Influenza A Virus in Penguins

It created a bit of surprise in some newspapers when scientists reported they had identified a novel avian Influenza Virus in a group of Adélie penguins (Pygoscelis adeliae) from two different sites on Antarctica. The virus, Influenza A(H11N2) Virus, was found to be unlike any other circulating avian Influenza[1]. Other genotypes of Influenza A(H11N2) Virus do circulate amongst migratory seabirds in the Americas[2] and domestic duck in China[3].

Distinct lineages of avian influenza viruses (AIVs) are harboured by spatially segregated birds, yet significant surveillance gaps exist around the globe. Virtually nothing is known from the Antarctic.
[Image: Thomas Pickard]
Their genetic segments were distinct from all known contemporary influenza viruses. Four of the gene segments were most closely related to North American avian lineage viruses from the 1960s to 1980s. Two other genes showed a distant relationship to a large number of South American avian Influenza viruses from Chile, Argentina and Brazil. The researchers estimated that the virus has been evolving for the past 49 to 80 years without anyone knowing about it. Whether this evolution has occurred exclusively in Antarctica is currently unknown.

Avian influenza viruses (AIVs) are typically maintained and spread by migratory birds, resulting in the existence of distinctly different viruses around the world. However, AIVs have not previously been detected in Antarctica. The study also showed that the genome diverged between 49 and 80 years ago from other AIVs, with several genes showing similarity and shared ancestry with equine Influenza(H3N8) viruses. This study provides the first insight into the ecology of AIVs in Antarctica and highlights the potential risk of an introduction of highly pathogenic AIVs into the continent.

The virus does not cause any visible illness in the penguins.

[1] Hurt et al: Detection of Evolutionarily Distinct Avian Influenza A Viruses in Antarctica in mBio - 2014
[2] Gonzáles-Reiche et al: Influenza a viruses from wild birds in Guatemala belong to the North American lineage in PLoS One - 2012
[3] Qui et al: Distribution of avian influenza virus subtypes among domestic ducks in eastern China in Wei Sheng Wu Xue Bao - 2008

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