A study of over a million people in England has revealed additional symptoms linked with COVID-19.
In addition to the classic symptoms of loss of sense of smell and taste, fever and new persistent cough, the latest findings from the ongoing REal-time Assessment of Community Transmission (REACT-1) programme, led by Imperial and carried out in partnership with Ipsos MORI, suggest a wide range of other symptoms associated with COVID-19.
Swab tests and questionnaires collected between June 2020 and January 2021 as part of REACT showed that among these other symptoms, chills, loss of appetite, headache and muscle aches were together most strongly linked with infection, alongside the four classic symptoms. Having any of these other symptoms or the classic ones, either alone or in combination, was associated with infection. People with more symptoms were more likely to test positive. The study also found that there was variation in symptoms with age.
Based on these new findings, the researchers estimate that current Pillar 2 testing would pick up around half of all symptomatic infections if everyone eligible were tested. But 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 research also explored whether the emergence of the new UK variant was linked with a different profile of symptoms.
While symptoms were broadly similar, in January compared with November-December, loss or change to sense of smell was less predictive of having COVID-19, whereas the proportion of people testing positive with a new persistent cough appeared to be increased.
