By the fall of 2014, almost 15,000 cases of dengue fever broke out across Guangzhou, one of China’s largest cities. The metropolis went on to become one of the hardest-hit places by 2014’s global dengue fever outbreak.
During that time, social media was packed with discussions, comments, and posts about the epidemic spread by a mosquito-borne virus. A digital footprint captured people’s hopes, fears, and attempts to understand the outbreak.
Now, researchers from China and the United States have followed these footprints to conduct a pioneering study. In a new paper published in Geomatica, Junfang Gong and colleagues analyzed social media activity during Guangzhou’s dengue fever outbreak to understand when, where, and how social media posts originated and spread.
By understanding how social media data originate during disease outbreaks and combining it with public health statistics, health officials can design and implement intervention programs to minimize the physical, social, and economic toll of such events.
Previous public health research used the occurrence of social media posts to predict and monitor the spread of diseases, but few studies have focused on how social media discussions change and spread over time as diseases progress or abate. So far, we have had snapshots of how discussion of the disease disseminates online, but this new research provides us with moving pictures.
Researchers used the popular social media microblogging site Sina to track discussions of dengue fever.
For the study, the authors collected social media posts on dengue fever outbreak from China’s most popular micro-blogging website, Sina—think a combination of Twitter and Facebook.
Gong and colleagues used a machine-learning algorithm called text mining to discover and extract various topics in social media posts. They statistically analyzed how posts on particular topics like “Southeast Asia” or news events such as “reports of dengue fever in 2014, China” or “prevention of dengue fever” were being noticed, followed, and discussed via comments, reports, and endorsements over time.
According to their research, it took more than 20 days for discussions related to dengue fever to become a hot topic on micro-blogs. The initial period lasted approximately 30 days. After that time, many more micro-blogs on the topic were posted. Users continued the discussion on dengue fever until gradually losing interest in the discussion in a phase that lasted 20 days.
The authors summarized that “given that the spread of dengue fever typically started in late spring and leveled off in late summer or early autumn, the 80-day time period explained the diffusion process very
The authors also used location information of social media posts to figure out if posts with similar topics were originating from similar geographical locations.
By tracking the place and time of origin of the social media posts, the authors were also able to explain the spread of dengue fever in various locations both inside and outside the city. For the latter, they hypothesized that modern transportation networks would move carriers of the virus from one place to another, even over lengthy distances.
Understanding the process of where, when, and how social media posts spread will be critical for leveraging social media to spread public-health related information more accurately and efficiently.
Read the full study: Space, time, and disease on social media: a case study of dengue fever in China in Geomatica.