Most people who have coronavirus show no symptoms on the day of their test, new research has suggested.
The vast majority of those testing positive did not have any key symptoms when tested – with 77% showing no symptoms. Some 86% did not have a temperature, cough or loss of taste and smell, according to the coronavirus infection survey run by the Office for National Statistics (ONS), which suggests asymptomatic cases could be spreading Covid-19 around the community.
The major study, which tests people every week regardless of whether they have symptoms, has looked at data for 36,061 people tested between the end of April and the end of June.
Some 115 (0.32%) had a positive test result, the study found, of whom 27 (23.5%) were symptomatic and 88 (76.5%) were asymptomatic on the day of the test. But 86.1% of those who tested positive had none of the three main symptoms — cough, fever and loss of taste/smell.
However, scientists have questioned the reliability of the data, since the study only looks at symptoms on the day of testing.
Visit our live blog for the latest updates Coronavirus news live
The researchers are led by University College London’s (UCL) Professor Irene Petersen, who conceded that people may have had symptoms in the days before their test or developed them later, but said the figures suggest large numbers of people may be spreading the virus while asymptomatic.
She told the PA news agency: ‘They may be silent transmitters and they don’t know about it. And so I think that’s a problem.
‘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.’
The scientist said university students are one group who should be tested regularly, and definitely before going home for Christmas.
She continued: ‘I think you could seed a lot of new infections around Christmas – you’re indoors, you sit around the table.
‘Hopefully they can get that (testing) up and running before Christmas, I don’t think they should wait until Christmas.’
The researchers also called for new testing strategies.
Writing in the journal Clinical Epidemiology, they said: ‘Covid-19 symptoms are a poor marker of (Covid) infection.
‘In order to capture “silent” transmission and potentially prevent future outbreaks, test programmes should involve frequent and widespread (Covid-19) testing of all individuals, not just symptomatic cases, at least in high-risk settings or specific locations.’
Professor Petersen added that meat factories were among high-risk settings.
Tim Spector, professor of genetic epidemiology at King’s College London, who leads the Covid Symptom Study (CSS) app, said data from more than four million people who used the app and reported symptoms over a week found that 85% of adults reported fever, cough or loss of taste/smell.
But, he added: ‘The data on children and the over-65s from the CSS app tell us a different story.
Kevin Campbell identifies the two positions Thomas Partey can play at Arsenal
‘Only using the UK’s three classic symptoms will miss around 50% of cases in these important groups that were included in the ONS survey.
‘In a sub-study at King’s College London of twins using antibody testing and the ability to report 20 different symptoms, we showed that only 19% of people are truly asymptomatic.
‘We need to learn from other countries and improve awareness of all the symptoms of Covid-19 to properly control the spread of the virus.’
Paul Hunter, professor in medicine at the University of East Anglia, said the UCL study could not determine the proportion of people with Covid who become symptomatic or remain asymptomatic at some stage during their infection, due to the fact it looked at a fixed time point.
He explained: ‘Anyone who was previously symptomatic and had now recovered or who were currently incubating the infection and would develop symptoms within the following hours would not be included as being symptomatic in this study.’
A Department of Health and Social Care spokesman said: ‘Since the beginning of this pandemic we have prioritised testing for health and care workers to ensure all NHS staff have consistent access to testing.
‘NHS staff with symptoms can access testing as a priority and staff in outbreak areas can access tests if they are asymptomatic. We will continue to expand testing availability as our capacity expands to 500,000 tests a day by the end of October.’
Previous studies have suggested that around 80% of people who caught coronavirus were given it by asymptomatic carriers.
Get in touch with our news team by emailing us at webnews@metro.co.uk.
For more stories like this, check our news page.
MORE: Students hold Covid parties only for those who have tested positive
source https://metro.co.uk/2020/10/08/most-people-with-coronavirus-have-no-symptoms-when-they-take-a-test-13389009/