Sự lưu hành và biến đổi di truyền của virus cúm gia cầm Type A H5N1 trên gia cầm tại một số tỉnh Đồng bằng sông Cửu Long

Abstract

Avian influenza disease is an acute infectious disease of avian caused by Orthomyxoviridae virus. The present study on the circulation and genetic variation of type A H5N1 avian influenza virus in Hau Giang, Soc Trang, Tra Vinh and Vinh Long provinces has been conducted by sampling swabs on poultry (healthy chicken and duck) trading at live bird market or slaughterhouses. The swab samples were tested using Real time RT-PCR technique to identify type A H5N1 avian influenza virus and to define the rate of prevalence and further implement HA gene sequencing for determination of genetic variation and clade. It was shown that the average prevalence of type A H5N1 avian influenza virus on poultry in above provinces in the Mekong delta was 6,5% whereas the prevalence of type A H5N1 avian influenza virus on duck and chicken was 9,7% and 4%, respectively. Besides, results of genetic variation investigation showed that nucleotide differentiation between circulating strains in the provinces and the reference strain A/Hong Kong/6841/2010 was from 2.3 – 3.2% . The amino acid sequence motif at connecting position between HA1 and HA2 segment was Q-ERRRKR-G and similar to the sequence of reference strain A/Hong Kong/6841/2010. The strains of type A H5N1 avian influenza virus circulating in the provinces of Hau Giang, Soc Trang, Tra Vinh and Vinh Long belong to virus clade of 2.3.2.1c.