[1] Zhengzhou Univ, Coll Publ Hlth, Zhengzhou, Peoples R China
[2] Chinese PLA Ctr Dis Control & Prevent, Dept Disinfect & Infect Control, Beijing, Peoples R China
[3] China Med Univ, Inst Neurol, Shenyang, Peoples R China
[4] Chinese PLA Ctr Dis Control & Prevent, 20 Dongda St, Beijing, Peoples R China