Cross-species and mammal-to-mammal transmission of clade 2.3.4.4b highly pathogenic avian influenza A/H5N1 with PB2 adaptations
Highly pathogenic H5N1 avian influenza viruses (HPAIV) belonging to lineage 2.3.4.4b emerged in Chile in December 2022, leading to mass mortality events in wild birds, poultry, and marine mammals and one human case. We detected HPAIV in 7,33% (714/9745) of cases between December 2022-April 2023 and sequenced 177 H5N1 virus genomes from poultry, marine mammals, a human, and wild birds spanning >3800 km of Chilean coastline. Chilean viruses were closely related to Peru's H5N1 outbreak, consistent with north-to-south spread down the Pacific coastline. One human virus and nine marine mammal viruses in Chile had the rare PB2 D701N mammalian-adaptation mutation and clustered phylogenetically despite being sampled 5 weeks and hundreds of kilometers apart. These viruses shared additional genetic signatures, including another mammalian PB2 adaptation (Q591K, n = 6), synonymous mutations, and minor variants. Several mutations were detected months later in sealions in the Atlantic coast, indicating that the pinniped outbreaks on the west and east coasts of South America are genetically linked. These data support sustained mammal-to-mammal transmission of HPAIV in marine mammals over thousands of kilometers of Chile's Pacific coastline, which subsequently continued through the Atlantic coastline.
Authors
- Naomi Ariyama (ORCID: https://orcid.org/0000-0002-4713-5979)
- Carolina Aguayo
- Mauricio Ulloa (ORCID: https://orcid.org/0000-0002-3358-8889)
- Á. González (ORCID: https://orcid.org/0000-0001-7453-0360)
- Martha I. Nelson (ORCID: https://orcid.org/0000-0003-4814-0179)
- Christian Mathieu
- Hugo Araya
- R.G. Suárez López de Vergara
- Andrés Castillo (ORCID: https://orcid.org/0000-0001-9644-3719)
- Jorge Fernández (ORCID: https://orcid.org/0000-0002-5792-0719)
- Magdalena Johow
- Víctor Neira (ORCID: https://orcid.org/0000-0001-9062-9969)
- Catalina Pardo‐Roa (ORCID: https://orcid.org/0000-0002-5409-225X)
- C. Navarro (ORCID: https://orcid.org/0000-0002-7418-9411)
- Rafael Medina (ORCID: https://orcid.org/0000-0002-5013-6884)
- Harm van Bakel (ORCID: https://orcid.org/0000-0002-1376-6916)
- Ana S. Gonzalez‐Reiche (ORCID: https://orcid.org/0000-0003-3583-4497)
- Paulo C. Covarrubias
- Gabriela Muñoz (ORCID: https://orcid.org/0000-0002-9915-7555)
- Claudia Ávila
- Rodrigo Fasce (ORCID: https://orcid.org/0000-0002-2213-1461)
- Leonardo I. Almonacid (ORCID: https://orcid.org/0000-0002-7919-4826)
- Patricia Bustos (ORCID: https://orcid.org/0000-0001-8674-6142)
- Pablo N. Castillo-Torres
- Carmen Gloria González (ORCID: https://orcid.org/0000-0002-5793-7107)
- Rodolfo Reyes
- Juan Carlos Torres
Institutions
- Universidad de Las Palmas de Gran Canaria (ES)
- National Institutes of Health (US)
- Emory Healthcare (US)
- Emory University (US)
- Pontificia Universidad Católica de Chile (CL)
- Emory and Henry College (US)
- Instituto de Salud Pública de Chile (CL)
- Agriaquaculture Nutritional Genomic Center (CL)
- National Center for Biotechnology Information (US)
- National Influenza Center (MN)
- Gobierno de Chile (CL)
- University of Chile (CL)
- Icahn School of Medicine at Mount Sinai (US)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-03-06
- DOI
- https://doi.org/10.1038/s41467-025-57338-z
- Citations
- 50
- Primary Topic
- Influenza Virus Research Studies
- Type
- article
- Field-Weighted Citation Impact
- 67.71
Funders
- Division of Intramural Research, National Institute of Allergy and Infectious Diseases