Evolution of H9N2 influenza viruses from domestic poultry in Mainland China

摘要: H9N2 viruses have circulated in domestic poultry Mainland China since 1994, and an inactivated vaccine has been used chickens to control the disease 1998. The present study analyzed 27 avian influenza that were isolated from ducks 1996 2002. Infection studies indicated most of replicate efficiently but none them is lethal for SPF chickens. However, these exhibit different phenotypes replication a mouse model. Five viruses, including 4 early isolates one 2000 isolate, are not able mice; 14 moderate titers lungs cause less than 5% weight loss, while other 8 could high 7 induce 10-20% loss mice on day 5 after inoculation. Most antigenically strain currently China. Three central 1998 resistant adamantanes. Phylogenetic analysis revealed all originated CK/BJ/1/94-like virus formed multiple genotypes through complicated reassortment with QA/HK/G1/97-, CK/HK/G9/97-, CK/SH/F/98-, TY/WI/66-like viruses. This description previously uncharacterized recently circulating Our findings suggest urgent attention should be paid animals human's pandemic preparedness.