[Asymptomatic and pre-symptomatic cases of COVID-19 contribution to spreading the epidemic and need for targeted control strategies].

Wu, Z Y

The asymptomatic carrier state of COVID-19 has become a topic of concern for preventing a possible epidemic rebound. This review describes and defines the COVID-19 asymptomatic carrier state and outlines methods for identifying counting and reporting these cases. The author elaborates that the asymptomatic carrier state can be further divided into asymptomatic infection and pre-symptomatic infection after extended follow-up based on the nature of disease progression. The author presents the limited available data about infectiousness of asymptomatic and pre-symptomatic cases and their possible contributions to the overall epidemic of COVID-19 observed so far in China. Challenges of a possible second epidemic wave of COVID-19 caused by asymptomatic and pre-symptomatic cases are discussed and suggestions for control strategies and scientific research are provided.