[1] Fudan Univ, Sch Publ Hlth, Shanghai 200032, Peoples R China
[2] London Sch Hyg & Trop Med, Dept Infect Dis Epidemiol, London WC1E 7HT, England
[3] Fudan Univ, NHC Key Lab Hlth Technol Assessment, Shanghai 200032, Peoples R China
[4] Anhui Ctr Dis Control & Prevent, Hefei 230061, Peoples R China
[5] Shaanxi Ctr Dis Control & Prevent, Xian 710054, Peoples R China
[6] Nanshan Ctr Dis Control & Prevent, Shenzhen 518054, Peoples R China
[7] London Sch Hyg & Trop Med, Dept Global Hlth & Dev, London WC1E 7HT, England
[8] Univ Washington, Dept Hlth Metr Sci, Seattle, WA 98195 USA