H9N2 AI Virus Diagnosed in China.

12/27/2018

A posting on ProMED Mail documents two sporadic cases of H9N2 avian influenza in infants resident in Guangdong and Guangxi Provinces respectively. The virus is transmitted from infected flocks to humans usually with a history of exposure to live chickens or to poultry in wet markets. Infants, the elderly and the immunosuppressed are most likely to demonstrate clinical signs and frequently require hospitalization.

 

The ProMED moderator posted the following commentary:-

 

H9N2 influenza viruses of the Eurasian lineage have been shown to contribute the six internal gene segments of the highly pathogenic H5N1 influenza virus after the first human case was reported in 1997. Phylogenetically, the Eurasian H9N2 influenza viruses can be classified into three groups represented by prototype viruses, namely A/Quail/Hong Kong/97 (G1 lineage), A/Duck/Hong Kong/Y280 (Y280 lineage), and A/Chicken/Korea 38349--p96323/96 (Korean lineage).

 

The H9N2 viruses of the G1 lineage have spread throughout the poultry industry of Eurasia and are particularly prevalent in chickens, causing low-pathogenic inapparent infections unless the birds are coinfected with other poultry disease agents.

According to the WHO monthly risk assessments until November 2018, 38 human cases of avian influenza A/H9N2 had been reported. One of the two most recent incident cases had a history of direct contact with live poultry.

Due to the constantly evolving nature of influenza viruses, WHO continues to stress the importance of global surveillance to detect virological, epidemiological, and clinical changes associated with circulating influenza viruses that may affect human (or animal) health, especially over the coming winter months. Continued vigilance is needed within affected and neighbouring areas to detect infections in animals and humans. Collaboration between the animal and human health sectors is essential. As the extent of virus circulation in animals is not clear, epidemiological and virological surveillance and the follow-up of suspected human cases should remain high.






















































































































































Top