In Bangladesh, highly pathogenic avian influenza (HPAI) virus subtype H5N1 was first detected in February 2007. Since then the virus has become entrenched in poultry farms of Bangladesh. There have so far been seven human cases of H5N1 HPAI infection in Bangladesh with one death. The
objective of the present study was to investigate the molecular evolution of H5N1 HPAI viruses during 2007 to 2012. Partial or complete nucleotide sequences of all eight gene segments of two chicken isolates, five gene segments of a duck isolate and the haemagglutinin gene segment of 18 isolates
from Bangladesh were established in the present study and subjected to molecular analysis. In addition, full-length sequences of different gene segments of other Bangladeshi H5N1 isolates available in GenBank were included in the analysis. The analysis revealed that the first introduction
of clade 2.2 virus in Bangladesh in 2007 was followed by the introduction of clade 220.127.116.11 and 2.3.4 viruses in 2011. However, only clade 18.104.22.168 viruses could be isolated in 2012, indicating progressive replacement of clade 2.2 and 2.3.4 viruses. There has been an event of segment re-assortment
between H5N1 and H9N2 viruses in Bangladesh, where H5N1 virus acquired the PB1 gene from a H9N2 virus. Point mutations have accumulated in Bangladeshi isolates over the last 5 years with potential modification of receptor binding site and antigenic sites. Extensive and continuous molecular
epidemiological studies are necessary to monitor the evolution of circulating avian influenza viruses in Bangladesh.
No Reference information available - sign in for access.
No Citation information available - sign in for access.
No Supplementary Data.
No Article Media
Document Type: Research Article
Department of Pathology, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh
National Reference Laboratory for Avian Influenza, Bangladesh Livestock Research Institute, Savar, Bangladesh
March 4, 2014
More about this publication?