[Zhao, Xiuqin; Lian, Lulu; Zhang, Jingrui; Li, Guilian; Wan, Kanglin; Dong, Haiyan] Chinese Ctr Dis Control & Prevent, Natl Inst Communicable Dis Control & Prevent, Beijing 102206, Peoples R China.
[Wu, Yimou; Lian, Lulu; Wan, Kanglin] Univ South China, Pathogen Biol Inst, Hengyang, Hunan, Peoples R China.
[Deng, Jianping; Xiao, Tiquan; Li, Qun] Zigong Ctr Dis Control & Prevent, Zigong City, Sichuan Provinc, Peoples R China.
[Wan, Kanglin] Chinese Ctr Dis Control & Prevent, Natl Inst Communicable Dis Control & Prevent, POB 5, Beijing 102206, Peoples R China.