Appearance of reassortant European avian‐origin H1 influenza A viruses of swine in Vietnam. Issue 4 (6th March 2018)

• Record Type: Journal Article
• Authors: Takemae, N.; Nguyen, P. T.; Le, V. T.; Nguyen, T. N.; To, T. L.; Nguyen, T. D.; Pham, V. P.; Vo, H. V.; Le, Q. V. T.; Do, H. T.; Nguyen, D. T.; Uchida, Y.; Saito, T.
• Is Part Of: Transboundary and emerging diseases. Volume 65:Issue 4(2018)
• Page Start: 1110
• Page End: 1116
• Publication Date: 2018-03-06
• Subjects: European influenza A virus of swine -- influenza A virus -- pig -- Vietnam; Veterinary medicine -- Periodicals; 636.089
• DOI: 10.1111/tbed.12849
• Languages: English
• ISSNs: 1865-1674

Abstract

Summary: Three subtypes—H1N1, H1N2 and H3N2—of influenza A viruses of swine (IAVs‐S) are currently endemic in swine worldwide, but there is considerable genotypic diversity among each subtype and limited geographical distribution. Through IAVs‐S monitoring in Vietnam, two H1N2 influenza A viruses were isolated from healthy pigs in Ba Ria‐Vung Tau Province, Southern Vietnam, on 2 December 2016. BLAST and phylogenetic analyses revealed that their HA and NA genes were derived from those of European avian‐like H1N2 IAVs‐S that contained avian‐origin H1 and human‐like N2 genes, and were particularly closely related to those of IAVs‐S circulating in the Netherlands, Germany or Denmark. In addition, the internal genes of these Vietnamese isolates were derived from human A(H1N1)pdm09 viruses, suggesting that the Vietnamese H1N2 IAVs‐S are reassortants between European H1N2 IAVs‐S and human A(H1N1)pdm09v. The appearance of European avian‐like H1N2 IAVs‐S in Vietnam marks their first transmission outside Europe. Our results and statistical analyses of the number of live pigs imported into Vietnam suggest that the European avian‐like H1N2 IAVs‐S may have been introduced into Vietnam with their hosts through international trade. These findings highlight the importance of quarantining imported pigs to impede the introduction of new IAVs‐S.