Interferences Between Avian Influenza, Poultry and Human Health

From time to time, experts from renowned organizations give dire warning about the threat of H5N1 highly pathogen avian influenza (HPAI) to the human population. It is the H5N1 strain which is infecting humans and causing high death rates. In effect, H5N1 HPAI is now endemic to Asia: it hides virtually undetected in domestic ducks and crosses national borders in migrating wildfowl. Given the high incidence of H5N1 HPAI in poultry flocks across Asia and the close human contact, the number of people infected has been remarkably low. The current virus has difficulty transferring from poultry to humans. In the most cases where this has occurred, transfer has been traced to the most intimate and unnecessary human contact with poultry, and therefore exposure to high concentrations of virus particles. There is a little evidence for the direct transfer of H5N1 HPAI between humans; although the WHO admits that this is the most likely explanation in some cases. Simultaneous infection of humans by avian influenza viruses in the presence of human influenza viruses could theoretically generate novel influenza viruses with pandemic potential as a result of re-assortment of genome subunits between avian and mammalian influenza viruses. These hybrid viruses would have the potential to express surface antigens from avian viruses to which the human population has no preexisting immunity. Avian influenza virus could change so that, it could infect human and could spread easily from person to person. Because, these viruses do not commonly infect humans, there is little or no immune protection against them in the human population. If an avian virus were able to infect people and gain the ability to spread easily from person to person, and influenza pandemic could begin.  

 Key words: Poultry, Human health, Avian influenza, Interference.