Coronavirus: many infections spread by people yet to show symptoms - scientists

Source: The Guardian

Coronavirus: many infections spread by people yet to show symptoms (est: 45% to 85%)

An analysis of infections in Singapore and Tianjin in China revealed that two-thirds and three-quarters of people respectively appear to have caught it from others who were incubating the virus but still symptom-free.

Researchers in Belgium and the Netherlands drew on data from outbreaks in Singapore and Tianjin to work out the "generation interval" for Covid-19. The generation interval is the time between one person getting infected and them infecting another. The figure is valuable for estimating the speed at which an outbreak will unfold.

The mean generation interval was 5.2 days in the Singapore cluster and 3.95 days in the China cluster, according to the analysis which is under review at an infectious disease journal. The scientists went on to calculate what proportion of infections were likely spread from people who were still incubating the virus and had yet to develop symptoms.

There are uncertainties in the figures because the scientists did not have precise information on who infected whom in the two clusters of disease. But even the lowest estimates show there was substantial transmission of coronavirus from people who had yet to fall ill.

In the Singapore cluster, between 45% and 84% of infections appeared to come from people incubating the virus. In China, the figures ranged from 65% to as much as 87%.

Read more: https://www.theguardian.com/science/2020/mar/12/coronavirus-most-infections-spread-by-people-yet-to-show-symptoms-scientists