Individuals who have contracted coronavirus but do not exhibit symptoms are not driving the spread of the virus, World Health Organization officials said Monday in a significant development regarding the pandemic.
Dr. Maria Van Kerkhove, head of WHO's emerging diseases and zoonosis unit, made the announcement at a news briefing from the United Nations' Geneva headquarters:
"We have a number of reports from countries who are doing very detailed contact tracing. They're following asymptomatic cases. They're following contacts. And they're not finding secondary transmission onward. It's very rare. And much of that is not published in the literature ...
We are constantly looking at this data and we are trying to get more information from countries to truly answer this question. It still appears to be rare that an asymptomatic individual actually transmits onward."
If asymptomatic spread proves to not be a main driver of coronavirus transmission, the policy implications could be tremendous. A report from the U.S. Centers for Disease Control and Prevention published on April 1 cited the "potential for presymptomatic transmission" as a reason for the importance of social distancing.
"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," the CDC study said.