A study of how Twitter responded to the 2014 ebola outbreak in West Africa has revealed that the social network beat the official health ministries by three days when it came to spotting the beginnings of the epidemic.
Michelle Odlum and Sunmoo Yoon from Columbia University Medical Center in the US analysed 42,236 ebola-related tweets that were sent between 24 July and 1 August 2014 - the week leading up to the official announcement of the first probable ebola case.
They found that tweets mentioning ebola started to rise in Nigeria 3-7 days before the announcement - and those tweets reached more than 9 billion people (though no doubt many of the recipients are counted multiple times). Topics discussed included risk factors, prevention education, disease trends and compassion.
"These results indicate how Twitter can be used to support early warning systems in outbreak surveillance efforts in settings where surveillance systems are not optimal," wrote the authors of the study, which was published in the American Journal of Infection Control. "[Social network] data have and will continue to prove valuable in support of global health efforts and outcomes."
While the outbreak has ended in Nigeria, Mali, Senegal and Liberia, it still continues in Sierra Leone and Guinea - where almost 100 people are still dying of the virus each week. If you'd like contribute to the efforts to halt its spread, you can donate to the International Rescue Committee.