harvested birds (waterfowl and turkey) for HPAI. The NWHC is also a partner in the Interagency Steering Committee for Surveillance for Highly Pathogenic Avian Influenza in Wild Birds.

To date, no humans or other mammals have shown signs of disease from these particular viruses but field personnel handling live or dead wild birds should take appropriate precautions. As we learn more about these HPAI viruses, submission and testing criteria may change; please consult with a field epidemiologist at the NWHC if you have any specific concerns. The NWHC will continue to provide updates via Wildlife Health Bulletins as more information becomes available.

White-nose syndrome winter 2014/2015 summary
Iowa joined the growing list of States and provinces with confirmed cases of white-nose syndrome (WNS) during the winter 2014/2015 surveillance season, bringing the current total to 26 States and 5 provinces. A combination of carcasses, non-lethal skin swabs, and/or environmental samples collected from 18 States and representing 99 bat hibernacula were evaluated by the USGS National Wildlife Health Center (NWHC) for Pseudogymnoascus destructans (Pd), the fungus that causes WNS. No further westward expansion of the disease was identified this past winter, although Pd now extends into eastern Oklahoma (Delaware County). At the time of this report, no updates on disease progression were available from Minnesota or Mississippi, which first identified Pd in Spring 2013 and 2014, respectively. Interestingly, 2014/2015 surveillance conducted in Rhode Island (within the WNS endemic area) failed to detect the presence of Pd. Winter surveys indicated that bat populations, although small, have remained stable there since surveys began in 2011. No new bat species were added to the list of those susceptible to WNS. Of the 14 cave hibernating species tested by the NWHC during winter 2014/2015 (including 6 western bat species) only little brown bats (Myotis lucifugus), Indiana bats (M. sodalis), tricolored bats (Perimyotis subflavus), and Northern long-eared bats (M. septentrionalis) tested positive for Pd.

A large winter bat mortality event involving approximately 2,000 little brown bats was investigated at an active mine complex in Pierce County, Wisconsin. Bronchopneumonia (for which the underlying cause was not identified) was consistently found among specimens examined at the NWHC; WNS was not detected in this event. Partners are reminded that the NWHC provides diagnostic and epidemiological assistance to investigate unusual bat mortality events throughout the year. Federal, State, or tribal agencies wishing to participate in the expanded national Pd surveillance strategy should contact Dr. Anne Ballmann (608-270-2445, aballmann@usgs.gov) to discuss options for their region.

Exposure of U.S. bald and golden eagles to contaminants
The USGS National Wildlife Health Center (NWHC), in collaboration with the USFWS Mountain Prairie Region 6 Environmental Contaminants Program, has initiated a study to evaluate opportunistically recovered bald (Haliaeetus leucocephalus) and golden (Aquila chrysaetos) eagle carcasses for cause of death determination, as well as to determine exposure to anticoagulant rodenticides, lead, and mercury. These contaminants were identified in 2014 as priorities for FWS Region 6. Our goal is to evaluate up to 140 eagle carcasses annually over the next two years from the Dakotas, Montana, Nebraska, Colorado, Kansas, Utah, and Wyoming for evidence of exposure to these contaminants. Data generated from this effort will expand upon the bald and golden eagle toxicant studies being performed in other FWS regions, and will also supplement on-going golden eagle assessments conducted by the USGS Snake River Field Station (Boise, Idaho). Based on the results of these studies, FWS will develop public outreach materials that describe exposure pathways and suggest alternatives to lead ammunition and anticoagulant rodenticides. In addition to our current focus on Region 6, the NWHC accepts any intact and freshly dead bald or golden eagles for cause of death determination from Federal, State, or tribal partners. Diagnostic data are shared with USFWS for management purposes and eagle carcasses deemed free of zoonotic disease are transferred to the National Eagle Repository for distribution to Native American tribal members.

To view, search, and download historic and ongoing wildlife morbidity and mortality event records nationwide visit the Wildlife Health Information Sharing Partnership event reporting system (WHISPers) online database: http://www.nwhc.usgs.gov/whispers/

To request diagnostic services or report wildlife mortality: http://www.nwhc.usgs.gov/services/

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