Objective  To compare the evolution process of network public opinion about avian influenza A H7N9 virus (H7N9) epidemic in 2013 and 2017 in China for making constructive suggestions to guide and control network public opinion about the issue under social media environment.

  Methods  We collected and analyzed information on network public opinions towards H7N9 epidemic during the epidemic periods from March to May 2013 and from February to April 2017 via Baidu Index and Sina Micro-Public Opinion Big Data Platform. Then we compared dynamic changes in the communication of the opinions between the two periods using descriptive and graphical method.

  Results  The diagrams for variation in network public opinions towards H7N9 epidemic during the two periods showed a four-stage (prodromal, outburst, fluctuation, and regression stage) pattern. Compared to that in 2013, the fluctuation in the network public opinions was relatively low, suggesting a decreased concern on the H7N9 epidemic among the public. The imbalance in risk cognition among the public led to increased communication of opinions on H7N9 epidemic and rumor spreading. The use of new media, especially the use of microblog, obviously enhanced the influence of social media on public opinions about H7N9 epidemic.

  Conclusion  Governmental agencies should strengthen the guidance and supervision on network public opinions on communicable disease epidemic under social media environment and efforts need to be taken by social media, the public, and governmental agencies for the establishment of an active media environment beneficial for the control of communicable disease epidemic.