One in five people in England may have had coronavirus, a new model suggests, equivalent to 12.4 million people, rising to almost one in two in some areas.
It means that in England the actual number of people infected to date may be five times higher than the total number of known cases according to the government board.
However, in some parts of the country, the disparity may be even greater, with parts of London and the South estimated to have had up to eight times more cases than have been detected to date.
The analysis, for Edge Health, reveals that the total number of actual coronavirus infections in England could reach 12.4 million, equivalent to 22% of people in England, as of January 3.
Cases detected through the government’s testing and tracing program stood at 2.4 million on the same date in England.
The model estimates the number of cases in an area by comparing the number of deaths in the area with an estimated death rate from infection. Assume there is a three-week lag between the recorded cases and any associated deaths.
The results suggest that more than 10% of residents in 138 of England’s 149 top-tier local authorities have been estimated to have contracted the disease.
In some areas, the cases are even higher. The model suggests that two out of five people have been infected in six local authorities in London and the South East: Barking and Dagenham, Newham, Thurrock, Redbridge, Havering and Tower Hamlets.
The London boroughs of Barking and Dagenham and Newham are estimated to have had more than 100,000 coronavirus infections each, about 54.2% and 49% of their populations, respectively.
Official figures from England Public Health show that just under 14,700 cases had been recorded in Barking and Dagenham and just under 21,700 in Newham as of January 3.
According to the model, four local authorities in the northwest, which were most affected at the start of the second wave of the pandemic, were among the 10 most affected local authorities: Liverpool with 38.8% infected, Manchester with 38, 6%, Rochdale with 38%. and Salford at 37.8%.
The estimates are consistent with the accepted knowledge that the actual number of infections is likely to be much higher than the number of recorded cases due to asymptomatic cases and tests that do not detect all cases. This is especially true at the beginning of the pandemic, when the UK’s testing regime was much poorer.
Official government data on cases recorded to date show that Merthyr Tydfil, Blackburn with Darwen and Blaenau Gwent have the highest rates of recorded cases. However, the new estimates suggest that the published case numbers are much lower than the “true” level of infection.
The daily testing capacity remained below 40,000 during the first half of April, while it now exceeds 500,000.
The model suggests that Newham, Reading and Barking, and Dagenham have each seen nearly eight times more infections than the official recorded figures.
The estimated cases are more than five times the official count in 77 areas of England, just over half of the 149 high-level local authorities analyzed.
George Batchelor, Co-Founder and Director of Edge Health, which produced the modeled data, said: “The reported evidence is just a fraction of the picture of total infections, showing how severely London and the North West have been affected during the pandemic. It is incredible that the level of understanding of where and how infections occur is not higher at this stage, as it would allow control measures to be more specific.
“Even with imminent vaccinations, developing this knowledge is critical so that future variants of the virus can be effectively controlled and managed.”
The areas with the lowest estimated total infection rates are all in the South West: Devon (5.9%), Dorset (5.8%) and Cornwall (4.8%).
Edge Health Estimated total cases by looking at each local authority’s Covid-related deaths (as published by the ONS) and their estimated infection mortality rate (IFR).
The IFR is calculated by looking at the age profile of a local authority and applying the age-specific infection mortality rates of Cambridge University Research. These infection mortality rates are slightly lower for the second wave.
Once these two metrics are known, researchers can estimate the number of cases on any given day by scaling the number of deaths in 18 days (used here as a standardized time period between recorded infection and death) by estimated mortality. by infection of an area. proportion. The number of cases modeled is extrapolated to the present by assessing how test positivity rates have changed over the past three months.
While the model takes into account the cases, deaths, and age structure of an area, it does not consider other factors such as deprivation.
Karl Friston, Professor of Imaging Neuroscience at University College London and Independent SAGE panelist with special responsibility for modeling, said: “Generally speaking, the number of new cases per day is between four and eight times the number of cases. confirmed. “
Own UCL modeling had a strong correlation with Edge’s results, leading Friston to say there was a “nice consilience” with the two models.
George is Digismak’s reported cum editor with 13 years of experience in Journalism