9,900 new COVID cases across England daily – New estimates from symptom tracker

This new figure for England is over three times greater than the ONS figure for the whole UK of circa 3,000 daily confirmed cases . The latter, of course, is limited to the availability of testing and the fact that it also relies on individuals coming forward to seek tests. Remember the mantra “Most will only get a mild form of the disease”. The novel Covid-19 is associated with a wider range of symptoms than high fever and cough.

Tim Spector has released new work in which his symptom estimates have been combined with targeted swab testing, provided by Department of Health and Social Care, to give an estimate of Covid-19 infection rates. Estimates are not only given Nationally but for English Regions.

Surprisingly, this work has to rely on crowd funding to continue . This has raised £860K so far against a target of £1M. A case of “Not Invented Here” as far as Public Health England is concerned?

Owl has always taken the view that this work was providing the most useful estimates of the distribution and progress of the pandemic in UK. For example, it showed that infection rates started falling around 1 April. Government data at that time was inconsistent and confined to measuring hospital admissions. Admissions of serious cases lag initial infections by at least 8 days. Government data is still lagging because most test turnarounds take days.

Tim Spector’s work shows that the South West has a marginally lower infection rate than London, this is not the received wisdom in Whitehall. The online article contains more information and acknowledgements than given below. Skip the explanation of the method to the end if you just want the results.

covid.joinzoe.com /post/covid-cases-england

By combining COVID swab testing with data from the COVID Symptom Study app, we are able to estimate the number of new daily COVID cases within the community

Data from the COVID Symptom Study suggests there are currently 9,900 daily new cases of COVID across England.

This excludes care homes [*] and asymptomatic cases. These results are based on a group of 980,000 people using our app, of whom 18,000 were invited to do COVID swab tests after showing early signs of coronavirus infection. These tests were provided by the Department of Health and Social Care, either via a self-administered home test kit or regional testing centres.

Developed by health technology company ZOE, the COVID Symptom Study app now has more than 3.6 million users across the UK, US and Sweden, making it the largest ongoing coronavirus study in the world.

All areas of England are seeing new cases, but levels in the North are around twice those in the South. These figures give an up to date view of COVID infection rates, unlike deaths which lag by about a month.

How we are calculating these figures

The figure of 9,900 was calculated using swab testing and app symptom data collected over the last two weeks (2-15 May), from users of all ages and spread throughout England. This makes it the first time that digital health data from a very large population has been combined with physical COVID swab tests to create an accurate view of what COVID looks like in the population on a day-by-day basis.

These results were based on 980,000 people contributing digitally of whom 18,000 received rapid testing for COVID infection in the two weeks from 2-15 May. Those invited for testing include individuals using our app who have reported being healthy for at least nine days before they log new symptoms for the first time. We have aggregated these two weeks in order to get a large enough population to allow us to estimate regional variations, as well as overall levels in England.

Facilitating a safe exit from lockdown

The ability to accurately estimate the number of new daily COVID cases within the community via technology can be a critical part of the UK’s fight against COVID, alongside ONS surveys that report weekly or monthly based on random swab testing or changes in antibody testing.

With all eyes on “r”, it is critical that the number of daily new cases does not rise as we ease out of lockdown. The COVID Symptom Study enables over 3 million people to contribute, and so provides a more current picture of how the COVID situation is changing. It can also highlight regional differences and show potential increases in the virus before other detection methods.

Daily new cases across England

The map below shows the rates across the different regions of England. The data for each region is presented as a range, because the absolute infection rates are now low. These estimates show a two fold difference between North and South, but should be treated with caution as the number of actual cases is relatively small.

We do not yet have sufficient numbers to estimate Northern Ireland, and Wales and Scotland have not yet joined the COVID testing scheme, but we hope to extend testing to those nations shortly.

The daily new cases estimate does not account for those in the population who are asymptomatic (i.e. show no symptoms but can still spread the virus), as we cannot detect these cases by those reporting their health using the app. These figures also exclude care homes as there is not enough data from the app to estimate this population at this point.

Daily new cases of COVID-19 in England between 2-15 May

Notes

[*] This analysis requires swab testing, which was kindly provided by the English Department of Health and Social Care. The results do not currently include Wales & Scotland as they are not currently participating in this study, but ZOE hopes to extend testing to those nations shortly.  Testing is happening in Northern Ireland, but the number of participants is too few to generate an accurate estimate. These figures exclude care homes as there is not enough data from the app to estimate this population.

The regional breakdown of daily new cases per 1M people is:

  • England overall: 156-199
  • South East: 101-176
  • London: 88-179
  • Midlands: 169-310
  • East of England: 109-224
  • South West: 71-172
  • North East and Yorkshire: 157-304
  • North West: 217-412

The regional breakdown of total daily new cases is:

  • England overall: 8700-11100
  • South East: 900-1600
  • London: 800-1600
  • Midlands: 1800-3300
  • East of England: 700-1500
  • South West: 400-1000
  • North East and Yorkshire: 1300-2600
  • North West: 1500-2900