禽流感
Influenza A virus subtype H7N9 (A/H7N9) is a bird flu strain of the species Influenza virus A (avian influenza virus or bird flu virus). Avian influenza A H7 viruses normally circulate amongst avian populations with some variants known to occasionally infect humans. An H7N9 virus was first reported to have infected humans in March 2013, in China. Cases continued to be reported throughout April and then dropped to only a few cases during the summer months. At the closing of the year, 144 cases had been reported of which 46 had died. It is known that influenza tends to strike during the winter months, and the second wave, which began in October, was fanned by a surge in poultry production timed for Chinese New Year feasts that began at the end of January. January 2014 brought a spike in reports of illness with 96 confirmed reports of disease and 19 deaths. As of April 11, 2014, the outbreak's overall total was 419, including 7 in Hong Kong, and the unofficial number of deaths was 127.