First Isolation of the H₁N₂ Swine Influenza Virus in Polish Pig Farm

Abstract

The paper describes an outbreak of swine influenza, which was the first H1N2 outbreak confirmed in pig farm in Poland. The outbreak occurred in October 2011 in the farrows to finish farm, first in the fattening units, and subsequently in the reproduction and weaning sectors. Samples of the lungs taken from dead gilts were tested by the use of real time and multiplex PCR, sequencing, and virus isolation methods. The amplification of the genetic material extracted from the lungs confirmed the presence of the M1 gene sequence of type A influenza virus. Using multiplex PCR, the bands of 241 bp, typical for HA1 human-like type, and of 791 bp, typical for NA2, were demonstrated. The new isolates of swine influenza virus, named A/swine/Poland/15817/2011, were obtained in embryonated SPF chicken eggs and MDCK cells. Phylogenetic analysis of the HA and NA genes of the isolate revealed that the virus is of human swine linkage closely related to European human-like viruses. On the basis of such results, it can be stated that A/Swine/Poland/15817/2011 is a new swine influenza virus, representing the H1N2 subtype strain, which emerged in Poland.

C-reactive protein, haptoglobin, serum amyloid A and pig major acute phase protein response in pigs simultaneously infected with H1N1 swine influenza virus and Pasteurella multocida

“…Respiratory diseases in pigs are often considered as multifactorial problems caused by various pathogens (viral and bacterial) in combination. The most common infectious agent responsible for respiratory infection in pigs are: swine influenza virus (SIV), porcine reproductive and respiratory syndrome virus (PRRSV), Pasteurella multocida (Pm), Actinobacillus pleuropneumoniae, Mycoplasma hyopneumoniae [6,7]. These pathogens may act together to increase the severity and duration of the disease.…”

Postweaning mortality in commercial swine production II: review of infectious contributing factors

“…Morbidity estimates vary greatly but are of little value without consideration of other infectious agents. Morbidity estimates have been reported to increase by 2–100% when exposed to various IAV biotypes, and mortality has been reported to range from 1% to 10% ( Ma et al, 2010 ; Welsh et al, 2010 ; Markowska-Daniel et al, 2013 ). IAV is a common infectious agent providing a significant contribution to PRDC and subsequent mortality.…”

Influenza A viruses of avian origin circulating in pigs and other mammals.

“…Phylogenetic analysis revealed that Polish H1N2 is located in the phylogenetic tree in the clade of the human swine lineage marked as a group A (Kowalczyk et al, 2012). The highest nucleotide similarity of the HA1 Polish H1N1 virus with H1N2 strain was observed for A/Swine/Poland/01311/2009 (66.9%) (Markowska-Daniel et al, 2013b). An external gene of Polish H1N2 isolate indicates that it is most similar to a subgroup, which evolved at the beginning of 1990's and formed a new antigenic subcluster with the novel European and the Asian human influenza viruses and SIV isolates H1N2 and H3N2 from around year 2000 (Kowalczyk et al, 2012).…”