The coronavirus had infected 74,651 people in China as of 20 February, with 2,120 of them dying. It seems to start with a fever, followed by a dry cough. After a week, it leads to shortness of breath and some patients require hospital treatment. Notably, the infection rarely seems to cause a runny nose or sneezing. The incubation period – between infection and showing any symptoms – lasts up to 14 days, according to the World Health Organization (WHO). But some researchers say it may be as long as 24 days. And Chinese scientists say some people may be infectious even before their symptoms appear.