Abstract
Clade 2.3.4.4b H5 high pathogenicity avian influenza (HPAI) viruses arrived to North America in November 2021, later spreading to Central and South America. We compiled data from the World Animal Health Information System (WAHIS), Global Initiative on Sharing All Influenza Data (GISAID) and several public sources on HPAI detection and mortality in wildlife in the Americas from November 2021 to November 2023 (inclusive). As of July 2024, WAHIS data indicated 23,280 wild birds and 3,165 wild mammals affected in association with HPAI outbreaks during the period. In contrast, our compiled dataset suggests 680,000 wild birds and 57,000 wild mammals may have died during HPAI outbreaks. This vast discrepancy may stem from differences in surveillance and reporting strategies among countries. Due to its economic and public health significance, in most countries only the national veterinary authority (NVA) is allowed to collect and test animal samples for HPAI; however, NVAs often focus their limited resources and laboratory capacity on poultry surveillance, neglecting wildlife surveillance. Another limitation is that while some countries incorporate comprehensive estimates of wildlife mortality in WAHIS, others only report on carcasses personally witnessed by NVA officers. Availability of genomic data is also heavily skewed: although Canada and USA only accounted for 11% of potentially affected wildlife (<2% of wild mammals), they account for 96% of whole genomes from wildlife in GISAID (88% of wild mammals). Such discrepancies render public databases such as WAHIS and GISAID potentially unreliable to understand the epidemiology, evolution and conservation impacts of HPAI in wildlife.
Co-Author(s)
Ralph E. T. Vanstreels, Marcela M. Uhart
Karen C. Drayer Wildlife Health Center, One Health Institute, University of California - Davis
Abstract Category
Mortality estimations, impacts on harvest, conservation considerations, and potential mitigation strategies in wild birds