Epidemiological characteristics and control strategies of avian influenza A (H7N9) / 第二军医大学学报

ABSTRACT

A novel avian influenza was discovered in Mainland China in March 2013, and the virus was identified as avian influenza A (H7N9)-anew virus that has not been reported previously before. Further research showed that the virus was probably a combination of three different subtypes of influenza A virus. By May 31, a total of 131 confirmed cases have been reported in China, including 39 deaths. Shanghai reported 33 confirmed cases, with the onset of 29 cases found before closing the live poultry markets by the municipal government on April 6. The onsets of the rest 4 cases were all found during the first incubation period after the closure. We found that 66. 7% (22/33) of the confirmed cases in Shanghai were above 60 years of age, and of the 15 deaths, 80% (12/15) were aged above 60 years old. It was also noted that 90. 9% (30/33) of the confirmed cases had an exposure history to susceptible animals orenvironmental circumstances. The cases appeared to be sporadic; although there were two family clusters, no evidence of human-to-human transmission has been found so far. Shanghai municipal government activated the Flu Pandemic Preparedness and Response Plan (Level IH ) onApril 2, 2013, timely after the first few cases was identified. The rapid responses of public health emergencies included citywide suspending of live poultry markets, health education, and risk communication; the epidemic was controlled effectively and timely. In this paper we analyzed the pros and cons of our prevention and control strategies, hoping to provide reference for future epidemics.