Presymptomatic Transmission of SARS-CoV-2 — Singapore, January 23–March 16, 2020
By W. Wei, Zongbin Li, Calvin J. Chiew, S. E. Yong, M. Toh, V. Lee. MMWR. Morbidity and mortality weekly report, 2020
945 citations recorded by the source corpus.
Presymptomatic transmission of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), might pose challenges for disease control. The first case of COVID-19 in Singapore was detected on January 23, 2020, and by March 16, a total of 243 cases had been confirmed, including 157 locally acquired cases. Clinical and epidemiologic findings of all COVID-19 cases in Singapore through March 16 were reviewed to determine whether presymptomatic transmission might have occurred. Presymptomatic transmission was defined as the transmission of SARS-CoV-2 from an infected person (source patient) to a secondary patient before the source patient developed symptoms, as ascertained by exposure and symptom onset dates, with no evidence that the secondary patient had been exposed to anyone else with COVID-19. Seven COVID-19 epidemiologic clusters in which presymptomatic transmission likely occurred were identified, and 10 such cases within these clusters accounted for 6.4% of the 157 locally acquired cases. In the four clusters for which the date of exposure could be determined, presymptomatic transmission occurred 1-3 days before symptom onset in the presymptomatic source patient. To account for the possibility of presymptomatic transmission, officials developing contact tracing protocols should strongly consider including a period before symptom onset. Evidence of presymptomatic transmission of SARS-CoV-2 underscores the critical role social distancing, including avoidance of congregate settings, plays in controlling the COVID-19 pandemic.
Subfields: Infectious Diseases, Modeling and Simulation, Pulmonary and Respiratory Medicine
View Paper: https://www.semanticscholar.org/paper/1f33eedd3001e232173d0dc3b867d4d5630afcb3
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In Infectious Diseases
In Pulmonary and Respiratory Medicine
Citations in the corpus
- COVID-19: Prevention and control measures in community (2020, background): “Studies have been conducted that support the infectiousness of SARS-CoV-2 in the presymptomatic stage; social distancing is thus of critical importance in establishing control over the pandemic[2].”
- Coronavirus (COVID-19) (2020, background): “Although respiratory aerosol spread was initially controversial, a committee of the National Academy of Sciences has subsequently concluded there is some limited evidence that it is also spread by respiratory aerosols [27-35]; other evidence of aerosol spread is rapidly accruing, with increasing opi”
- Coronavirus Disease 2019 in Children — United States, February 12–April 2, 2020 (2020, background): “Social distancing and everyday preventive behaviors remain important for all age groups as patients with less serious illness and those without symptoms likely play an important role in disease transmission (6,7).”