Coronavirus cases in England doubling every eight days, study shows
Cases of coronavirus in England are doubling every seven to eight days, research has revealed in the latest figures to show a resurgence of Covid-19.
The study, known as React-1, is a population surveillance study that began in May and uses swabs from about 120,000 to 160,000 randomly selected people in England across 315 local authority areas each month to track the spread of coronavirus using PCR analysis – the “have you got it now” test.
“The prevalence of the virus in the population is increasing. We found evidence that it has been accelerating at the end of August and beginning of September,” said Steven Riley, professor of infectious disease dynamics at Imperial College London and a co-author of the work.
The findings came as, elsewhere, the latest R figure for the UK was reported to be between 1.0 and 1.2, with the number of new infections somewhere between shrinking by 1% and growing by 3% every day.
Previous rounds of the study revealed a falling prevalence of Covid-19, even as lockdown restrictions were eased: according to data for the period 19 June to 8 July, the prevalence of Covid in the general population was low, and halving every eight to nine days.
However, the results from the fourth round of the survey suggest that is no longer the case. While the latest findings from the React study have yet to be peer-reviewed, researchers say out of more than 150,000 swabs collected between 22 August and 7 September, 136 tested positive for coronavirus, suggesting 13 people out of every 10,000 in the general population had Covid-19.
Although the prevalence is still far lower than it was in March and April, the team note it is higher than measured by the survey between 19 June and 8 July and between 24 July and 11 August.
The results reveal cases are rising in almost all regions, but it is more pronounced in some areas than others, with Yorkshire and the Humber, the north-west and north-east showing the highest prevalence of Covid-19.
“It is happening everywhere but it is happening more in some places than others,” said Prof Paul Elliott, the director of the React programme and chair in epidemiology and public health medicine at Imperial College London.
Riley agreed. “There is a difference in the starting level and there is a difference in the speed [in different areas],” he said. “But I think the overall trend of moving into growth does seem to be affecting a really large proportion of England.”
The team add the survey data between 22 August and 7 September suggests prevalence is doubling every 7.7 days, with the R value for England estimated to be 1.7. At the start of lockdown prevalence was doubling about every three to four days. In addition, the team say the cases are no longer primarily found in clusters in care home and hospital settings, but are spreading more widely in the community.
Among other findings, the team found that almost two-thirds of those who tested positive for Covid-19 had no symptoms either at the time the swab was taken, or in the seven days before. But the team note they did not look at how infectious individuals were.
While the data shows the rates are at present highest among 18-24-year
olds, with a marked increase from the previous round, the team say rises have been recorded across many age groups, including children aged five to 12.
“All the way up to 65 years old, amongst adults the prevalence has been increasing, so it is not just happening in the younger people,” said Elliott, adding over-65s might be continuing to shield.
The latest results reveal prevalence was also higher among minority ethic groups compared with the white population.
The health and social care secretary, Matt Hancock, warned the pandemic was not over. He said: “It’s so important that everyone abides by the law and socialises in groups up to six. Make space between you and those outside your household, get a test and selfisolate if you develop symptoms and wash your hands regularly. It is vital you engage with the NHS test and trace service if contacted to provide details of your close contacts and self-isolate if you are asked to do so.”
Dr Zania Stamataki, a viral immunologist at the University of Birmingham, agreed. “This detailed study clearly shows how valuable it is for us to continue to monitor infections using testing, and how contact tracing can actually help identify other infected people for isolation even in the absence of symptoms,” she said.
“There is a real risk that the surge in cases, even amongst the young, will soon translate to increased hospitalisations of the vulnerable.”