Journal article
Influenza A virus infection dynamics in swine farms in Belgium, France, Italy and Spain, 2006-2008
Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.1
Anses, laboratoire de Ploufragan-Plouzané, France.2
Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Parma, Italy.3
Laboratorios HIPRA SA, Girona, Spain.4
Central Veterinary Institute of Wageningen UR, Lelystad, The Netherlands.5
Laboratory of Virology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium. Electronic address: Kristien.VanReeth@Ugent.be.6
Avian-like H1N1 and reassortant H3N2 and H1N2 influenza A viruses with a human-like haemagglutinin have been co-circulating in swine in Europe for more than a decade. We aimed to examine the infection dynamics of the three swine influenza virus (SIV) lineages at the farm level, and to identify possible regional and seasonal variations in their circulation.
Sera were collected from six successive generations of fattening pigs (2006-2008) in a total 80 farrow-to-finish herds in Belgium, Italy, France and Spain and examined for antibodies against the three SIVs in haemagglutination inhibition tests. Overall, in all regions and periods, 9.7% of all farms were negative for SIV, 49% were infected with one subtype, 38% with two subtypes and 3.9% with all three SIVs.
We found serological evidence for the circulation of all three subtypes in Belgium, Italy and Spain, while only infections with H1N1 and H1N2 SIVs were detected in France. Despite temporary changes in the circulation of H1N2 in Belgium and in Spain, there was no true seasonal variation. The exact combination of subtypes on the same farm differed in each of the sampling periods.
On the other hand, 21 farms were found to be consistently infected with the same SIV subtype throughout the study. This can either be explained by the persistence of the virus in a farm, or by the periodical re-introduction of SIVs of the same subtype.
Language: | English |
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Year: | 2013 |
Pages: | 543-550 |
ISSN: | 03781135 and 18732542 |
Types: | Journal article |
DOI: | 10.1016/j.vetmic.2012.11.014 |
Animals Europe European Surveillance Network for Influenza in Pigs (ESNIP) Fattening pigs Hemagglutination Inhibition Tests Infection dynamics Influenza A Virus, H1N1 Subtype Influenza A Virus, H1N2 Subtype Influenza A Virus, H3N2 Subtype Influenza A virus Orthomyxoviridae Infections Seasons Serological surveillance Sus scrofa Swine Swine Diseases Swine influenza