GAN Xiaohua *; SHI Yongfa; LIU Guangyuan; et al. * Public Health Bureau of Cuiping District in Yibin City of Sichuan Province; Yibin 644000; China;

• 四川省宜宾市翠屏区卫生局;四川省宜宾市翠屏区人民医院;