HealthMap tracks Ebola’s footprints online, preparing for the next big outbreak


Since March, a group of data-savvy epidemiologists at Boston Children’s Hospital have watched Ebola slowly spread through West Africa, ominously lighting up their dials first as a trickle, then a torrent of mentions on social media and online news reports.

The group, HealthMap, has been steadily ahead of the curve tracking this year’s outbreak. One day, they hope to be a step ahead of the next big disease.

HealthMap’s goal is to get reliable, real-time information to the public, to governments and to public health organizations, about the infectious disease outbreaks that may be near them. In a time when patients are Googling their symptoms before calling in to book an appointment with their doctors, it is a particularly timely mission.

“Our goal is unique in that we strive to create visuals and tools that are available to the general public,” said HealthMap co-founder John Brownstein, an epidemiologist with appointments at Harvard Medical School and Boston Children’s Hospital.

HealthMap mines public data in 15 languages, including tweets, news reports, and public information from government and public health groups, searching for mentions of disease names or symptoms. The data is geocoded when possible, then presented on HealthMap’s map-based visual display, after weeding out noise and false alerts.

HealthMap has been around for eight years, and in that time tracked SARS, H1N1, MERS, the flu, and more. But this year’s Ebola outbreak — the first in West Africa and the most widespread incidence of this disease to date, for biological reasons and other reasons — has been different in many ways.

“Often times most events that we track are clustered and they died out,” Brownstein said. Not Ebola. “This is a growing catastrophe. We’re seeing it unfold almost in slow motion and it’s unique.”

In the last few months, HealthMap has been matching the public’s thirst for information as the disease took over one country, then another.

For the first time, the group has presented a historical account of Ebola’s spread, from the very first mentions of the case in online news reports in mid-March this year. Also a first, the group has modeled the spread of the disease, and offers projections for how many it could fell, in each of the three countries infected so far.

In the last two months, has collected more than a million page views, Brownstein says. That’s not all: People are emailing the group every day with questions.

Brownstein is quick say that his group does not hope to replace federal disease trackers like the CDC. Rather, he hopes his researchers can provide an easy-to-digest and accurate reference for government organizations as well as the curious public.

For example, breaking with tradition, Maia Majumder, a PhD student at MIT and a member of HealthMap, presented an alternate way of tracking Ebola’s reach, suggesting that the actual body count may be easily double numbers that organizations like the World Health Organization were reporting. (That post has been viewed more than 24,800 times, according to HealthMap’s count.)

Besides Ebola, HealthMap has a number of other projects underway, each pushing the envelope for the kinds of data that can be extracted from social channels. Rumi Chunara, an instructor at Harvard Medical School, has been tracking and predicting the spread of the common flu virus. From Yelp reviews, post-doctoral researcher Elaine Nsoesie is building a reliable way to identify outbreaks of food poisoning and zoom in on the kinds of foods that caused them.

With the Ebola outbreak unfinished, HealthMap has ongoing collaborations around the world. HealthMap members are working with Kamran Khan at St. Michael’s Hospital in Toronto to match transportation data and flight information with the paths taken by the outbreak. Through another partnership with Simon Hay‘s lab at the Oxford University, the groups hopes to focus on geography, and determine which locations are currently ripe for Ebola to spread.

The deep-dive tools that HealthMap has built to track Ebola can be used to track other outbreaks, Brownstein said. The goal, for when the next one breaks, is for HealthMap to help all of us be just a little better prepared.

Nidhi Subbaraman writes about science and research. Email her at [email protected]
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