Nearly two decades ago, China was at the heart of a public health crisis over a deadly new virus. It said it had made lifesaving reforms since. So why is the Wuhan coronavirus now spreading so rapidly across the world? Our correspondent went to the center of the outbreak to find out. Guest: Javier C. Hernández, a New York Times correspondent based in Beijing. For more information on today’s episode, visit nytimes.com/thedaily. Background reading: What is the coronavirus? And why is China struggling to control its spread around the world?Unless you are at high risk for catching the disease, it may be a good idea to avoid buying a face mask. There is now a shortage of masks, leaving health care workers unprotected and expediting the spread of the disease.