When online content is shared widely and rapidly, it is considered to be “viral media” – spreading much like an infection. The Ice Bucket Challenge to raise awareness and support for amyotrophic lateral sclerosis (ALS) is considered to be a viral media phenomenon, with more than 17 million related videos having been viewed more than 10 billion times by over 440 million people. How transmissible was the Ice Bucket Challenge among globally influential celebrities compared to specific infectious disease outbreaks?

In a new BMJ study, researchers reviewed celebrities with global influence (defined by the criteria: having been listed in the TIME 100: The Most Influential People in the World or TIME: Great People of the 20th Century, or having at least five million views for their Ice Bucket Challenge video on YouTube. From there, celebrities David Beckham, Cristiano Ronaldo, Benedict Cumberbatch, Stephen Hawking, Mark Zuckerberg, Oprah Winfrey, Homer Simpson, and Kermit the Frog were arbitrarily selected as index cases. Among those who had received a challenge, 9.1% completed the challenge but did not nominate others to complete the challenge as well (what the authors call “self-isolation”). This is remarkably similar to the 2009 H1N1 influenza pandemic, which had a mean serial interval of 2.8 days and a basic reproduction number (R0) of 1.2–2.3 vs. the Ice Bucket Challenge’s 2.1 days and 1.4 R0.

Factors contributing to the viral spread of the Ice Bucket Challenge include the online social media mode of transmission and the short serial interval for completing the challenge; factors contributing to the spread of H1N1 include person-to-person contact and lack of vaccination against the influenza virus.

READ FULL ARTICLE Curated publisher From Bmj