After Haiti’s earthquake two years ago, cholera swept the country. And within a month, the same strain had spread to the Dominican Republic and the U.S., and then to Venezuela, Mexico, Spain, and Canada.

Fast and accurate tools are needed to help avoid such national and international epidemics. But it often takes weeks for traditional disease surveillance methods to reveal an illness’s spread. So researchers turned to the internet as a possible tracking tool. They culled information in eight languages from sources such as news articles and blogs during the first hundred days after the earthquake. They also searched Twitter.

With data from more than 4,500 reports and nearly 189,000 tweets, they mapped the outbreak and determined its progress, via an application called HealthMap. The information matched official results in certain places and generally followed the same trends. But unlike the officially issued information, this data could be collected immediately—and could have been available up to two weeks faster. The comparison was published in the American Journal of Tropical Medicine and Hygiene. [Rumi Chunara, Jason R. Andrews and John S. Brownstein, "Social and news media enable estimation of epidemiological patterns early in the 2010 Haitian cholera outbreak"]

The scientists say these methods could provide a faster response to an epidemic—and potentially help limit suffering such as Haiti’s in the future.

—Cynthia Graber

[The above text is a transcript of this podcast.]