- A symptom-based and epidemiology-based screening process was ineffective in detecting all SARS-CoV-2 cases.
- Persons who have no fever and no signs or symptoms of respiratory infection can potentially shed SARS-CoV-2. The proportion of asymptomatic cases among individuals who tested positive for SARS-CoV-2 is around 17.9%.
- Since the viral loads between asymptomatic and symptomatic patients are comparable, transmission of SARS-CoV-2 by asymptomatic cases may be possible.
- Hoehl S, Rabenau H, Berger A, et al. (March 16, 2020). Evidence of SARS-CoV-2 Infection in Returning Travelers from Wuhan, China. N Engl J Med.
- Mizumoto K, Kagaya K, Zarebski A, Chowell G. (March 19, 2020). Estimating the asymptomatic proportion of coronavirus disease 2019 (COVID-19) cases on board the Diamond Princess cruise ship, Yokohama, Japan. Euro Surveill.
- Zou L, Ruan F, Huang M, Liang L, Huang H, Hong Z, et al. (March 19, 2020). SARS- CoV-2 Viral Load in Upper Respiratory Specimens of Infected Patients. N Engl J Med. https://www.nejm.org/doi/full/10.1056/NEJMc2001737