BOSTON (AP) — The Ebola outbreak in West Africa is focusing a spotlight on an online tool run by experts in Boston that flagged a “mystery hemorrhagic fever” in forested areas of southeastern Guinea nine days before the World Health Organization formally announced the epidemic.

HealthMap uses algorithms to scour tens of thousands of social media sites, local news, government websites, infectious-disease physicians’ social networks and other sources to detect and track disease outbreaks. Sophisticated software filters irrelevant data, classifies the relevant information, identifies diseases and maps their locations with the help of experts.