CDC director warns 25% of new coronavirus infections may be asymptomatic

Robert Redfield, director of the Centers for Disease Control and Prevention (CDC), said 25 percent of people infected with the new coronavirus may be asymptomatic, but some of them will still transmit the virus, according tomedia reports. At the same time, the CDC has released a new report tracking transmission groups, which suggests that infected people may become contagious one to three days before any symptoms appear.

CDC director warns 25% of new coronavirus infections may be asymptomatic

Robert Redfield (right)

Normally, the symptoms of new coronavirus infection will be more obvious, such as dry cough, fever, etc. , but now there is a larger problem, that is, how many people infected with the virus after no symptoms?

CDC Director Robert Redfield said in a recent interview with NPR that the CDC believes that nearly a quarter of new coronavirus infections may not have any symptoms. More worryingly, these invisible carriers are highly likely to be contagious and unknowingly spread the virus over a period of time. “One of the basically confirmed information we have now is that a significant number of infected people are still actually asymptomatic. This rate can be as high as 25%. This is important because some people may not have any symptoms that can cause transmission, and we have learned that they actually cause transmission. “

Without large-scale non-random testing, it is almost impossible to know exactly how many cases of asymptomatic new coronavirus may be spreading in the community. Redfield said the CDC is considering proposals to urge people to wear masks universally.

“…… You can look at masks in two ways… Is the mask used to protect me or… If I wear a mask, can it protect others from me? “I can tell you that as we speak, the data and whether it helps (prevention) are being actively evaluated.” “

While asymptomatic propagation has proved challenging, CDC researchers are becoming more aware of pre-symptom asymptomatic transmission problems. Pre-symptom transmission consists mainly of a period during which a person may be contagious before he or she begins to exhibit symptoms.

A new report from Singapore’s Ministry of Health, published by the CDC, shows that pre-symptom patients spread before symptoms occur one to three days before they appear. The report concludes: “The likelihood of transmission before SARS-CoV-2 appears increases the challenge of neo-coronavirus control measures, which are based on early detection and isolation of people with symptoms.” The extent of this effect depends on the extent and duration of the transmission, which has not been clearly confirmed to date, before the patient is pre-symptomatic. “

Between the unknown number of asymptomatic carriers and the apparent pre-symptom transmission potential, Redfield stresses the importance of social distance as the most powerful weapon in the fight against the spread of the new coronavirus. Unless people can clearly determine who is infected with the new coronavirus and when they are likely to be most contagious, maintaining social distance is currently the best strategy to contain the virus.