Avian influenza: Emerging infectious disease.

The highly pathogenic avian influenza (HPAI)A virus subtype H5,have been circulating among poultry in several countries in Asia and Africa for many years. The HPAI virus have caused hundreds of infections in humans and has poised public health threat.This prompted the government of China to embark on mass vaccination of flock and culling of infected birds. The protocol was effective because the virus was curtailed,thus saving lives and preserving animal production lines, but it had some major disadvantages. The protocol is expensive, and the government is currently seeking ways to stop the mass vaccination.The key disadvantage was that subclinical levels of HPAI was found among vaccinated chicken,where the H5N1 had evolved into multiple H5N2 genotypes which are all vaccine-escape variants.(emerging infections journal vol 20. Num 12-Dec 2014) The vaccination played an important role at the onset,but resulted in production of other variants that are highly pathogenic and pose a more fatal threat .This clearly shows that vaccination of flock is not the way to combat the virus, rather education of the populace,bio security,surveillance,rapid diagnosis and culling/destruction of infected birds.