Avian H9N2 influenza A virus has caused repeated human infections in Asia since 1998. Here we report that an H9N2 influenza virus infected a 5-year-old child in Hong Kong in 2003. To identify the possible source of the infection, the human isolate and other H9N2 influenza viruses isolated from Hong Kong poultry markets from January to October 2003 were genetically and antigenically characterize...

Avian influenza A H9N2 viruses are widespread among domestic poultry and were recently isolated from humans with respiratory illness in China. Two antigenically and genetically distinct groups of H9N2 viruses (G1 and G9) are prevalent in China. To evaluate a strategy for vaccination, we compared G1 and G9 viruses for their relative immunogenicity and cross-protective efficacy. Infection of BALB...

Routine surveillance of influenza A virus was conducted in Myanmar during 2014-2015. Influenza A(H9N2) virus was isolated in Shan State, upper Myanmar. Whole-genome sequencing showed that H9N2 virus from Myanmar was closely related to H9N2 virus of clade 4.2.5 from China.

BACKGROUND   The highly pathogenic H5N1 and H9N2 influenza viruses are endemic in many countries around the world and have caused considerable economic loss to the poultry industry. Objectives  We aimed to study whether a live attenuated H5N1 vaccine comprising internal genes from a cold-adapted H9N2 influenza virus could protect chickens from infection by both H5N1 and H9N2 viruses. METHODS ...

We characterized low pathogenic avian influenza (LPAI) H5N2 and H9N2 viruses isolated in South Korea from 2008 to 2009. Genetic analysis of the H5N2 viruses isolated from wild birds and domestic ducks demonstrated that they were related to the recently isolated southern Chinese LPAI H5 viruses and various influenza viruses circulating in Eurasia. Three H9N2 viruses obtained at live bird markets...

Avian influenza H9N2 viruses have become panzootic in Eurasia causing respiratory manifestations, great economic losses and occasionally being transmitted to humans. To evaluate the replication properties and compare the different virus quantification methods, four Eurasian H9N2 viruses from different geographical origins were propagated in embryonated chicken egg (ECE) and Madin-Darby canine k...

H9N2 influenza A viruses are currently widespread in chickens, quail, and other poultry in Asia and have caused a few cases of influenza in humans. In this study, we found that H9N2 viruses from Hong Kong live bird markets have receptor specificity similar to that of human H3N2 viruses. In addition, the neuraminidase of poultry H9N2 viruses has mutations in its hemadsorbing site, a characterist...

Since 1994, the H9N2 avian influenza virus (AIV) has spread widely in mainland China, causing great economic losses to the poultry industry there. Subsequently, it was found that the H9N2 AIV had the ability to infect mammals, which gave rise to great panic. In order to investigate the immune response of a host infected with H9N2 AIV, TC-1 cells were set as a model in this research. Quantitativ...

BACKGROUND H9N2 avian influenza viruses that circulate in domestic poultry in eastern China pose challenges to human health. However, few studies have compared the biological characteristics of H9N2 viruses isolated from healthy chickens in Shanghai. MATERIAL AND METHODS Three H9N2 viruses - CK/SH/Y1/07, CK/SH/Y1/02, and CK/SH/23/13 - isolated from healthy chickens in Shanghai between 2002 and ...