The global spread of infection from the new virus reached a critical stage this week with the number of new cases reported in the rest of the world surpassing the number of new cases in China, where the emergency began.
Reflecting how tourism and business travel unite the planet, Antarctica is the only continent with no reported cases of the illness COVID-19. Troubling outbreaks in South Korea, Japan, Italy and Iran have seeded cases elsewhere as travelers bring the virus home with them.
With the world at a tipping point, there was hopeful new evidence from China showing that containment is possible. And as more mild cases are counted, experts said, the death rate may be more like seasonal flu than like previous new coronavirus outbreaks.
Here's what you should know about the illness:
WHAT DO WE KNOW ABOUT THE DEATH RATE?
The death rate from COVID-19 was 1.4% in the latest report from Chinese health officials on 1,099 patients with confirmed disease at more than 500 hospitals throughout China.
The report, published Friday by the New England Journal of Medicine, gives a much broader view of the outbreak beyond Wuhan, where it started and has been most severe.
Assuming there are many more cases with no or very mild symptoms, "the case fatality rate may be considerably less than 1%," U.S. health officials wrote in an editorial in the journal.