title: Circulation of multiple genotypes of H1N2 viruses in a swine farm in Italy over a two-month period.
abstract: In August 2012 repeated respiratory outbreaks caused by swine influenza A virus (swIAV) were registered for a whole year in a breeding farm in northeast Italy that supplied piglets for fattening. The virus, initially characterized in the farm, was a reassortant Eurasian avian-like H1N1 (H1avN1) genotype, containing a haemagglutinin segment derived from the pandemic H1N1 (A(H1N1)pdm09) lineage. To control infection, a vaccination program using vaccines against the A(H1N1)pdm09, human-like H1N2 (H1huN2), human-like H3N2 (H3N2), and H1avN1 viruses was implemented in sows in November 2013. Vaccine efficacy was assessed by sampling nasal swabs for two months in 35-75 day-old piglets born from vaccinated sows. Complete genome sequencing of eight swIAV-positive nasal swabs collected longitudinally from piglets after the implementation of the vaccination program was conducted to investigate the virus characteristics. Over the two-month period, two different genotypes involving multiple reassortment events were detected. The unexpected circulation of multiple reassortant genotypes in such a short time highlights the complexity of the genetic diversity of swIAV and the need for a better surveillance plan, based on the combination of clinical signs, epidemiological data and whole genome characterization.
authors: Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, PD, Italy. Electronic address: msbeato@izsvenezie.it.
authors: Maria Serena
authors: MS
authors: Beato
authors: Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, PD, Italy.
authors: Luca
authors: L
authors: Tassoni
authors: Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, PD, Italy.
authors: Adelaide
authors: A
authors: Milani
authors: Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, PD, Italy.
authors: Annalisa
authors: A
authors: Salviato
authors: Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, PD, Italy.
authors: Guido
authors: G
authors: Di Martino
authors: Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, PD, Italy.
authors: Monica
authors: M
authors: Mion
authors: Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, PD, Italy.
authors: Lebana
authors: L
authors: Bonfanti
authors: Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, PD, Italy.
authors: Isabella
authors: I
authors: Monne
authors: Wellcome Trust Sanger Institute, Hinxton, UK.
authors: Simon James
authors: SJ
authors: Watson
authors: Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, PD, Italy.
authors: Alice
authors: A
authors: Fusaro
mesh_terms: D000818:Animals; D004196:Disease Outbreaks / Q000662:veterinary; D005838:Genotype; D057221:Influenza A Virus, H1N2 Subtype / Q000145:classification / Q000235:genetics*; D007558:Italy / Q000453:epidemiology; D009976:Orthomyxoviridae Infections / Q000453:epidemiology / Q000662:veterinary* / Q000821:virology; D010802:Phylogeny; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000821:virology*
keywords: H1N2; Italy; Swine influenza