Li Lanjuan, a renowned Chinese epidemiologist, waves to people before leaving Wuhan, central China's Hubei Province, March 31, 2020. Medical staff leading by Li Lanjuan left Wuhan after finishing their task here on Tuesday. Li is an academician with the Chinese Academy of Engineering, who heads the State Key Laboratory for Diagnosis and Treatment of Infectious Diseases. (Xinhua/Fei Maohua)
