Department of Orthopaedics Sichuan University West China Hospital Chengdu 610041 Sichuan Province China;
College of Life Sciences Fujian Normal University Fuzhou 350117 Fujian Province China;
Anxi AIER Eye Hospital(AIER EYE Hospital Group) Anxi 362400 Fujian Province China;
COVID-19; SARS-CoV-2; Coronavirus; Pandemic; Testing density;