Wired just wrote an article on the work I helped with when I was a data scientist at BlueDot. We built a system that ingests news articles from around the world and uses the information to create a database of global infectious disease outbreaks. The product identified the recent coronavirus outbreak a week before the CDC and 10 days before the World Health Organization.
If you want a more technical description of the product, check out this article I wrote with Andrea Thomas-Bachli, Jack Forsyth, Zaki Patel, and Kamran Khan. This was a few years ago now, so I’m not sure if this is still how the system works. Sorry about the paywall - just email me if you can’t access it online.