Tracker app suggests coronavirus was spreading in UK weeks before first case was spotted and claims we had already passed peak infection on April 1

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A coronavirus tracking app has suggested the disease arrived in the UK in January, well before the first cases were detected.

COVID Symptom tracker, designed by scientists at King's College London, asks its 2.6million users to report their symptoms daily, even if they are well, in order to map the disease's spread.

Hundreds of contributors have, however, also admitted to suffering from Covid-like symptoms soon after the new year with a few even saying they thought they had the disease in late December, the Professor Genetic Epidemiology at King's and scientist working on the app, Tim Spector, has said.

Although the cases are untested, the reports suggest the virus gained a foothold in the UK long before the first case was identified on British soil on January 31, when two Chinese people in York tested positive for the virus.

The app's data has also suggested that the lockdown measures have worked, with estimated cases dropping by more than 80 per cent to 354,690 today since a peak of 2.1million on April 1.

It is hoped that technology including apps such as this will allow the UK to return to a semblance of normality.

NHSX, the health service's 'digital transformation' arm, is working on its own contact tracing app that will alert users when they have been near an individual who has later presented symptoms of the disease.

The app will need 60 per cent of the population - or 40 million people - to download it in order to be effective. It will reportedly be available 'within weeks'.

The app has estimated there are 354,690 cases of coronavirus in the UK today, based on data from 2.6 million users, a drop of more than 80 per cent from April 1

At the height of the outbreak the app estimates there were more than two million cases in the UK. The government's coronavirus figure has not risen above 148,377. The graph does not display data from January as the team did not start collecting daily data until late March. Some respondents have told the researchers through the app that they had symptoms in January

After the lockdown began on March 23 the outbreak peaked on April 1, according to the app

Since then UK cases have been in freefall and dropped by more than 80 per cent, suggesting the government's social distancing programme has been highly effective

Professor Tim Spector, at King's College London, said 'hundreds' of users have reported suffering from Covid-like symptoms in early January and a few in December

Prof Spector told the Sunday Times: 'The reports I am getting are from people who were ill from early January onwards and strongly suggest they had Covid-19 but were not recognised as such.'

'What's impressive is the sheer volume of the reports. We're getting hundreds of people using our app telling us that they developed something soon after the new year.'

Britain's official coronavirus case count did not rise above 100 until March 6, and did not reach 1,000 until March 14. The current case count is at 148,377, well below the app's estimate of 354,690.

Users are asked to report their condition to the app, developed by London-based firm ZOE Global, every day.

They are first asked whether they have had a test for Covid-19, followed by whether they are feeling unwell. Those that say they don't feel quite right are asked to enter their symptoms including fever, cough, headache, shortness of breath, sore throat, loss of smell and hoarse voice.

The data gathered, which includes geographical location, is then analysed to produce an estimate of the number of coronavirus cases in the UK. 

It has identified four hotspots for the virus in Pendle and Hyndburn, Lancaster, Nuneaton, outside Coventry, and Blaenau Gwent, Wales, where it estimates two to three per cent of inhabitants have the virus.

No hotspots have been identified in London, at the epicentre of the UK's outbreak.

The research is backed by the Royal College of Physicians, Royal College of Surgeons alongside other medicinal bodies.

NHS Scotland and NHS Wales have also endorsed the app, but NHS England has not. It is thought they are holding back in order to endorse NHSX's app when it is released in a matter of weeks. 

The app estimates the number of coronavirus sufferers peaked on April 1 before declining significantly during lockdown

The COVID Symptom Tracker works by taking people through a questionnaire about how they are feeling and whether they have the typical symptoms of coronavirus

Between April 12 and April 19 the app used its data to predict at least one per cent of inhabitants in most areas of the UK were suffering from coronavirus

The research means people who believed they had the disease in January but were never tested could have been correct.

Daren Bland, 50, from Maresfield, East Sussex, who visited the Ischgl resort in Austria from January 15 to 19.

He is understood to have joined three friends for a holiday on the slopes before contracting Covid-19 and bringing it home to his wife and children.

The ski resort has been dubbed a 'breeding ground' for coronavirus in Germany after it was connected to hundreds of cases identified in Denmark, Iceland, Sweden, Austria and Germany.

British businessman Steve Walsh caught the virus between January 20 to 23 at a conference in Grand Hyatt, Singapore, before returning to the UK and unknowingly spreading it to at least 11 other Britons.

Many others have also reported experiencing Covid-like symptoms, but their cases were never confirmed due to a limited testing capacity in the UK.

A study from Oxford University published last month claimed the virus was spreading in the UK for a month before it was first identified.

Scientists modelled coronavirus cases to estimate that it was spreading in the UK by mid-January at the latest.

There were about 17 direct flights between Wuhan and the UK between the new year and January 24 alone, alongside many to and from Italy.

An Italian study has estimated coronavirus was circulating in Lombardy more than a month before it was officially identified on February 21 in Codogno.

The data suggests patients such as Daren Bland, 50, from East Sussex, should be counted among the earliest coronavirus cases. He suffered coronavirus-like symptoms following a trip from January 15 to 19. Steve Walsh caught the virus in Singapore between January 20 to 23

The number of deaths from coronavirus in the UK increased by 813 yesterday, the sixth highest daily increase since the pandemic began. The number of infections rose by 4,913

Authorities have been looking at ways to harness technology in order to get the UK back to work.

NHSX has been working on a contact tracing app that will alert users when they have been near someone that has developed symptoms of coronavirus.

It will ask them to isolate, and later alert the individual if the person they have been near has tested positive. All the information is anonymous. 

NHSX has been working on the app, that uses bluetooth, alongside Google and Apple, which run the two main smartphone operating systems.

Matt Hancock said at the Downing Street news conference on April 12: 'If you become unwell with the symptoms of coronavirus you can securely tell this new NHS app and the app will then send an alert anonymously to other app users that you've been in significant contact with over the past few days, even before (they) have symptoms so that they know and can act accordingly.

'All data will be handled according to the highest ethical and security standards and would only be used for NHS care and research and we won't hold it any longer than it's needed.'

The app was tested at an RAF base in North Yorkshire this week, ahead of its expected roll out to the public. 

An NHS contact-tracing app would only completely stop the spread of coronavirus if 80 per cent of current smartphone owners use it, researchers have warned

The UK government has continued to race to meet its coronavirus testing target of 100,000 today, as it faces ever louder calls to announce a plan to end the lockdown.

Prime Minister Boris Johnson is expected to return to Downing Street on Monday following a two week break at Chequers to recover from the virus.

He spent a week in Guys and St Thomas' Hospital, London, and three days in intensive care fighting off the disease. 

UK Foreign Secretary Dominic Raab rejected calls for an earlier easing of the coronavirus lockdown today, stressing the government aimed to move cautiously to avoid a second wave.

He has refused to reveal details of how the UK will exit lockdown, despite the Welsh and Scottish ministers publishing their strategies.

Nicola Sturgeon has hinted that Scotland may lift its lockdown at a different pace to the rest of the UK.

It has also been announced that the UK will begin asking new arrivals to quarantine for 14 days, after letting at least 15,000 people in every week without checks. 

Contact tracing app to be released in weeks could prevent one Covid-19 infection for every one or two who download it says Oxford University professor

A contact tracing app could prevent one Covid-19 infection for every one to two users who download it, an expert advising the government has said.

Professor Christophe Fraser, from Oxford University's Big Data Institute, heaped praise on the app but said 60 per cent of the UK population - or 40 million people - would need to download it for it to prove effective.

NHSX has been working with Google and Apple to develop the phone app, which should be available 'within weeks'. It was tested at an RAF base in North Yorkshire this week.

The app could hold the key to bringing the UK out of lockdown and back to normality.

Professor Christophe Fraser, from Oxford University's Big Data Institute, said 60 per cent of the UK population will need to sign up to the app for it to prove effective. Matt Hancock has supported the app's roll out

Professor Fraser pictured speaking about the app on the Andrew Marr show today

Prof Fraser told BBC One's The Andrew Marr Show that traditional contact tracing methods would not be as effective as the NHS app.

'We found that when we projected over the next three months, for every one to two users who download the app and who adhere to instructions, you'll prevent one infection,' he said.

'For this intervention alone to stop resurgence of the epidemic, about 60% of the population would have to use the app.

'Now that number may be a bit smaller if there are other interventions going on, which we hope there will be, social distancing, large community testing, and indeed manual contact tracing.'

Prof Fraser said the app addresses the problem that around 50 per cent of transmissions occur before a person shows symptoms - calling it a 'very rapidly transmitted virus'.

He said: 'The app is solving a specific problem, which is how do you get the message that you're at risk and empower you to take measures to protect your friends, your family, your colleagues and the people you have been in contact with.'

Experts are aiming to release the NHS app 'within weeks', he told the programme, while a configuration is being developed for healthcare staff who could be exposed to Covid-19 whilst at work.

Asked if he thought pursuing a contact tracing app earlier could have saved lives, Prof Fraser said: 'I think so. I worked on the SARS epidemic in 2003 and testing and tracing is really a cornerstone of how you stop a serious infection.

'And I do think that strategy scaled up is tremendously effective.'

Nevertheless, the app coupled with social distancing efforts would still help to slow the spread of COVID-19 and put off a second lockdown period. In fact, the team predicts that a contact-tracing app could 'prevent approximately one infection for every one or two users of the app'

An NHS contact-tracing app would only completely stop the spread of coronavirus if 60 per cent of current smartphone owners use it, researchers have warned

He estimated that between 3 per cent and 10 per cent of the population could now have had the disease.

'There's uncertainty around this but I would say nationally, somewhere between sort of three and maybe up to 10 per cent of the population would have had coronavirus by this stage,' he said.

'We're still waiting for the definitive studies based on immunological assays, but this is based on our understanding base of the spread of coronavirus.'

Asked if it could be 'several million people, up to six million', he replied: 'That kind of figure - probably a bit less.' 

Pictured above is a contact-tracing app being used in Germany to halt the spread of coronavirus