Coronavirus infections increase exponentially in England – REACT study | Imperial News
The number of people infected with the coronavirus is increasing rapidly in England, doubling every 11 days.
New data from the REACT study, based on nearly 110,000 home swab tests performed between May 20 and June 7, estimates that 0.15% of people have the virus, or about 1 in 670. This is a 50% increase from the previous study results. , while 0.1% or 1 in 1,000 had the virus as of May 3.
“These data coincide with the fact that the Delta variant is becoming dominant and show the importance of continuing to monitor infection rates and variants.” Prof. Paul Elliott School of Public Health
Led by Imperial College London, the scientists estimate the reproduction number (R) to be 1.44, meaning that 10 infected people would pass the virus to 14 others on average, causing the epidemic to grow rapidly .
Most infections occur in children and young adults, but they also increase in older people, increasing at a similar rate in those over 50 and under 50.
The study found that the link between infections, hospitalizations and deaths had weakened since February, suggesting that infections led to fewer hospitalizations and deaths due to the vaccination schedule. But since the end of April, the trend has been reversed for hospitalizations.
Professor Paul Elliott, director of the REACT program at Imperial’s School of Public Health, said: “We found strong evidence of exponential growth in infection from late May to early June in the REACT-1 study. , with a doubling time of 11 days on average. for England. These data coincide with the fact that the Delta variant is becoming dominant and show the importance of continuing to monitor infection rates and variants of concern in the community. “
These conclusions of the program undergoing real-time evaluation of community transmission (REACT-1), led by Imperial and carried out in partnership with Ipsos MORI, are available here in a pre-printed report and will be subject to peer review.
For this latest round of the ongoing REACT study, 108,911 people were buffered at home and their samples were analyzed by PCR. 135 of them were positive, of which the vast majority (around 90%) were the Delta variant at the end of the study cycle. This is consistent with data from Public Health England (PHE) indicating that the variant accounts for 90% of infections.
“If this growth continues, it will lead to an increase in infections among older and more vulnerable people, and lead to more hospitalizations and deaths. “ Professor Steven Riley School of Public Health
In the study’s previous round of testing, infection patterns were quite similar across the country, but the latest data showed substantial regional variation. The highest prevalence was found in the Northwest at 0.26%, down from 0.11% in the previous cycle, while the Southwest had the lowest at 0.05%, down slightly from at 0.07%.
By age, 5-12 year olds and 18-24 year olds had the highest prevalence at 0.35% and 0.36%. Although the prevalence in people under 50 is 2.5 times higher than in people 50 and over (0.20% vs. 0.08%), infections appear to increase at a similar rate in both groups.
The study also followed the relationship between infections, hospitalizations and deaths in different age groups. Since February, the link between infections, hospitalizations and deaths has weakened among people aged 65 and over, while there has been a recent reversal of these trends for those under 65, leading to a recent reversal of these trends. probably reflects the decline in vaccination rates in this group.
Professor Steven Riley, Professor of Infectious Disease Dynamics at Imperial, said: “Even though we are seeing the highest prevalence of infection among young people who are less susceptible to COVID-19, if this growth continues, it will lead to an increase in infections in older and more vulnerable people. people because vaccines are not 100% effective and not everyone has been fully immunized. This would lead to more hospitalizations and deaths, and risk straining the NHS, which is why it is essential that people accept their vaccine offer and continue to play by the rules. “
Monitoring the COVID-19 epidemic
The REACT-1 study follows current coronavirus infections in the community by testing more than 100,000 randomly selected people each month over a period of approximately two weeks. The study recruits new people every month to ensure that the sample represents the population at large and provides a high-resolution snapshot of the situation over a period of time.
This is different from the ONS COVID-19 infection survey which runs continuously and samples the same people over time to understand transmission in households. Since the studies use different methods, this means that they sometimes report different numbers.
“We all need to keep our cool a little longer as the rollout of our vaccine continues.” Matt hancock Health and Social Affairs Secretary
Health and Social Affairs Secretary Matt Hancock said: “These findings highlight the difficult context in which we made the difficult decision to delay step 4 of the roadmap out of lockdown.
“Cases are increasing now, but thanks to our incredible vaccination program and improved response plan, including advanced testing, we have the tools to stop the spread of this virus.
“We all need to keep our cool a little longer as our vaccine rollout continues and I urge everyone to continue to observe hands, faces, space and the fresh air, and to make sure that you receive both doses of the vaccine for the best possible protection. ”
Kelly Beaver, Managing Director of Public Affairs at Ipsos MORI, said: “The increase in the number of cases noted by the REACT-1 study is of concern and is factored into government decision making in real time.
“While the increase is small, increasing the R number to more than one highlights the potential for that number to increase rapidly, an important reminder to get vaccinated when you can. I want to thank them nearly 2 million members of the public who ‘I have participated in the REACT-1 study since its launch a year ago to help provide this crucial piece of evidence to government.