Virology & Mycology
Open Access

Emergence and development of the novel H7N9 and H10N8 influenza viruses in China

International Conference on Flu

June 08-10, 2015 Chicago, USA

Huachen Zhu

Posters-Accepted Abstracts: Virol-mycol

Abstract :

The occurrence of human infections with the novel avian H7N9 and H10N8 influenza virus since 2013 in China demonstrates the continuing threat posed by zoonotic pathogens. The repeated re-emergence in the past winter seasons and the ongoing outbreaks of H7N9 raised concerns of new pandemic threats. However, the emergence/re-emergence and development of these viruses are not fully understood. Through a combination of active surveillance, screening of virus archives and evolutionary analyses, we found that H7 and H10 viruses have frequently transferred from wild birds to domestic ducks and then further transmitted to chickens in China on several independent occasions. Subsequently they reassorted with enzootic H9N2 viruses to generate the H7N9 or H10N8 outbreak lineages. The H7N9 outbreak lineage has spread over a large geographic region and become persistent in chickens at live poultry markets that appear to be the immediate source of human infections. This has led to the establishment of multiple regionally distinct lineages with different reassortant genotypes. Most of the H7N9 and H10N8 variants were readily infectious in ferrets and some even had the airborne transmissibility. Continued prevalence of this family of viruses in poultry could lead to further sporadic human infections with an ongoing risk that the virus might acquire efficient human-to-human transmissibility.