Chills, headaches and loss of appetite should be added to Covid symptoms list, say scientists

Loss of appetite, chills, headaches and muscle aches should be added to the list of coronavirus symptoms to look out for, with scientists saying infected people are suffering a wider range of complaints.

A study of more than one million people by Imperial College found that 60 per cent diagnosed with Covid are not experiencing the four "classic" symptoms – loss of smell and taste, fever and a new persistent cough.

Researchers also found there was variation in symptoms with age. While chills were linked with testing positive across all ages, headaches were reported in young people aged five to 17, appetite loss in those 18 to 54 and 55 plus, and muscle aches in people aged 18 to 54.

Infected five to 17-year-olds were also less likely to report fever, a persistent cough and appetite loss compared with adults.

People in England are currently encouraged to take a Covid test if they have at least one of the "classic" symptoms. Scientists worked out that, based on those symptoms alone, only 50 per cent of cases would ever be tested. But if the additional symptoms were included, this could be improved to three-quarters of symptomatic infections.

Prof Paul Elliott, the 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 UK's new coronavirus variant, first identified in Kent, was linked with a different profile of symptoms. While symptoms were broadly similar, the proportion of people testing positive with a new persistent cough had increased.

Dr Joshua Elliott, from Imperial College's School of Public Health, said: "As the epidemic progresses and new variants emerge, it's essential that we keep monitoring how the virus affects people so that testing programmes meet changing needs.

"We hope that our data will help inform testing guidance and the development of systems which could help better identify people who should take a Covid-19 test based on their symptoms."