Abstract
Swine influenza is one of the important zoonotic diseases of pigs. We conducted a longitudinal survey of swine influenza A viruses (S-IAV) circulating in a pig farm with history of endemic S-IAV infection from 2017 to 2018. The samples were collected from 436 pigs including nasal swab samples (n = 436) and blood samples (n = 436). Our result showed that 18.81% (82/436) were positive for influenza A virus and subsequently 57 S-IAV could be isolated. Then 24 out of 57 S-IAVs were selected for whole genome sequencing and could be subtyped as S-IAV-H1N1 (n = 18) and S-IAV-H3N2 (n = 6). Of 24 S-IAVs, we observed 3 genotypes of S-IAVs including rH1N1 (pdm + 1), rH1N1 (pdm + 2), and rH3N2 (pdm + 2). Since all genotypes of S-IAVs in this study contained internal genes from pdmH1N1-2009, it could be speculated that pdmH1N1-2009 was introduced in a pig farm and then multiple reassorted with endemic S-IAVs to generate diversify S-IAV genotypes. Our study supported and added the evidences that pdmH1N1-2009 and it reassortant have predominately persisted in pig population in Thailand. Thus, monitoring of S-IAVs in pigs, farm workers and veterinarians in pig farms is important and should be routinely conducted.
Highlights
Swine influenza is one of the important zoonotic diseases of pigs
The possible explanation is that this study was more focusing on target sample collection in piglets and weaning pigs (4–10 week-old), higher prevalence of swine influenza A viruses (S-IAV) was observed
While N1 gene of S-IAVs in this study was closely related to either Eurasian avian-like swine lineage (EA) of endemic Thai-S-IAVs or pdm[09] lineage of pdmH1N1-2009 virus. This result suggested that pdmH1N1-2009 circulated for a period of time or repeat introduced into this pig farm
Summary
We conducted a longitudinal survey of swine influenza A viruses (S-IAV) circulating in a pig farm with history of endemic S-IAV infection from 2017 to 2018. In Thailand, the endemic Thai-S-IAV-H3N2 contained H3 and N2 genes from human-like swine lineage and other internal genes from Eurasian swine lineage (PB1, PB2, PA and M genes) and Classical swine lineage (NP and NS genes)[6]. It has been reported that all major S-IAVs lineages from different continents (CS-H1, EA-H1, pdm2009-like H1, American TR, human-like H3, European H3N2, Avian-like viruses etc.,) are co-circulating in pigs in Asia including Thailand. The objective of this study was to conduct a longitudinal survey of S-IAVs circulating in a pig farm with history of endemic S-IAV infection from 2017 to 2018. Genetic diversity of S-IAVs and evidence of genetic reassortment of S-IAVs in a pig farm was investigated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
