Presymptomatic Transmission of SARS-CoV-2 - Centers for disease control and prevention – MMWR
By: Wycliffe E. Wei et al.
- This report describes the transmission of a number of asymptomatic patients in 7 clusters of COVID 19 patients in Singapore.
- The evidence of presymptomatic transmission in Singapore, in combination with evidence from other studies supports the likelihood that viral shedding can occur in the absence of symptoms and before symptom onset.
- This study identified seven clusters of cases in which presymptomatic transmission of COVID-19 likely occurred.
- 157 of 243 cases in Singapore as of March 16, were locally acquired.
- 10 of the 157 (6.4%) locally acquired cases attributed to presymptomatic transmission.
- These findings also suggest that to control the pandemic it might not be enough for only persons with symptoms to limit their contact with others because persons without symptoms might transmit infection.
- Finally, these findings underscore the importance of social distancing in the public health response to the COVID-19 pandemic, including the avoidance of congregate settings.