Mainland H7N9 avian flu cases yesterday single-day increase in 14 cases, up to the explosive epidemic, has accumulated 77, 14 people were killed. Father and son and the couple has infected Shanghai, for the earlier, the CHP sent a letter to all doctors deadly new viruses or limited human-human transmission.
Mainland experts disclosed that one gene mutation of the H7N9 virus first appeared in the H5 and H7 viruses, caused by a new virus adhesion in human upper respiratory tract cells, compared to is H5N1 more easily through droplets human-to-human transmission.
Representatives of the Hong Kong Society for Infectious Diseases Tsang Tak Yin refers the past H5N1 virus majority can only be so in the human body respiratory tract (lung) the cell protein -2,3 identification of both to adhesion together, but the H7N9 virus due to the Q226L location gene mutation upper respiratory cell protein-2 ,6 identification, cause lets combination of virus propagation in the upper respiratory tract, which is similar to a lot of seasonal influenza virus, so when the person coughs, the virus can be upper respiratory ejected infect another person growth opportunities for human-to-human transmission, but the H5N1 virus, the majority of the lower respiratory tract breeding, it is not easy human-to-human transmission.
