Coronavirus testing may only be detecting a third of UK cases – health expert

By Tom Pilgrim, PA

The UK’s coronavirus testing regime may only be picking up a third of cases in the community due to people being asymptomatic, a health expert has said.

On Wednesday, the number of confirmed daily Covid-19 cases across the country was reported to have risen to more than 6,000 for the first time since May.

But Dr Julian Tang, honorary associate professor of respiratory sciences at the University of Leicester, suggested there could be up to an additional 12,000 cases not yet being identified.

His comments came as Health Secretary Matt Hancock estimated fewer than 10,000 a day are contracting the virus.

Dr Tang said findings from the Real-Time Assessment of Community Transmission (React-1) study, a large population survey examining the prevalence of coronavirus in England, showed that “up to two-thirds (60-70%) of Covid-19 cases may be asymptomatic”.

He said that if there are 6,000 known daily cases then there could be “additional” infections of around 12,000 “we haven’t identified yet”.

Dr Tang added: “So the symptomatic cases that go for PCR (polymerase chain reaction) testing may only constitute just one-third of Covid-19 cases.”

He also highlighted that the React-2 study of antibody surveillance results up to the end of June indicated there were around 3.4 million Covid-19 cases with antibodies to the virus in the community, whereas PCR-based testing showed only around 280,000 cases in the UK.

Dr Tang said: “Hence just based on these React studies alone, there are many more Covid-19 cases in the community, not being tested by PCR acutely, that can be spreading the virus.

“This is a very worrying trend and it remains to be seen how the BAME (black, Asian, and minority ethnic) populations are going to be affected (though likely in a similar way).