Abstract Title
Wide-spread circulation and species-specific responses to HPAI in a Subantarctic wild bird community
Abstract
Seabirds, which breed in dense colonies in which viruses can quickly spread, have been particularly affected by the recent highly pathogenic avian influenza (HPAI) panzootic. In October 2023, the virus reached Subantarctica. Subsequently, several HPAI outbreaks, mostly affecting penguins and albatrosses, were reported in the Falkland Islands. In parallel with intense mortality event surveillance, systematic sampling of both dead and live birds from 14 species allowed us to obtain new insights on the mechanisms driving HPAI transmission in seabird communities.
Immunological data suggest an earlier introduction and wider transmission than graspable with symptomatic case detection only, highlighting the potential importance of asymptomatic carriers. This was then confirmed by viral RNA direction in 7 species, including 4 species for which no unusual mortality event had been reported. Together, these data revealed that apex scavengers can survive infection and acquire immunity against the virus. On the contrary, meso-predators like penguins and albatrosses likely remain infected a few days and die before developing any immunity. Viral sequences suggest several introduction events from South America, followed by intense cross-species transmission, notably between preys and predators, but low probability of outbreak initiation, all together pointing towards at-sea scavenging as a key spread mechanism.
This study highlights the need for systematic sampling of both live and dead animals, and affected and (apparently) non affected species to better understand HPAI dynamics. It also showcases successful community-led wildlife health monitoring and collaborative research on wildlife disease, involving local populations, local governmental and non-governmental organizations, and international research teams.
Immunological data suggest an earlier introduction and wider transmission than graspable with symptomatic case detection only, highlighting the potential importance of asymptomatic carriers. This was then confirmed by viral RNA direction in 7 species, including 4 species for which no unusual mortality event had been reported. Together, these data revealed that apex scavengers can survive infection and acquire immunity against the virus. On the contrary, meso-predators like penguins and albatrosses likely remain infected a few days and die before developing any immunity. Viral sequences suggest several introduction events from South America, followed by intense cross-species transmission, notably between preys and predators, but low probability of outbreak initiation, all together pointing towards at-sea scavenging as a key spread mechanism.
This study highlights the need for systematic sampling of both live and dead animals, and affected and (apparently) non affected species to better understand HPAI dynamics. It also showcases successful community-led wildlife health monitoring and collaborative research on wildlife disease, involving local populations, local governmental and non-governmental organizations, and international research teams.
Co-Author(s)
Augustin Clessin 1, Julia Emerit 2, Mathilde Lejeune 1, Francois-Xavier Briand 3, Dina M. Alter 2, Beatrice Grasland 3, Thierry Boulinier 1, Amanda Kuepfer 4, Zoe Fowler 5, Amandine Gamble 1
1 Centre d’Ecologie Fonctionnelle et Evolutive, UMR 5175, Université Montpellier, CNRS, EPHE, IRD, Montpellier, France
2 Department of Public & Ecosystem Health, Cornell University, Ithaca, United States
3 Anses - French Agency for Food, Environmental and Occupational Health Safety, Ploufragan-Plouzané Laboratory, Avian and Rabbit Virology, Immunology, and Parasitology Unit, Ploufragan, France
4 Falklands Conservation, Stanley, Falkland Islands
5 Falkland Islands Government, Stanley, Falkland Islands
Abstract Category
Notable outbreaks, field and molecular epidemiology, and surveillance in wild birds