如下 其实小哥哥群里的坡上小护士们也说了他们院也是采取30分界线A separate analysis of a cohort of 73 patients admitted to the National Centre for Infectious Diseases, Singapore demonstrated that SARS-CoV-2 could not be cultured when the Ct value was ≥30, or after day 11 of illness. via National Centre for Infectious Diseases and Chapter of Infectious Disease Physicians, Academy Medicine of Singapore. Period of infectivity to inform strategies for de-isolation for COVID-19 patients, 23 May 2020. Available at: https://www.ncid.sg/Documents/ Period%20of%20Infectivity%20Position%20Statementv2.pdf. Accessed on 23 May 2020. 坡上的阳性标准是小于等于30 兔子的标准是小于37 37-40重测 大于40才是阴性