The virus prevalence data used in this article has been collected by the Covid Symptom Tracker app (posted by Owl, on 26 March) which allows contributors to track their health. It is also being used by NHS staff to work out local infection rates.

This is an example of an inspired piece of lateral thinking – real science – collecting real data on how this unknown virus is spreading and putting it to use within weeks, rather than all the theorising being done by Public Health England – Owl

Rosamund Urwin and Tom Calver  www.thetimes.co.uk 

Britons who fled to their second homes at the start of the Covid-19 pandemic appear to have taken the virus with them.

Analysis by this newspaper has found that areas with high numbers of holiday homes, including the Lake District, Anglesey and the Cotswolds, now have above-average rates of the coronavirus infection.

People had been urged against travelling to second homes in case they spread the disease and put extra pressure on local hospital and ambulance services.

The virus prevalence data has been collected by the Covid Symptom Tracker app, which allows contributors to track their health. It is also being used by NHS staff to work out local infection rates.

About two million Britons are now using the app, most of whom are healthy. Researchers using this sample estimated that there are 1.9 million people in the UK aged between 20 and 69 who are infected with symptomatic Covid-19.

However, there is a risk that this overstates the extent of the disease, as those with symptoms are more likely to have downloaded the app.

South Lakeland, which includes much of the Lake District, has an infection rate of between 5% and 6%, according to the app. There are 3,866 second homes in the area, about 7% of dwellings, according to data from the Ministry of Housing, Communities and Local Government.

Between 5% and 6% of people on Anglesey, the island off the northwest coast of Wales, and in the Cotswolds are also now infected, according to the app. There are 2,112 second homes in Anglesey, about 7% of residences, and 1,714 second homes in the Cotswolds, about 4% of the total residences.

Professor Tim Spector, the lead researcher for the app, added that there are signs of this trend in other areas too. “It looks like the coasts are more infected than the inner parts of the UK down in Cornwall and Devon — that may be the Londoners’ second home part,” he said.

Nationally, about 4.9% of app users reported symptoms. However, this average is skewed by cities such as London, Glasgow and Birmingham which have become hotspots of the virus.

Both the police and councils have repeatedly told second home owners to stay away. Dafydd Llywelyn, the Plaid Cymru police and crime commissioner for Dyfed Powys, last month described the Covid-19 pandemic as a “national emergency, not a national holiday” and called for travel to a non-primary residence to be banned.

The app was developed by a team at King’s College London in association with the start-up Zoe Global, Guy’s and St Thomas’ NHS Foundation Trust and the NIHR Biomedical Research Centre.

The most commonly reported symptoms include fatigue, described by half of sufferers, and chest pain, a cough and shortness of breath, which were all recorded by more than a quarter of ill respondents. About a fifth reported a hoarse voice and the loss of taste and smell.