Covid-19 is linked to a wider set of symptoms than scientists previously thought, a new study has suggested.
The findings are based on swab tests and questionnaires from more than one million people in England, collected between June 2020 until last month as part of Imperial College London’s React study.
What are the extra symptoms?
Chills, a loss of appetite, headaches and muscle aches could all be additional symptoms of coronavirus, according to the study.
This is in addition to the ‘classic’ three symptoms of Covid-19 that are already included in NHS guidance. These are:
- loss of taste and smell
- a fever
- a new persistent cough
Having any of the classic symptoms, or the four additional ones, either along or in combination, was associated with infection with coronavirus.
Researchers found that the more symptoms people showed, the more likely they were to test positive for the virus.
However, around 60 per cent of infected people did not report any symptoms in the week leading up to their test.
Symptoms vary by age
Findings also identified variation in symptoms based on people’s age, with some being more common among younger age groups.
Chills were linked with people who tested positive across all ages, headaches were reported most among young people aged between five and 17, while appetite loss was more common in 18 to 54 year olds, and those aged 55 and over.
Muscle aches were mostly reported in people aged between 18 and 54.
Infected five to 17 year olds were also less likely to report fever, a persistent cough and appetite loss compared with adults, according to the study.
Calls to recognise more symptoms
People in the UK are currently encouraged to get a Covid-19 test if they have any of the classic symptoms.
It is estimated that if everyone who experiences the classic symptoms was tested, it would pick up around half of all symptomatic infections. However, if the additional symptoms were included, this could be improved to three-quarters of symptomatic infections.
Professor Paul Elliott, director of the React programme at Imperial, said: “These new findings suggest many people with Covid-19 won’t be getting tested – and therefore won’t be self-isolating – because their symptoms don’t match those used in current public health guidance to help identify infected people.
“We understand that there is a need for clear testing criteria, and that including lots of symptoms which are commonly found in other illnesses like seasonal flu could risk people self-isolating unnecessarily.
“I hope that our findings on the most informative symptoms mean that the testing programme can take advantage of the most up-to-date evidence, helping to identify more infected people.”
The study, which has not yet been peer-reviewed, also looked at whether the emergence of the UK’s new coronavirus variant, first identified in Kent, was linked with a different profile of symptoms.
Researchers looked at self-reported symptoms and swab test results collected for the React study in November to December, when Public Health England (PHE) estimated the variant made up around 16 per cent of infections.
They compared this with similar data collected in January, when an estimated 86 per cent of infections were from the variant.
While symptoms were found to be broadly similar, loss or change to one’s sense of smell was less predictive of having Covid-19, but the proportion of people testing positive with a new persistent cough appeared higher, in keeping with findings from the Office for National Statistics.