Department of Infectious Diseases,School of Population Medicine and Public Health,Chinese Academy of Medical Science & Peking Union Medical College,Beijing 100730,China

WorldPop,School of Geography and Environmental Science,University of Southampton,Southampton,S0171BJ,UK

Department of Epidemiology and Health Statistics,School of Public Health,Nanjing Medical University,Nanjing,Jiangsu 211166,China

Department of Occupational Health and Environmental Health,West China School of Public Health,Sichuan University,Chengdu,Sichuan 610041,China