The 2015 outbreak of Middle East respiratory syndrome (MERS) in the Republic of Korea is the largest outbreak outside the Middle East since MERS was discovered in 2012. Its origin was a single imported case after the patient travelled to endemic countries.

Background：Global Handwashing Day (GHD) is a handwashing promotion campaign organized by the Global Public-Private Partnership of Handwashing with Soap. In China, it has been promoted by the Chinese public health authorities, international organizations and multinational corporations through various channels including social media such as Sina Weibo, the leading Chinese microblogging site similar to Twitter. The objective of this study is to qualitatively assess Chinese social media users’ reactions to a health promotion campaign using Global Handwashing Day (GHD) 2012 as an example.Methods：We conducted a qualitative content analysis of 552 Weibo posts generated on GHD 2012 by Weibo users with 1000 or more followers with the Chinese keyword for “handwashing.” We categorized the Weibo posts into groups by keywords that frequently appeared in the data set. These groups were either exact reposts of an original post, or they conveyed similar information.Results：We observed the interconnections between traditional media and social media in handwashing promotion. Social media were found to serve as amplifiers of contents provided by traditional media. We observed the contextualization of global hygiene messages in a unique national social media market in China.Discussion：Our study showed that social media and traditional media are two interconnected arms of the GHD campaign in China. Our analysis demonstrated that public health campaigns in China can be evaluated using social media data. The themes and topics identified in this study will help public health practitioners evaluate future social media handwashing promotion campaigns.