Imperial College London

Fall in coronavirus infections has slowed in England – REACT study

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Coronavirus infections continue to fall in England but no longer at the sharp rate seen in early February, according to new data from REACT.

The study – the largest programme of home coronavirus testing – tested over 163,500 people across the country between the 4th and 23rd February, finding that around 1 in 204 people are currently infected, or 0.49% of the population. 

This is a fall of more than two-thirds since January when 1 in 64 was infected (1.57%), and a similar prevalence to the study’s recent interim findings when about 1 in 200 people had the virus, or 0.51% as of 13th February, meaning the rate of decline has slowed. 

"These new findings reinforce the need for everyone to continue to stick to the rules and help keep infections down." Prof Paul Elliott School of Public Health, Imperial

The researchers from Imperial College London found that the reproduction number (R) was 0.86 at the national level, which means that the epidemic is still shrinking as each infected person passes the virus on to fewer than one other on average. However, there are variations across the country and the study has picked up a suggestion that infections are rising again in London, the South East and the Midlands. 

Professor Paul Elliott, director of the REACT programme from Imperial’s School of Public Health, said: “The fall in infections our study has observed since January demonstrates that national public health measures are working. But these new findings showing that some areas are experiencing apparent growth reinforce the need for everyone to continue to stick to the rules and help keep infections down. At this critical time, with lockdown soon to be eased, we need to make sure that our behaviours don’t risk a rise in infections which could prolong restrictions, which we all want to avoid.”

These findings from the ongoing REal-time Assessment of Community Transmission (REACT 1) programme, led by Imperial and carried out in partnership with Ipsos MORI, are available in a pre-print report and will be submitted for peer-review.

Trends in coronavirus infections

Out of 78,047 swab tests taken at home for the second half of this study round, from 13th to 23rd February, 301 were positive giving an infection prevalence of 0.47%, or 47 people per 10,000 infected. This compares with 51 per 10,000 during the first half of the study round, from 4th to 12th February.

Over the entire study round, the prevalence was 0.49% and the rate of new infections was found to be halving every 31 days.

Compared to the study’s findings from January, infections fell by at least half across all age groups, with the lowest prevalence currently found in people aged 65 and above (0.21%), and the highest in children aged 13-17 (0.71%).

"Given all the sacrifices we have made in the last year, now is not the time to risk returning to even higher levels of infections." Prof Steven Riley Professor of Infectious Disease Dynamics, Imperial

Although prevalence also fell substantially in all regions since January, across this testing round there was variation in patterns of growth and decline across the country. In the North East, North West, East of England and South West infections fell throughout the study round, but the rate of infections remained steady in Yorkshire and the Humber. Conversely in London, the South East, East Midlands and West Midlands there has been an apparent rise in infections. 

Patterns were also uneven across London, with north and east London experiencing an apparent decline and west and south London seeing an apparent increase. 

Professor Steven Riley, Professor of Infectious Disease Dynamics at Imperial, said: “As the decline in the rate of new infections slows down, we should aim to avoid returning to growth in the number of infections. In the next few weeks and months, many millions more in the UK will be protected by vaccine. Given all the sacrifices we have made in the last year, now is not the time to risk returning to even higher levels of infections.”

Identifying at risk groups

Ethnic minorities had a higher risk of being infected with Asian people twice as likely as White people to test positive (0.91% vs 0.45%), the highest prevalence being found in Pakistani individuals at 2.1%. Black people also had a higher risk at 0.83%. 

"There is some cause for concern that our hard-won progress may be slowing down." Matt Hancock Health Secretary

Healthcare workers and care home workers had 40% to 50% higher risk of infection compared with other workers. Participants who worked in public transport had double the risk of testing positive compared with those who did not, and between a 20% to 40% higher risk of infection was also seen in those working in education, school, nursery or childcare compared with participants not working in those settings. People who were required to work from home had a 30% to 40% lower risk of infection than those who were not.

Health and Social Care Secretary Matt Hancock said: ““It is encouraging to see continued evidence of cases falling overall, and I want to thank everyone for sticking to the rules and supporting each other through this pandemic.

“There is some cause for concern that our hard-won progress may be slowing down, and even reversing in some regions so it is important we remain vigilant - this is on all of us.

“We have set out a cautious, but irreversible approach to easing restrictions but until we reach each milestone, we must all remember the virus is still here, and still dangerous. Please continue to stay at home - practice hands, face, space – and get your jab when you receive your invite so we can bring down infections further.”

Understanding levels of infection in the community

The REACT 1 study is tracking current coronavirus infections in the community by testing more than 150,000 randomly-selected people each month over a two-week period. The study recruits new people each month to help ensure the sample represents the wider population and offers a high-resolution snapshot of the situation across a particular time period.

This is different from the ONS COVID-19 Infection Survey which runs continuously and samples the same people over time to understand household transmission. Because the studies use different methods, this means that sometimes they report different figures.

"The potential shallowing of the decline reinforces the message that all of us must continue to stick to the measures which are in place for as long as is necessary." Kelly Beaver Managing Director - Public Affairs, Ipsos MORI

People who volunteer for REACT take throat and nose swabs at home, which are then analysed in a laboratory by a technique called RT-PCR. These findings are helping guide public health measures so that the Government can better respond to the pandemic as the situation evolves.

Kelly Beaver, Managing Director- Public Affairs at Ipsos MORI said: “The 50% prevalence reduction across all age groups is very welcome and shows that we are making progress in fighting this pandemic. The potential shallowing of the decline though reinforces the message that all of us must continue to stick to the measures which are in place for as long as is necessary so that we can stay on the path set out in the Prime Minister’s roadmap.

"Over the coming weeks and months as we hope to progress through the roadmap milestones, the REACT study will continue to be a critical data source aiding government understanding of the virus. Thanks to those participating in the study for their important contribution.”


Access the study's findings here.

Reporter

Justine Alford

Justine Alford
Institute of Global Health Innovation

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Email: press.office@imperial.ac.uk
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