The coronavirus appears to be much more lethal in some countries than in others.
In Italy, about 10% of people known to be infected have died. In Iran and Spain, the case fatality rate is higher than 7%. But in South Korea and the U.S. it's less than 1.5%. And in Germany, the figure is close to 0.5%.
So what gives?
The answer involves how many people are tested, the age of an infected population and factors such as whether the health care system is overwhelmed, scientists say.