What You Need to Know About the Coronavirus Pandemic
Health official disinfect a market in Sofia on March 12.
Photographer: Nikolay Doychinov/AFP via Getty Images
The newly identified coronavirus that emerged late last year in central China started a pandemic that’s already killed tens of thousands of people. Most deaths have been in Europe, and the U.S. now has the most confirmed cases of any country. While it took three months for the first 100,000 cases globally, the next 100,000 appeared in 12 days, and the total doubled again in barely a week. The contagiousness of the virus, which causes a lung illness dubbed Covid-19, has health experts worried it could rival the most devastating outbreaks in recent decades.
(This story updates with new data on contagiousness in section 8 and new information about the possibility of re-infection in section 9.)