Browsing by Author "Nelson, Martha I."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Cross-species and mammal-to-mammal transmission of clade 2.3.4.4b highly pathogenic avian influenza A/H5N1 with PB2 adaptations
    (2025) Pardo Roa, Catalina; Nelson, Martha I.; Ariyama, Naomi; Aguayo, Carolina; Almonacid Cárdenas, Leonardo Iván; Gonzalez-Reiche, Ana S.; Muñoz, Gabriela; Ulloa, Mauricio; Avila, Claudia; Navarro, Carlos; Reyes, Rodolfo; Castillo Torres, Pablo Nicolás; Mathieu, Christian; Vergara, Ricardo; Gonzalez, Alvaro; Gonzalez, Carmen Gloria; Araya, Hugo; Castillo, Andres; Torres, Juan Carlos; Covarrubias, Paulo; Bustos, Patricia; van Bakel, Harm; Fernandez, Jorge; Fasce, Rodrigo A.; Johow, Magdalena; Neira, Victor; Medina, Rafael
    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.
  • Thumbnail Image
    Item
    Cross-species and mammal-to-mammal transmission of clade 2.3.4.4b highly pathogenic avian influenza A/H5N1 with PB2 adaptations
    (2025) Pardo Roa, Catalina; Nelson, Martha I.; Ariyama, Naomi; Aguayo, Carolina; Almonacid Cárdenas, Leonardo Iván; Gonzalez-Reiche, Ana S.; Muñoz, Gabriela; Ulloa, Mauricio; Avila, Claudia; Navarro, Carlos; Reyes, Rodolfo; Castillo Torres, Pablo Nicolás; Mathieu, Christian; Vergara, Ricardo; Gonzalez, Alvaro; Gonzalez, Carmen Gloria; Araya, Hugo; Castillo, Andres; Torres, Juan Carlos; Covarrubias, Paulo; Bustos, Patricia; van Bakel, Harm; Fernandez, Jorge; Fasce, Rodrigo A.; Johow, Magdalena; Neira, Victor; Medina, Rafael
    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.
  • Thumbnail Image
    Item
    Cross-species transmission and PB2 mammalian adaptations of highly pathogenic avian influenza A/H5N1 viruses in Chile
    (2023) Pardo Roa, Catalina; Nelson, Martha I.; Ariyama, Naomi; Aguayo, Carolina; Almonacid Cárdenas, Leonardo Iván; Muñoz, Gabriela; Navarro, Carlos; Ávila, Claudia; Ulloa, Mauricio; Reyes, Rodolfo; Fuentes Luppichini, Eugenia Lucía Angélica; Mathieu, Christian; Vergara, Ricardo; González, Álvaro; González, Carmen Gloria; Araya, Hugo; Fernández, Jorge; Fasce, Rodrigo; Johow, Magdalena; Medina, Rafael; Neira, Víctor
    H5N1 highly pathogenic avian influenza viruses (HPAIV) emerged in wild birds in Chile in December 2022 and spilled over into poultry, marine mammals, and one human. Between December 9, 2022 – March 14, 2023, a coordinated government/academic response detected HPAIV by real-time RT-PCR in 8.5% (412/4735) of samples from 23 avian and 3 mammal orders. Whole-genome sequences obtained from 77 birds and 8 marine mammals revealed that all Chilean H5N1 viruses belong to lineage 2.3.4.4b and cluster monophyletically with viruses from Peru, indicating a single introduction from North America into Peru/Chile. Mammalian adaptations were identified in the PB2 segment: D701N in two sea lions, one human, and one shorebird, and Q591K in the human and one sea lion. Minor variant analysis revealed that D701N was present in 52.9 – 70.9% of sequence reads, indicating the presence of both genotypes within hosts. Further surveillance of spillover events is warranted to assess the emergence and potential onward transmission of mammalian adapted H5N1 HPAIV in South America.