The number of “silent carriers” – people who are infected by the new coronavirus but show delayed or no symptoms – could be as high as one-third of those who test positive, according to classified Chinese government data seen by the South China Morning Post.
That could further complicate the strategies being used by countries to contain the virus, which has infected more than 300,000 people and killed more than 14,000 globally.
More than 43,000 people in China had tested positive for Covid-19 by the end of February but had no immediate symptoms, a condition typically known as asymptomatic, according to the data. They were placed in quarantine and monitored but were not included in the official tally of confirmed cases, which stood at about 80,000 at the time.
Scientists have been unable to agree on what role asymptomatic transmission plays in spreading the disease. A patient usually develops symptoms in five days, though the incubation period can be as long as three weeks in some rare cases. . .
A growing number of studies are now questioning the WHO’s earlier statement that asymptomatic transmission was “extremely rare”. A report by the WHO’s international mission after a trip to China estimated that asymptomatic infections accounted for 1 to 3 per cent of cases, according to a European Union paper. (Read more from “Report: China Concealed 43,000 Confirmed COVID-19 Cases” HERE)