As the number of coronavirus cases rises, epidemiologists around the world look at maps, flight bookings and population data to estimate the size of the outbreak—and explain why their results are higher than China’s official tally. Photo: Getty Images
More from the Wall Street Journal:
Visit WSJ.com: http://www.wsj.com
Visit the WSJ Video Center: https://wsj.com/video
On Facebook: https://www.facebook.com/pg/wsj/videos/
On Twitter: https://twitter.com/WSJ
On Snapchat: https://on.wsj.com/2ratjSM
▶️ DTube
▶️ YouTube