Abstract Title
Possible Adélie penguin (Pygoscelis adeliae) die-off from avian cholera during incursion of high pathogenicity avian influenza into Antarctica, 2024
Abstract
High pathogenicity avian influenza (HPAI) viruses of the Goose/Guangdong lineage have been spreading worldwide since 1996, and viruses of the currently circulating 2.3.4.4b clade were first reported in mainland Antarctica in February 2024 in skuas (Stercorarius spp.). In order to investigate the spread and impact of this virus incursion, we visited sites along the Antarctic peninsula in March 2024. At the Danger Islands, which host two of the world’s largest Adélie penguin (Pygoscelis adeliae) colonies, we detected an unusual mortality event involving >1000 Adélie penguins dead among other dead seabirds. We examined 33 Adélie penguin carcasses and 16 carcasses from other species, and collected tissue samples and swabs for microbiological and pathological analyses. By RT-qPCR, we detected high DNA levels of Pasteurella multocida, the causative agent of avian cholera, in multiple tissues from 43 of 49 carcasses. Additionally, low RNA levels of HPAI virus were detected in tissues of Adélie penguins, skuas and sheathbills (Chionis albus) (results not shown here). In 7 of 8 Adélie penguins for which histopathology samples were collected, characteristic avian cholera lesions were detected, including hepatic and lung necrosis with intralesional coccoid bacterial aggregates. All 8 carcasses tested negative for HPAI virus antigen by immunohistochemistry. We concluded that avian cholera was the likely cause of this unusual mortality event of Adélie penguins, while HPAI was detected and might have also contributed to mortality. These results show the relevance of considering multiple causes of death when facing unusual mortality events, even in the concurrent presence of HPAI.
Co-Author(s)
Matteo Iervolino1a, Lineke Begeman1a, Anne Günther2, Theo M. Bestebroer1, Lonneke Leijten1, Dirk Höper2, Florencia Soto3, Antonio Alcamí4, Begoña Aguado4, Thijs Kuiken1, Martin Beer2, Timm Harder2, Peter van Run1, Ben Wallis5, Adam Coerper5, Alice Reade5, Meagan Dewar6b and Ralph E.T. Vanstreels7b
a Shared-first authors
b Shared-last authors
1 Department of Viroscience, Erasmus University Medical Center, the Netherlands
2 Institute of Diagnostic Virology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Germany
3 Instituto de Biología de Organismos Marinos (IBIOMAR-CONICET), Argentina
4 Centro de Biología Molecular Severo Ochoa, CSIC, Spain
5 Ocean Expeditions Support Vessel S/V Australis
6 Future Regions Research Centre, Federation University Australia
7 Karen C. Drayer Wildlife Health Center, One Health Institute, School of Veterinary Medicine, University of California - Davis, United States
Abstract Category
Notable outbreaks, field and molecular epidemiology, and surveillance in wild birds