J Epidemiol Community Health . Role of presymptomatic transmission of COVID-19: evidence from Beijing, China

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J Epidemiol Community Health


. 2020 Aug 27;jech-2020-214635.
doi: 10.1136/jech-2020-214635. Online ahead of print.
Role of presymptomatic transmission of COVID-19: evidence from Beijing, China


Yi Zhang ^{# 1} , David Muscatello ^{# 2} , Yi Tian ¹ , Yanwei Chen ¹ , Shuang Li ¹ , Wei Duan ¹ , Chunna Ma ¹ , Ying Sun ¹ , Shuangsheng Wu ¹ , Lin Ge ³ , Peng Yang ¹ , Lei Jia ¹ , Quanyi Wang ⁴ , Chandini Raina MacIntyre ^{2 5}



Affiliations

• PMID: 32855261
• DOI: 10.1136/jech-2020-214635

Abstract

Background: The presymptomatic transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been documented in limited clusters, and it is predicted through modelling. However, there is a lack of evidence from observations with a large sample size.
Methods: We used data from meticulous contact tracing of people exposed to cases of SARS-CoV-2 to estimate the proportion of cases that result from the presymptomatic transmission of the virus in Beijing during January 2020 and February 2020.
Results: The results showed that presymptomatic transmission occurred in at least 15% of 100 secondary COVID-19 cases. The earliest presymptomatic contact event occurred 5 days prior to the index case's onset of symptoms, and this occurred in two clusters.
Conclusions: The finding suggested that the contact tracing period should be earlier and highlighted the importance of preventing transmission opportunities well before the onset of symptoms.

Keywords: Communicable diseases; control of diseases; public health policy.