H5N5 virus transmission is driven by repeated cross-Atlantic introductions and transmission among high latitude seabirds
Abstract
In November 2025, the first global H5N5 infection was reported in a person in Washington State. Previously, these viruses had only been detected in seabirds and shorebirds near the Atlantic Ocean, suggesting potentially distinct ecology from dominant H5N1 strains. Using 354 global H5N5 genomes, we show that H5N5 viruses have been carried by high latitude seabirds and shorebirds across the Atlantic at least 9 times, with introductions more frequent in the fall and spring. We reconstruct a plausible path of cross-continental movement via Arctic or sub-Arctic regions, followed by a year of cryptic circulation prior to human spillover. These data show that H5N5 viruses have undergone far more intercontinental movements than previously recognized, and exhibit host and geographic patterns that are fundamentally distinct from dominant H5N1 lineages. The distinct host ecology, geography, and movement, paired with the capacity to infect a person, suggest that enhanced surveillance may be warranted.
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BibTeX
@misc{malekshahi2026h5n5,
title = {{H5N5 virus transmission is driven by repeated cross-Atlantic introductions and transmission among high latitude seabirds}},
author = {Clara R Malekshahi and Nicole St. Clair Knobloch and Alvin Crespo Bellido and Alexa Simulynas and Stephanie Goya and Leigh Papalambros and William J. Fitzsimmons and Alexander L. Greninger and Adam S. Lauring and Jonathan Runstadler and Martha I. Nelson and Wendy Puryear and Louise H. Moncla},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.29.762228},
url = {https://www.biorxiv.org/content/10.64898/2026.10.29.762228v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - H5N5 virus transmission is driven by repeated cross-Atlantic introductions and transmission among high latitude seabirds
AU - Clara R Malekshahi
AU - Nicole St. Clair Knobloch
AU - Alvin Crespo Bellido
AU - Alexa Simulynas
AU - Stephanie Goya
AU - Leigh Papalambros
AU - William J. Fitzsimmons
AU - Alexander L. Greninger
AU - Adam S. Lauring
AU - Jonathan Runstadler
AU - Martha I. Nelson
AU - Wendy Puryear
AU - Louise H. Moncla
PY - 2026
DA - 2026/10/29
PB - bioRxiv
DO - 10.64898/2026.10.29.762228
UR - https://www.biorxiv.org/content/10.64898/2026.10.29.762228v1
AB - In November 2025, the first global H5N5 infection was reported in a person in Washington State. Previously, these viruses had only been detected in seabirds and shorebirds near the Atlantic Ocean, suggesting potentially distinct ecology from dominant H5N1 strains. Using 354 global H5N5 genomes, we show that H5N5 viruses have been carried by high latitude seabirds and shorebirds across the Atlantic at least 9 times, with introductions more frequent in the fall and spring. We reconstruct a plausible path of cross-continental movement via Arctic or sub-Arctic regions, followed by a year of cryptic circulation prior to human spillover. These data show that H5N5 viruses have undergone far more intercontinental movements than previously recognized, and exhibit host and geographic patterns that are fundamentally distinct from dominant H5N1 lineages. The distinct host ecology, geography, and movement, paired with the capacity to infect a person, suggest that enhanced surveillance may be warranted.
SN - 2692-8205
ER -