[1] Chinese Ctr Dis Control & Prevent, Natl Ctr AIDS STD Control & Prevent, State Key Lab Infect Dis Control & Prevent, Epidemiol & Biostat Branch,Div Virol & Immunol, Beijing 102206, Peoples R China
[2] Chinese Ctr Dis Control & Prevent, State Key Lab Infect Dis Prevent & Control, Beijing 100050, Peoples R China
[3] Chinese Ctr Dis Control & Prevent, Natl Ctr AIDS STD Control & Prevent NCAIDS, Beijing 100050, Peoples R China
[4] Chaoyang Ctr Dis Control & Prevent, Beijing 100021, Peoples R China
[5] Vanderbilt Univ, Inst Global Hlth, Nashville, TN 37023 USA
[6] Vanderbilt Univ, Dept Prevent Med, Nashville, TN 37023 USA
[7] Chaoyang Chinese AIDS Volunteer Grp, Beijing 100021, Peoples R China