Affiliation: | 1. Anhui Provincial Family Planning Institute of Science and Technology, Hefei 230031, Anhui Province, China.; 2. Huzhou Center for Disease Control and Prevention, Huzhou 313000, Zhejiang Province, China.; 3. Health management teaching and research section, the first affiliated hospital of Bengbu medical college, Bengbu, Anhui 233000, P.R. China.; Institute of Infection and Global Health, UNITED KINGDOM, |