Secondary Transmission of Coronavirus Disease from Presymptomatic Persons, China
Weiwei Zhang, Weibin Cheng, Lei Luo, Yu Ma, Conghui Xu, Pengzhe Qin, Zhoubin Zhang
Abstract
C oronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is rapidly spreading across the globe. Some case reports and modeling studies suggest asymptomatic carriage of SARS-CoV-2 plays a role in transmission (1-3). Studies have shown that 30%-59% of SARS-CoV-2 infections are asymptomatic (3,4), which poses tremendous infection control challenges. To control asymptomatic infections, China implemented active case surveillance and enhanced social distancing measures, which include contact tracing, quarantine for key populations, medical observation, and curtailed social activities (5). However, additional information on the characteristics of presymptomatic transmission is needed to develop targeted control and prevention guidance.