More than half of people with strong Covid infection are asymptomatic, new figures show

New analysis of infected people in the community highlights risk of asymptomatic transmission of Coronavirus

More than half of people with a strong Covid infection did not report any of the major symptoms, new figures from the Office for National Statistics have revealed.

This underlines the risk of people spreading the virus without knowing they are infected which is thought to be one of the main ways the coronavirus pandemic has been able to spread so easily around the world.

The ONS said 53 per cent of people with a strong positive, or high viral load, between December and March did not report having any symptoms compared to 47 per cent who did. It excluded patients likely to be at the start of their infection when transmission and symptoms are thought to be less likely.

Fatigue, headache and cough were the most commonly reported symptoms amongst people who had a strong positive test for Covid-19.

Sarah Crofts, senior statistician for the ONS Covid-19 Infection Survey said: “Our analysis today highlights the range of symptoms people can experience with Covid-19.”

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She said: “The classic symptoms of fatigue, headache and cough are still the most commonly reported by those infected with the virus, while only around 1 in 5 experience loss of taste or smell only.

“Around half of those we tested did not report any symptoms even whilst having high levels of the virus present in their body. This underlines that people in the community may unknowingly have the virus and potentially transmit it to others.”

“It is vital we continue to measure infection levels in the population and collect information on symptoms so we can identify any changes that may otherwise go undetected.”

During March, a total of 36 per cent of people reported the classic symptoms associated with Covid-19, with 28 per cent reporting a cough, 20 per cent reporting a fever and 12 per cent describing a shortness of breath.

A loss of taste and smell was reported by 14 per cent of patients. Six per cent also reported diarrhoea and adbominal pain.

The strength of the infection was determined by how quickly the virus was detected in laboratory tests. The quicker detection means the patient may have a higher viral load in the body resulting in a stronger positive result.

Some patients with a high result were excluded from the survey as this can include people who are at the early stage of the infection, or presymptomatic.

The ONS infection survey is based on a sample of private households and excludes hospitals or care homes.

In its latest weekly survey, the ONS estimated 148,000 people in the community had Covid-19.