Ecological epidemiology of Avian influenza H5 in Quang Binh

Abstract

The occurrence and transmission of Avian influenza virus (AIV) are still important issues to the wildlife
animals and human health in many places around the world. The outbreaks and circulations of this virus
were studied in different ecological systems. However, the ecological determinants associated with risk of
highly pathogenic avian influenza (HPAI) which was considered as the differences on the geographical,
environmental, agricultural ecology conditions and the risky factors. This study aimed to characterize the
ecological epidemiology of avian influenza virus H5 in Quang Binh province in 2016 so as to find out the
better intervention solutions in HPAI H5 epidemic prevention. The studied results showed that 2 factors,
such as sunlight hour number and wildlife birds related closely to avian influenza A/H5 sero-prevalence
and avian influenza virus circulation in Quang Binh province. There were 5 avian influenza A (H5N6)
virus strains detected in Quang Bình having similarity level of HA gene sequence up to 89-99% in
comparison with those of H5N6 virus strains isolated in Viet Nam and 96-97% with the isolates in other
countries. Genetic and phylogenetic analyses revealed that these viruses were classified into the genetic
clade 2.3.4.4C and were closely related to HPAI (H5N6) viruses that recently detected in Viet Nam,
China, South Korea and Japan. Combination of the technical solutions including reduction of the risky
factors, vaccination, surveillance in post-vaccination, improvement on the avian influenza knowledge for
the poultry farmers could reduce the transmission of avian influenza virus at the farm levels.