Massive study on Ebola-related Tweets debunks the importance of “going viral” on Twitter, among other surprises

As Twitter has grown to be a communication point for far reaches of the globe, there is increasing concern that a failed Twitter communication strategy can have life-threatening consequences, especially when Twitter is used to disseminate information about an emerging infectious disease outbreak.

Here is the problem:  “Going viral” is an elusive and rare achievement and yet it is widely presented as the go-to model for effectively spreading information on Twitter. The result in the public health world is a cruel puzzle that no one can seem to solve: How do we spread potentially life-saving information on a global medium with a model that is somehow both crucial and yet also elusive to master?

Enter: A new kind of question.

What if the viral model isn’t crucial for spreading information on Twitter?

This was an underlying question for a recent study funded by the CDC, which analyzed over 36 million Ebola-related tweets posted globally from March 2014 to May 2015. The results of that study, published in BMC Public Health, reveal some surprising details about what model and what types of Twitter users were the most effective in spreading Ebola information. Here are the highlights:

The broadcast model—not the viral model—dominated information movement on Twitter.

91% of the retweets about Ebola were directly retweeted from an initial message. 47.5% of those retweets had a depth of 1. It was broadcast info through and through. As the study concluded,

“Viral information cascades on Twitter are rare events that public health agencies would not build communication strategies around.”

But there’s a bit of a surprise coming up…

Media and health organization accounts were responsible for only 12.8% of all retweets in the dataset.

Big organization accounts like BBC, CDC, and WHO are known for using the broadcast model. The CDC Emergency Twitter account alone has 1.8 million followers, which would make many assume that this and other organization accounts like it were the most influential Tweeters in the dataset. But it appears that this is not at all the case. Instead…

Personal accounts of celebrities or the accounts of sports organizations are responsible for most of the retweets about Ebola.

Cited accounts include Barack Obama (107.6mill followers), Bill Gates (47.7mill), and FC Barcelona (30.4mill). The study suggests that public health communicators should utilize “influential users” like these in strategies because they “can reach more people that are not following the public health Twitter accounts.” That being said, no celebrity/sports account can claim the most retweeted tweet in relation to Ebola.

The most retweeted tweet was posted by a user with only 2421 followers.

In addition to that, 2 of the top 10 retweeted tweets were posted by accounts with less than 1000 followers. In its discussion, the study asked the question many would wonder as well:

“Did they simply by chance write an Ebola-related tweet that became viral? Or are they individuals who are masters of online communication and can write tweets in a way that health organizations cannot?”

As it turns out, many of these “hidden influential users” were categorized as “humorous accounts,” a discovery which echoes other studies on Ebola-tweets in 2014. Thus the idea of utilizing them as part of a (cost-effective) communications strategy should be tempered by the very strong possibility that the tweets on Ebola which did go viral, were jokes about Ebola rather than masterfully-crafted public health information.

The takeaways:

This research is especially helpful for those of you who tweet from personal accounts about public health and specifically about Sustainable Development Goal 3: Good Health and Well-Being. Here are two immediate takeaways:

  • Know your most influential followers by checking out your Twitter analytics report each month. The study’s findings suggest that more people will receive your public health info if these particular followers retweet you.
  • Expand your followers/followees to accounts outside public health. The results of the study are clear: non-media and non-health organizations played a huge part in the dissemination of Ebola-related tweets. Get creative and reach out.


Hai Liang, Isaac Chun-Hai Fung, Zion Tsz Ho Tse, Jingjing Yin, Chung-Hong Chan, Laura E. Pechta, Belinda J. Smith, Rossmary D. Marquez-Lameda, Martin I. Meltzer, Keri M. Lubell & King-Wa Fu  (2019). “How did Ebola information spread on twitter: broadcasting or viral spreading?” BMC Public Health 19. 438.

The Social Diplomat is a blog-post series showing how recent research on various topics in media and development can help you, our social media users at the UN, achieve the common goal of connecting the public to your work.

Tarah Van De Wiele

Dr. Tarah Van De Wiele is a freelance writer living in Pennsylvania. She specializes in the sustainability market and movement. When she isn't writing, she's reading any book that is too long and needs a map of its fantasy world. She's also well-trained by her dogs.

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