Reassortment in Pandemic (H1N1) 2009 Virus | CDC EID

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Volume 16, Number 11–November 2010
Dispatch
Reassortment of Ancient Neuraminidase and Recent Hemagglutinin in Pandemic (H1N1) 2009 Virus

Priyasma Bhoumik and Austin L. Hughes Comments to Author
Author affiliation: University of South Carolina, Columbia, South Carolina, USA

Suggested citation for this article

Abstract
Sequence analyses show that the outbreak of pandemic (H1N1) 2009 resulted from the spread of a recently derived hemagglutinin through a population of ancient and more diverse neuraminidase segments. This pattern implies reassortment and suggests that the novel form of hemagglutinin conferred a selective advantage.

Influenza virus A is a single-strand, negative-sense RNA virus whose genome consists of 8 RNA segments that encode 10 proteins (1). Influenza A is endemic in wild waterfowl, from which new strains periodically emerge to infect mammals, including humans and domestic pigs (2). Strains of influenza A viruses are categorized according to serotypes for hemagglutinin (HA) and neuraminidase (NA) proteins. These proteins cover the surface of the virus, are the main targets of the host's cellular immune response, and play major roles in the infection process (1,3,4).

In 2009, a novel strain of influenza A virus, pandemic (H1N1) 2009 virus, appeared in the human population, infecting thousands and causing many deaths (2,5–8). Phylogenetic analyses support a close relationship between the new strain and the strains that infect swine (6–9). Because different segments of the pandemic (H1N1) 2009 virus genome show different patterns of relationship to previously identified clades of influenza A virus sequences, these analyses support a role for intersegment reassortment in the origin of the new strain (6–9). For example, HA of pandemic (H1N1) 2009 virus shows a close relationship to that of classical swine influenza A virus, and NA shows a close relationship to that of Eurasian swine influenza A virus (6–9).

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Reassortment in Pandemic (H1N1) 2009 Virus | CDC EID

Suggested Citation for this Article

Bhoumik P, Hughes AL. Reassortment of ancient neuraminidase and recent hemagglutinin in pandemic (H1N1) 2009 virus. Emerg Infect Dis [serial on the Internet]. 2010 Nov [date cited].
http://www.cdc.gov/EID/content/16/11/1748.htm

DOI: 10.3201/eid1611.100361