The official list of Covid-19 symptoms should be expanded as the existing one could “miss many Covid-19 cases”, experts have argued.

The UK should follow other countries and include a broader range of symptoms, according to a group of scientists. Classic symptoms of Covid-19, listed on the NHS website, are a high temperature, a new continuous cough and/or a loss or change to a person’s sense of smell or taste.

But the most commonly reported symptoms by people taking part in the Office for National Statistics (ONS) Covid-19 Infection Survey are cough, headache and fatigue.

The latest ONS release shows 61% of people who tested positive reported symptoms. Of these, 42% had a cough, 39% reported headache and 38% reported fatigue, according to the ONS. Muscle ache was reported by a quarter of people and 32% reported having a sore throat. Meanwhile a third reported fever and 21% reported loss of smell and 15% reported loss of taste.

A separate study – the Zoe Covid Symptom study – recently reported that a headache, sore throat and runny nose are now the most commonly reported symptoms. These are most likely symptoms of the Delta variant.

What do the experts say?

Writing in the British Medical Journal (BMJ), Dr Alex Crozier and colleagues – including Professor Calum Semple who is a member of Sage – suggest that limiting testing to only people with fever, cough and a change in taste or smell could “miss or delay identification of many Covid cases”.

They suggest this could “hamper efforts to interrupt transmission” of the virus. The group argue that increasing the symptom list could improve Britain’s pandemic response by expanding the criteria for self-isolation and eligibility for symptomatic testing.

The “narrow” case definition “limits” the early detection of contagious people, which restricts the efforts of the Test and Trace programme, they say. Non-traditional symptoms “often manifest earlier”, they added.

The US Centres for Disease Control lists 11 more symptoms than the UK, and the World Health Organisation includes nine more. The testing capabilities are now able to facilitate people with a broader spectrum of symptoms, they added. They say testing people with a single non-specific symptom could overwhelm capacity in the UK, but “combinations of symptoms could be used to help identify more cases sooner without overwhelming testing capacity”.

The authors continue: “The UK’s decision to adopt a narrow case definition was based on ease of communication, avoiding confusion with other infections and preserving testing capacity. This situation is now different — testing capacity is high.

“Covid-19 is associated with a wide range of symptoms. Many patients do not experience the UK’s official case-defining symptoms, initially, or ever, and other symptoms often manifest earlier. Limiting the symptomatic testing to those with these official symptoms will miss or delay identification of many Covid-19 cases, hampering efforts to interrupt transmission.

“Expanding the clinical case definition of Covid−19, the criteria for self-isolation, and eligibility for symptomatic testing could improve the UK’s pandemic response.

The Department of Health and Social Care has been approached for comment by PA Media. We will update this piece if there is a response.