H9N2 influenza virus in China: a cause of concern.

The recent human infection with avian influenza virus revealed that H9N2 influenza virus is the gene donor for H7N9 and H10N8 viruses infecting humans. The crucial role of H9N2 viruses at the animal-human interface might be due to the wide host range, adaptation in both poultry and mammalian, and extensive gene reassortment. As the most prevalent subtype of influenza viruses in chickens in China, H9N2 also causes a great economic loss for the poultry industry, even under the long-term vaccination programs. The history, epidemiology, biological characteristics, and molecular determinants of H9N2 influenza virus are reviewed in this paper. The contribution of H9N2 genes, especially RNP genes, to the infection of humans needs to be investigated in the future.

近期人类感染禽流感病毒的情况显示，H9N2流感病毒是感染人类的H7N9和H10N8病毒的基因供体。H9N2病毒在动物 - 人界面的关键作用可能是由于其宿主范围广泛，在家禽和哺乳动物中均能适应，以及广泛的基因重配。作为中国鸡群中最流行的流感病毒亚型，即使在长期的疫苗接种计划下，H9N2也给家禽业造成了巨大的经济损失。本文综述了H9N2流感病毒的历史、流行病学、生物学特性和分子决定因素。未来需要研究H9N2基因，尤其是核糖核蛋白（RNP）基因对人类感染的作用。