Understanding Avian Influenza Exposure and Antibodies in Understudied Species
Recent outbreaks of highly pathogenic avian influenza have impacted a dramatically wider range of bird hosts than ever before. USGS researchers are working to identify which bird species have been exposed, which have developed immune responses, and how these species may influence viral ecology to inform risk management activities.
What is the issue?
Although low pathogenic avian influenza viruses regularly occur in wild waterfowl and gulls, there has historically been limited evidence of avian influenza infection or virus antibodies reported from other waterbird species. Following the incursion of clade 2.3.4.4b Gs/GD highly pathogenic H5N1 into North America in 2021, increased mortality of wild birds has been reported, including from species not previously known to be affected by avian influenza virus.
What is at stake?
Of the 508 wild bird species recognized as impacted by highly pathogenic H5Nx viruses by Food and Agriculture Organization of the United Nations, 281 have been added since 2021. Within North America, organizations tasked with wildlife disease surveillance, including USGS and collaborators, have observed unprecedented disease impacts across waterbird species, particularly colonial nesting waterbirds. Scavenging and raptor species have also been affected by the latest avian influenza outbreak, including newly affected species like the federally endangered California Condor (Gymnogyps californianus).
What is our approach?
Current federal sampling regimes for avian influenza primarily address waterfowl, specifically dabbling ducks, which likely play the greatest role in viral transmission and dispersal. Thus, while the national surveillance strategy has proven effective at identifying when and where avian influenza viruses affect waterfowl, there is comparatively little sampling of other bird species. Additionally, our understanding of how highly pathogenic avian influenza impacts these understudied species has been generally limited to observations of mortalities or lab-based experiments, with relatively few efforts to identify prevalence and antibody response in wild bird populations.
This project focuses on sampling a wide array of waterbird and other understudied bird species for active infection with and antibodies to avian influenza to improve our understanding of the role these species may play in the persistence and spread of these viruses. USGS and partners are also working to use existing data demonstrating wild waterfowl abundance and viral prevalence to explore where additional bird species are most likely to be exposed to new strains of avian influenza virus. Previous findings with species such as Lesser Scaup (Aythya affinis) have already been used to revise sampling priorities for U.S. Department of Agriculture’s avian influenza surveillance.
What are the benefits?
A more comprehensive understanding of what broader avian species can serve as vectors of avian influenza viruses is important for informing transmission and persistence on the landscape, along with subsequent risk to commercial poultry operations. Similarly, knowing which bird species of conservation concern have been exposed and whether or not they have been able to mount an antibody response is a critical knowledge gap necessary to understand continued mortality risk within wild bird populations.
<<Back to Avian Influenza Research at EESC
Recent outbreaks of highly pathogenic avian influenza have impacted a dramatically wider range of bird hosts than ever before. USGS researchers are working to identify which bird species have been exposed, which have developed immune responses, and how these species may influence viral ecology to inform risk management activities.
What is the issue?
Although low pathogenic avian influenza viruses regularly occur in wild waterfowl and gulls, there has historically been limited evidence of avian influenza infection or virus antibodies reported from other waterbird species. Following the incursion of clade 2.3.4.4b Gs/GD highly pathogenic H5N1 into North America in 2021, increased mortality of wild birds has been reported, including from species not previously known to be affected by avian influenza virus.
What is at stake?
Of the 508 wild bird species recognized as impacted by highly pathogenic H5Nx viruses by Food and Agriculture Organization of the United Nations, 281 have been added since 2021. Within North America, organizations tasked with wildlife disease surveillance, including USGS and collaborators, have observed unprecedented disease impacts across waterbird species, particularly colonial nesting waterbirds. Scavenging and raptor species have also been affected by the latest avian influenza outbreak, including newly affected species like the federally endangered California Condor (Gymnogyps californianus).
What is our approach?
Current federal sampling regimes for avian influenza primarily address waterfowl, specifically dabbling ducks, which likely play the greatest role in viral transmission and dispersal. Thus, while the national surveillance strategy has proven effective at identifying when and where avian influenza viruses affect waterfowl, there is comparatively little sampling of other bird species. Additionally, our understanding of how highly pathogenic avian influenza impacts these understudied species has been generally limited to observations of mortalities or lab-based experiments, with relatively few efforts to identify prevalence and antibody response in wild bird populations.
This project focuses on sampling a wide array of waterbird and other understudied bird species for active infection with and antibodies to avian influenza to improve our understanding of the role these species may play in the persistence and spread of these viruses. USGS and partners are also working to use existing data demonstrating wild waterfowl abundance and viral prevalence to explore where additional bird species are most likely to be exposed to new strains of avian influenza virus. Previous findings with species such as Lesser Scaup (Aythya affinis) have already been used to revise sampling priorities for U.S. Department of Agriculture’s avian influenza surveillance.
What are the benefits?
A more comprehensive understanding of what broader avian species can serve as vectors of avian influenza viruses is important for informing transmission and persistence on the landscape, along with subsequent risk to commercial poultry operations. Similarly, knowing which bird species of conservation concern have been exposed and whether or not they have been able to mount an antibody response is a critical knowledge gap necessary to understand continued mortality risk within wild bird populations.