BEIJING (NYTIMES) - For days, Li Bin had what felt like a cold, with a high fever of between 102 and 105, and he could not understand why he wasn't getting better.

After four days, he went to a hospital, and a doctor told him he had a form of viral pneumonia, without offering specifics. Li, 42, was hospitalised, then transferred to another facility and quarantined with other patients who had similarly unexplained symptoms.