LONDON

Over 85% of people who tested positive for the novel coronavirus in the UK did not have any of the established symptoms of the disease when they took the test, a new study released on Thursday found.

The research was carried out by UCL using data from the Office for National Statistics, and found that on the day of their test 86.1% of people infected between April and June had none of the symptoms usually associated with the virus, such as a cough, fever, or loss of taste and smell.

The research raised fears of “silent transmission,” and highlighted the need for more widespread testing.

“At the moment, the focus is on people who have symptoms, but if you are not catching all those who are asymptomatic or presymptomatic it may be really difficult to get outbreaks down in time, before they get out of control,” Irene Petersen, a professor of epidemiology and health informatics at UCL who led the study, was quoted by the Guardian as saying.

“They may be silent transmitters and they don't know about it. And so I think that's a problem,” she told Sky News.

“You may have a lot of people who are out in the society and they're not self-isolating because they didn't know that they are positive.”

Researchers stressed that those who tested positive could still have developed symptoms later on, but by then they could have passed on the disease without being aware of it.

The research analyzed 36,000 people tested for coronavirus between April and June.

Of these, 115 – 0.32% – tested positive, and of those just 27 – or 23.5% – had symptoms of any kind, and 88 – or 76.5% – were asymptomatic.

When the symptoms were narrowed to the three most widely known ones – a cough, fever, or loss of taste and smell – the number dropped to 16, or 13.9%, meaning 86.1% who tested positive did not have the main symptoms.

“There will be great public health benefit in terms of reducing transmission if we can reliably identify asymptomatic individuals and they then self-isolate,” the Guardian quoted Patrick Maxwell, head of the school of clinical medicine at Cambridge, as saying.