Avian influenza viruses continue to present challenges to human health. Recently the H7N9 and H10N8 viruses that are of low pathogenicity for poultry have caused human infections and deaths in China. H9N2 influenza virus have been isolated worldwide from wild and domestic avian species for several decades, and their low pathogenic nature to poultry made them a low priority for animal disease control, which has allowed them to continue to evolve and spread.

The animal influenza team of HVRI, CAAS, investigated a series of H9N2 influenza viruses that were detected in live poultry markets in southern China. They found that these viruses are able to preferentially bind to the human-type receptor, and some of them can cause disease and transmit between ferrets by respiratory droplet. All the transmissible H9N2 viruses have a similar internal gene constellation, which was also present in the H7N9 and H10N8 viruses. Their study indicates that the widespread dissemination of H9N2 viruses poses a threat to human health not only because of the potential of these viruses to cause an influenza pandemic, but also because they can function as “vehicles” to deliver different subtypes of influenza viruses from avian species to humans. Their research results were published recently in the Journal of PLoS Pathog.

For more information:
http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004508