Abstract Title
Outbreak of highly pathogenic avian influenza H5N1 in California condors: emergency response and mitigation
Abstract
The U.S. federal government listed the California condor (Gymnogyps californianus; condor) as endangered in 1967 due to their rapidly declining population. Currently fewer than 350 condors are free flying in the wild. The ongoing effort to recover the condor is intensive and includes addressing numerous conservation threats to the species (predominantly lead poisoning), captive breeding, as well as bird release and monitoring at multiple field sites. On March 30, 2023, testing confirmed that a condor found dead in Arizona was positive for highly pathogenic avian influenza (HPAI) Eurasian strain H5N1 clade 2.3.4.4b. Twenty additional dead condors, and live birds exhibiting signs of illness, occurred in Arizona over the following month. The U.S. Fish and Wildlife Service established an incident command structure to facilitate the emergency response to mitigate the effects that HPAI might have on condor population recovery. The response included infrastructure and management changes to enhance biosecurity and biosafety at field sites, HPAI surveillance (both virus and antibody detection) of condor flocks, as well as an HPAI vaccination program for both captive and free flying condors. The outbreak occurred only in the Southwest condor flock, which ranges in Arizona and Utah; HPAI was not detected in the condor flock in California. Serology results indicate that a significant proportion of the Southwest condor flock was naturally exposed to HPAI H5N1 and survived infection. Condor mortalities due to HPAI ceased in mid-April of 2023.
Co-Author(s)
Samantha E. J. Gibbs, U.S. Fish and Wildlife Service; Ashleigh V. Blackford, U.S. Fish and Wildlife Service; Joanna C. Gilkeson, U.S. Fish and Wildlife Service; Jon Wallace, U.S. Fish and Wildlife Service; Steve Kirkland, U.S. Fish and Wildlife Service; Shaula Hedwall, U.S. Fish and Wildlife Service; Amanda E. Holland, U.S. Fish and Wildlife Service; Tim Hauck, The Peregrine Fund; Shawn Farry, The Peregrine Fund; Tabitha Viner, U.S. Fish and Wildlife Service; Rebecca Kagan, U.S. Fish and Wildlife Service; Gregory P. Nitzel, Zoetis, Inc; Stephanie Lamb, Liberty Wildlife; Rebecca Poulson, Southeastern Cooperative Wildlife Disease Study; Dave Stallknecht, Southeastern Cooperative Wildlife Disease Study; Mary I. Donahue, USDA APHIS Veterinary Services; Ariel Mixon, USDA APHIS Wildlife Services; Michelle L. Verant, National Park Service; Lisa A. Shender, National Park Service
Abstract Category
Notable outbreaks, field and molecular epidemiology, and surveillance in wild birds