title: A historical perspective of influenza A(H1N2) virus.
abstract: The emergence and transition to pandemic status of the influenza A(H1N1)A(H1N1)pdm09) virus in 2009 illustrated the potential for previously circulating human viruses to re-emerge in humans and cause a pandemic after decades of circulating among animals. Within a short time of the initial emergence of A(H1N1)pdm09 virus, novel reassortants were isolated from swine. In late 2011, a variant (v) H3N2 subtype was isolated from humans, and by 2012, the number of persons infected began to increase with limited person-to-person transmission. During 2012 in the United States, an A(H1N2)v virus was transmitted to humans from swine. During the same year, Australia recorded its first H1N2 subtype infection among swine. The A(H3N2)v and A(H1N2)v viruses contained the matrix protein from the A(H1N1)pdm09 virus, raising the possibility of increased transmissibility among humans and underscoring the potential for influenza pandemics of novel swine-origin viruses. We report on the differing histories of A(H1N2) viruses among humans and animals.
authors.forename: Naomi
authors.initials: N
authors.lastname: Komadina
authors.forename: Jodie
authors.initials: J
authors.lastname: McVernon
authors.forename: Robert
authors.initials: R
authors.lastname: Hall
authors.forename: Karin
authors.initials: K
authors.lastname: Leder
mesh_terms: D000818:Animals; D019143:Evolution, Molecular; D049673:History, 20th Century; D049674:History, 21st Century; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics / Q000302:isolation & purification; D057221:Influenza A Virus, H1N2 Subtype / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics / Q000302:isolation & purification; D009980:Influenza A virus; D007251:Influenza, Human / Q000453:epidemiology* / Q000266:history* / Q000635:transmission; D009976:Orthomyxoviridae Infections; D016865:Reassortant Viruses / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D013552:Swine
keywords: H1N2 subtype; Influenza A virus; influenza; pandemic; reassortant; swine; viruses; zoonoses