New York: Tweets regarding the Ebola outbreak in West Africa last year reached more than 60 million people in the three days before the official outbreak announcements, a new study has found.

Researchers from the Columbia University School of Nursing in New York analysed over 42,000 Ebola-related tweets posted to the social networking site Twitter, from July 24 to August 1, 2014, the week in which Nigeria reported the first case of Ebola, Sierra Leone declared a national state of emergency and the first American was diagnosed with Ebola.

Twitter was a resource for those to share news of Ebola cases prior to official announcements from the Nigerian Ministry of Health, the World Health Organisation and the Centers for Disease Control and Prevention.

During the three days prior to an official announcement from the Nigerian Ministry of Health nearly 1,500 tweets were disseminated regarding Ebola.

"Twitter adoption in African countries like Nigeria has been exponentially increasing and it's clear that Twitter is a useful resource for spreading breaking health news in these West African countries," said the study authors in the American Journal of Infection Control.

"The results of this analysis indicate how Twitter can be used to support early warning systems in outbreak surveillance efforts in settings where surveillance systems are not optimal," they said.

Content analysis of the tweets showed that the main topics of concern in the tweets were Ebola risk factors, prevention education and health information, spread and location of Ebola, and compassion for countries in Africa.