[1] Guangxi Zhuang Autonomous Reg Ctr Dis Control & Pr, Food Safety Monitoring & Evaluat Dept, Nanning, Peoples R China
[2] Prince Songkla Univ, Fac Med, Dept Epidemiol, Hat Yai 90110, Songkhla, Thailand
[3] Fourth Peoples Hosp Nanning, Infect Dis Dept, Nanning, Peoples R China
[4] Guiping Ctr Dis Control & Prevent Guiping CDC, Infect Dis Control & Prevent Dept, Guigang, Peoples R China
[5] Guiping Peoples Hosp, Matern Dept, Guigang, Peoples R China