Imperial College London

DrChristinaAtchison

Faculty of MedicineSchool of Public Health

Principal Clinical Academic Fellow
 
 
 
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christina.atchison11

 
 
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Reynolds BuildingCharing Cross Campus

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Summary

 

Publications

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60 results found

Bowman L, Kwok KO, Redd R, Yi Y, Ward H, Wei WI, Atchison C, Wong SY-Set al., 2021, Comparing Public Perceptions and Preventive Behaviors During the Early Phase of the COVID-19 Pandemic in Hong Kong and the United Kingdom: Cross-sectional Survey Study, JOURNAL OF MEDICAL INTERNET RESEARCH, Vol: 23, ISSN: 1438-8871

Journal article

Riley S, Wang H, Eales O, Haw D, Walters C, Ainslie K, Atchison C, Fronterre C, Diggle P, Ashby D, Donnelly C, Cooke G, Barclay W, Ward H, Darzi A, Elliott Pet al., 2021, REACT-1 round 9 final report: Continued but slowing decline of prevalence of SARS-CoV-2 during national lockdown in England in February 2021

BackgroundEngland will start to exit its third national lockdown in response to the COVID-19 pandemicon 8th March 2021, with safe effective vaccines being rolled out rapidly against abackground of emerging transmissible and immunologically novel variants of SARS-CoV-2.A subsequent increase in community prevalence of infection could delay further relaxation oflockdown if vaccine uptake and efficacy are not sufficiently high to prevent increasedpressure on healthcare services.MethodsThe PCR self-swab arm of the REal-time Assessment of Community Transmission Study(REACT-1) estimates community prevalence of SARS-CoV-2 infection in England based onrandom cross-sections of the population ages five and over. Here, we present results fromthe complete round 9 of REACT-1 comprising round 9a in which swabs were collected from4th to 12th February 2021 and round 9b from 13th to 23rd February 2021. We also comparethe results of REACT-1 round 9 to round 8, in which swabs were collected mainly from 6thJanuary to 22nd January 2021.ResultsOut of 165,456 results for round 9 overall, 689 were positive. Overall weighted prevalence ofinfection in the community in England was 0.49% (0.44%, 0.55%), representing a fall of overone third from round 8. However the rate of decline of the epidemic has slowed from 15 (13,17) days, estimated for the period from the end of round 8 to the start of round 9, to 31 daysestimated using data from round 9 alone (lower confidence limit 17 days). When comparinground 9a to 9b there were apparent falls in four regions, no apparent change in one regionand apparent rises in four regions, including London where there was a suggestion ofsub-regional heterogeneity in growth and decline. Smoothed prevalence maps suggest largecontiguous areas of growth and decline that do not align with administrative regions.Prevalence fell by 50% or more across all age groups in round 9 compared to round 8, withprevalence (round 9) ranging from 0.21% in those aged 65 and over to 0

Working paper

Ward H, Cooke G, Whitaker M, Redd R, Eales O, Brown J, Collet K, Cooper E, Daunt A, Jones K, Moshe M, Willicombe M, Day S, Atchison C, Darzi A, Donnelly C, Riley S, Ashby D, Barclay W, Elliott Pet al., 2021, REACT-2 Round 5: increasing prevalence of SARS-CoV-2 antibodies demonstrate impact of the second wave and of vaccine roll-out in England

BackgroundEngland has experienced high rates of SARS-CoV-2 infection during the COVID-19 pandemic, affecting in particular minority ethnic groups and more deprived communities. A vaccination programme began in England in December 2020, with priority given to administering thefirst dose to the largest number of older individuals, healthcare and care home workers.MethodsA cross-sectional community survey in England undertaken between 26 January and 8 February 2021 as the fifth round of the REal-time Assessment of Community Transmission-2 (REACT-2) programme. Participants completed questionnaires, including demographic details and clinical and COVID-19 vaccination histories, and self-administered a lateral flowimmunoassay (LFIA) test to detect IgG against SARS-CoV-2 spike protein. There were sufficient numbers of participants to analyse antibody positivity after 21 days from vaccination with the PfizerBioNTech but not the AstraZeneca/Oxford vaccine which was introduced slightly later.ResultsThe survey comprised 172,099 people, with valid IgG antibody results from 155,172. The overall prevalence of antibodies (weighted to be representative of the population of England and adjusted for test sensitivity and specificity) in England was 13.9% (95% CI 13.7, 14.1) overall, 37.9% (37.2, 38.7) in vaccinated and 9.8% (9.6, 10.0) in unvaccinated people.The prevalence of antibodies (weighted) in unvaccinated people was highest in London at 16.9% (16.3, 17.5), and higher in people of Black (22.4%, 20.8, 24.1) and Asian (20.0%, 19.0, 21.0) ethnicity compared to white (8.5%, 8.3, 8.7) people. The uptake of vaccination by age was highest in those aged 80 years or older (93.5%). Vaccine confidence was high with 92.0% (91.9, 92.1) of people saying that they had accepted or intended to accept the offer.Vaccine confidence varied by age and ethnicity, with lower confidence in young people and those of Black ethnicity. Particular concerns were identified around pregnancy, fertility and alle

Working paper

Riley S, Walters C, Wang H, Eales O, Haw D, Ainslie K, Atchison C, Fronterre C, Diggle P, Ashby D, Donnelly C, Cooke G, Barclay W, Ward H, Darzi A, Elliott Pet al., 2021, REACT-1 round 9 interim report: downward trend of SARS-CoV-2 in England in February 2021 but still at high prevalence

Background and Methods: England entered its third national lockdown of the COVID-19pandemic on 6th January 2021 with the aim of reducing the daily number of deaths andpressure on healthcare services. The real-time assessment of community transmission study(REACT-1) obtains throat and nose swabs from randomly selected people in England inorder to describe patterns of SARS-CoV-2 prevalence. Here, we report data from round 9aof REACT-1 for swabs collected between 4th and 13th February 2021.Results: Out of 85,473 tested-swabs, 378 were positive. Overall weighted prevalence ofinfection in the community in England was 0.51%, a fall of more than two thirds since our lastreport (round 8) in January 2021 when 1.57% of people tested positive. We estimate ahalving time of 14.6 days and a reproduction number R of 0.72, based on the difference inprevalence between the end of round 8 and the beginning of round 9. Although prevalencefell in all nine regions of England over the same period, there was greater uncertainty in thetrend for North West, North East, and Yorkshire and The Humber. Prevalence fellsubstantially across all age groups with highest prevalence among 18- to 24-year olds at0.89% (0.47%, 1.67%) and those aged 5 to12 years at 0.86% (0.60%, 1.24%). Largehousehold size, living in a deprived neighbourhood, and Asian ethnicity were all associatedwith increased prevalence. Healthcare and care home workers were more likely to testpositive compared to other workers.Conclusions: There is a strong decline in prevalence of SARS-CoV-2 in England among thegeneral population five to six weeks into lockdown, but prevalence remains high: at levelssimilar to those observed in late September 2020. Also, the number of COVID-19 cases inhospitals is higher than at the peak of the first wave in April 2020. The effects of easing ofsocial distancing when we transition out of lockdown need to be closely monitored to avoid aresurgence in infections and renewed pressure on health services.

Working paper

Ward H, Atchison C, Whitaker M, Ainslie KEC, Elliott J, Okell L, Redd R, Ashby D, Donnelly C, Barclay W, Darzi A, Cooke G, Riley S, Elliott Pet al., 2021, SARS-CoV-2 antibody prevalence in England following the first peak of the pandemic., Nature Communications, Vol: 12, Pages: 1-8, ISSN: 2041-1723

England has experienced a large outbreak of SARS-CoV-2, disproportionately affecting people from disadvantaged and ethnic minority communities. It is unclear how much of this excess is due to differences in exposure associated with structural inequalities. Here we report from the REal-time Assessment of Community Transmission-2 (REACT-2) national study of over 100,000 people. After adjusting for test characteristics and re-weighting to the population, overall antibody prevalence is 6.0% (95% CI: 5.8-6.1). An estimated 3.4 million people had developed antibodies to SARS-CoV-2 by mid-July 2020. Prevalence is two- to three-fold higher among health and care workers compared with non-essential workers, and in people of Black or South Asian than white ethnicity, while age- and sex-specific infection fatality ratios are similar across ethnicities. Our results indicate that higher hospitalisation and mortality from COVID-19 in minority ethnic groups may reflect higher rates of infection rather than differential experience of disease or care.

Journal article

Riley S, Eales O, Walters C, Wang H, Ainslie K, Atchison C, Fronterre C, Diggle P, Ashby D, Donnelly C, Cooke G, Barclay W, Darzi A, Elliott P, Ward Het al., 2021, REACT-1 round 8 final report: high average prevalence with regional heterogeneity of trends in SARS-CoV-2 infection in the community in England during January 2021

In early January 2021, England entered its third national lockdown of the COVID-19 pandemic to reduce numbers of deaths and pressure on healthcare services, while rapidly rolling out vaccination to healthcare workers and those most at risk of severe disease and death. REACT-1 is a survey of SARS-CoV-2 prevalence in the community in England, based on repeated cross-sectional samples of the population. Between 6th and 22nd January 2021, out of 167,642 results, 2,282 were positive giving a weighted national prevalence of infection of 1.57% (95% CI, 1.49%, 1.66%). The R number nationally over this period was estimated at 0.98 (0.92, 1.04). Prevalence remained high throughout, but with suggestion of a decline at the end of the study period. The average national trend masked regional heterogeneity, with robustly decreasing prevalence in one region (South West) and increasing prevalence in another (East Midlands). Overall prevalence at regional level was highest in London at 2.83% (2.53%, 3.16%). Although prevalence nationally was highest in the low-risk 18 to 24 year old group at 2.44% (1.96%, 3.03%), it was also high in those over 65 years who are most at risk, at 0.93% (0.82%, 1.05%). Large household size, living in a deprived neighbourhood, and Black and Asian ethnicity were all associated with higher levels of infections compared to smaller households, less deprived neighbourhoods and other ethnicities. Healthcare and care home workers, and other key workers, were more likely to test positive compared to other workers. If sustained lower prevalence is not achieved rapidly in England, pressure on healthcare services and numbers of COVID-19 deaths will remain unacceptably high.

Working paper

Riley S, Wang H, Eales O, Walters C, Ainslie K, Atchison C, Fronterre C, Diggle P, Ashby D, Donnelly C, Cooke G, Barclay W, Ward H, Darzi A, Elliott Pet al., 2021, REACT-1 round 8 interim report: SARS-CoV-2 prevalence during the initial stages of the third national lockdown in England, Publisher: Imperial College London

BackgroundHigh prevalence of SARS-CoV-2 virus in many northern hemisphere populations is causingextreme pressure on healthcare services and leading to high numbers of fatalities. Eventhough safe and effective vaccines are being deployed in many populations, the majority ofthose most at-risk of severe COVID-19 will not be protected until late spring, even incountries already at a more advanced stage of vaccine deployment.MethodsThe REal-time Assessment of Community Transmission study-1 (REACT-1) obtains throatand nose swabs from between 120,000 and 180,000 people in the community in England atapproximately monthly intervals. Round 8a of REACT-1 mainly covers a period from 6thJanuary 2021 to 15th January 2021. Swabs are tested for SARS-CoV-2 virus and patterns ofswab-positivity are described over time, space and with respect to individual characteristics.We compare swab-positivity prevalence from REACT-1 with mobility data based on the GPSlocations of individuals using the Facebook mobile phone app. We also compare resultsfrom round 8a with those from round 7 in which swabs were collected from 13th Novemberto 24th November (round 7a) and 25th November to 3rd December 2020 (round 7b).ResultsIn round 8a, we found 1,962 positives from 142,909 swabs giving a weighted prevalence of1.58% (95% CI, 1.49%, 1.68%). Using a constant growth model, we found no strongevidence for either growth or decay averaged across the period; rather, based on data froma limited number of days, prevalence may have started to rise at the end of round 8a.Facebook mobility data showed a marked decrease in activity at the end of December 2020,followed by a rise at the start of the working year in January 2021. Between round 7b andround 8a, prevalence increased in all adult age groups, more than doubling to 0.94%(0.83%, 1.07%) in those aged 65 and over. Large household size, living in a deprivedneighbourhood, and Black and Asian ethnicity were all associated with increasedprevalence. Both healthcare

Working paper

Atchison C, Bowman LR, Vrinten C, Redd R, Pristerà P, Eaton J, Ward Het al., 2021, Early perceptions and behavioural responses during the COVID-19 pandemic: a cross-sectional survey of UK adults., BMJ Open, Vol: 11, Pages: 1-12, ISSN: 2044-6055

OBJECTIVE: To examine risk perceptions and behavioural responses of the UK adult population during the early phase of the COVID-19 epidemic in the UK. DESIGN: A cross-sectional survey. SETTING: Conducted with a nationally representative sample of UK adults within 48 hours of the UK Government advising the public to stop non-essential contact with others and all unnecessary travel. PARTICIPANTS: 2108 adults living in the UK aged 18 years and over. Response rate was 84.3% (2108/2500). Data collected between 17 March and 18 March 2020. MAIN OUTCOME MEASURES: Descriptive statistics for all survey questions, including number of respondents and weighted percentages. Robust Poisson regression used to identify sociodemographic variation in: (1) adoption of social distancing measures, (2) ability to work from home, and (3) ability and (4) willingness to self-isolate. RESULTS: Overall, 1992 (94.2%) respondents reported at least one preventive measure: 85.8% washed their hands with soap more frequently; 56.5% avoided crowded areas and 54.5% avoided social events. Adoption of social distancing measures was higher in those aged over 70 years compared with younger adults aged 18-34 years (adjusted relative risk/aRR: 1.2; 95% CI: 1.1 to 1.5). Those with lowest household income were three times less likely to be able to work from home (aRR: 0.33; 95% CI: 0.24 to 0.45) and less likely to be able to self-isolate (aRR: 0.92; 95% CI: 0.88 to 0.96). Ability to self-isolate was also lower in black and minority ethnic groups (aRR: 0.89; 95% CI: 0.79 to 1.0). Willingness to self-isolate was high across all respondents. CONCLUSIONS: Ability to adopt and comply with certain non-pharmaceutical interventions (NPIs) is lower in the most economically disadvantaged in society. Governments must implement appropriate social and economic policies to mitigate this. By incorporating these differences in NPIs among socioeconomic subpopulations into mathematical models of COV

Journal article

Riley S, Walters C, Wang H, Eales O, Ainslie K, Atchison C, Fronterre C, Diggle PJ, Ashby D, Donnelly C, Cooke G, Barclay W, Ward H, Darzi A, Elliott Pet al., 2020, REACT-1 round 7 updated report: regional heterogeneity in changes in prevalence of SARS-CoV-2 infection during the second national COVID-19 lockdown in England, REACT-1 round 7 updated report: regional heterogeneity in changes in prevalence of SARS-CoV-2 infection during the second national COVID-19 lockdown in England, London, Publisher: Imperial College London

BackgroundEngland exited a four-week second national lockdown on 2nd December 2020 initiated in response to the COVID-19 pandemic. Prior results showed that prevalence dropped during the first half of lockdown, with greater reductions in higher-prevalence northern regions.MethodsREACT-1 is a series of community surveys of SARS-CoV-2 RT-PCR swab-positivity in England, designed to monitor the spread of the epidemic and thus increase situational awareness. Round 7 of REACT-1 commenced swab-collection on 13th November 2020. A prior interim report included data from 13th to 24th November 2020 for 105,122 participants. Here, we report data for the entire round with swab results obtained up to 3rd December 2020.ResultsBetween 13th November and 3rd December (round 7) there were 1,299 positive swabs out of 168,181 giving a weighted prevalence of 0.94% (95% CI 0.87%, 1.01%) or 94 per 10,000 people infected in the community in England. This compares with a prevalence of 1.30% (1.21%, 1.39%) from 16th October to 2nd November 2020 (round 6), a decline of 28%. Prevalence during the latter half of round 7 was 0.91% (95% CI, 0.81%, 1.03%) compared with 0.96% (0.87%, 1.05%) in the first half. The national R number in round 7 was estimated at 0.96 (0.88, 1.03) with a decline in prevalence observed during the first half of this period no longer apparent during the second half at the end of lockdown. During round 7 there was a marked fall in prevalence in West Midlands, a levelling off in some regions and a rise in London. R numbers at regional level ranged from 0.60 (0.41, 0.80) in West Midlands up to 1.27 (1.04, 1.54) in London, where prevalence was highest in the east and south-east of the city. Nationally, between 13th November and 3rd December, the highest prevalence was in school-aged children especially at ages 13-17 years at 2.04% (1.69%, 2.46%), or approximately 1 in 50.ConclusionBetween the previous round and round 7 (during lockdown), there was a fall in prevalence of SARS-C

Report

Castro-Sánchez E, CM A C A D P W L, ME C, Garcia D M C C, JM M D R K D, HS G, JA O M Wet al., 2020, Evaluation of a personal protective equipment (PPE) support programme ('PPE Helpers') for staff during the COVID-19 pandemic in London, Journal of Hospital Infection, ISSN: 0195-6701

BackgroundThe COVID-19 pandemic has presented one of the biggest challenges to healthcare providers worldwide. The appropriate use of Personal Protective Equipment (PPE) has been essential to ensuring staff and patient safety. To counteract sub-optimal PPE practice, a PPE helper programme was developed at a large London hospital group. Based on a behaviour change model of Capability, Opportunity and Motivation (COM-B), the programme provided PPE support, advice and education to ward staff.AimEvaluation of the PPE Helper Programme.MethodsClinical and non-clinical ward staff completed a questionnaire informed by the Theoretical Domains Framework and COM-B. The questionnaire was available in paper and electronic versions. Quantitative responses were analysed using descriptive and non-parametric statistics, free-text responses were analysed thematically.FindingsOver a six-week period, PPE helpers made 268 ward visits. Overall, 261 questionnaires were available for analysis. Across the Trust, 68% of respondents reported having had contact with a PPE helper. Staff who had encountered a PPE helper responded significantly more positively to a range of statements about using PPE than those who had not. Black and Minority Ethnic (BAME) staff were significantly more anxious in relation to the adequacy of PPE. Non-clinical and redeployed staff (e.g. domestic staff) were most positive about the impact of PPE helpers. Free-text comments showed that staff found the programme supportive and would have liked it earlier in the pandemic.ConclusionA PPE Helper programme is a feasible and beneficial intervention for providing support, advice and education to ward staff during infectious disease outbreaks.

Journal article

Riley S, Eales O, Walters C, Wang H, Ainslie K, Atchison C, Fronterre C, Diggle P, Ashby D, Donnelly C, Cooke G, Barclay W, Ward H, Darzi A, Elliott Pet al., 2020, REACT-1 round 7 interim report: fall in prevalence of swab-positivity in England during national lockdown, Publisher: Cold Spring Harbor Laboratory

Background The second wave of the 2020 COVID-19 pandemic in England has been characterized by high growth and prevalence in the North with lower prevalence in the South. High prevalence was first observed at younger adult ages before spreading out to school-aged children and older adults. Local tiered interventions were in place up to 5th November 2020 at which time a second national lockdown was implemented.Methods REACT-1 is a repeated cross-sectional survey of SARS-CoV-2 swab-positivity in random samples of the population of England. The current period of data collection (round 7) commenced on 13th November 2020 and we report interim results here for swabs collected up to and including 24th November 2020. Because there were two distinct periods of growth during the previous round 6, here we compare results from round 7 (mainly) with the second half of round 6, which obtained swabs between 26th October and 2nd November 2020. We report prevalence both unweighted and reweighted to be representative of the population of England. We describe trends in unweighted prevalence with daily growth rates, doubling times, reproduction numbers (R) and splines. We estimated odds ratios for swab-positivity using mutually-adjusted multivariable logistic regression models.Results We found 821 positives from 105,123 swabs giving an unweighted prevalence of 0.78% (95% CI, 0.73%, 0.84%) and a weighted prevalence of 0.96% (0.87%, 1.05%). The weighted prevalence estimate was ∼30% lower than that of 1.32% (1.20%, 1.45%) obtained in the second half of round 6. This decrease corresponds to a halving time of 37 (30, 47) days and an R number of 0.88 (0.86, 0.91). Using only data from the most recent period, we estimate an R number of 0.71 (0.54, 0.90). A spline fit to prevalence showed a rise shortly after the previous period of data collection followed by a fall coinciding with the start of lockdown. The national trends were driven mainly by reductions in higher-prevalence northern regi

Working paper

Riley S, Ainslie K, Eales O, Walters CE, Wang H, Atchinson C, Fronterre C, Diggle PJ, Ashby D, Donnelly C, Cooke G, Barclay W, Ward H, Darzi A, Elliott Pet al., 2020, REACT-1 round 6 updated report: high prevalence of SARS-CoV-2 swab positivity with reduced rate of growth in England at the start of November 2020

BackgroundEngland is now in the midst of its second wave of the COVID-19 pandemic. Multiple regions of the country are at high infection prevalence and all areas experienced rapid recent growth of the epidemic during October 2020.MethodsREACT-1 is a series of community surveys of SARS-CoV-2 RT-PCR swab-positivity in England designed to monitor the spread of the epidemic and thus increase situational awareness. Round 6 of REACT-1 commenced swab-collection on 16th October. A prior interim report included data from 16th to 25th October for 85,971 participants. Here, we report data for the entire round on 160,175 participants with swab results obtained up to 2nd November 2020.ResultsOverall weighted prevalence of infection in the community in England was 1.3% or 130 people per 10,000 infected, up from 60 people per 10,000 in the round 5 report (18th September to 5th October 2020), doubling every 24 days on average since the prior round. The corresponding R number was estimated to be 1.2. Prevalence of infection was highest in North West (2.4%, up from 1.2% ), followed by Yorkshire and The Humber (2.3% up from 0.84%), West Midlands (1.6% up from 0.60%), North East (1.5% up from 1.1%), East Midlands (1.3% up from 0.56%), London (0.97%, up from 0.54%), South West (0.80% up from 0.33%), South East (0.69% up from 0.29%), and East of England (0.69% up from 0.30%). Rapid growth in the South observed in the first half of round 6 was no longer apparent in the second half of round 6. We also observed a decline in prevalence in Yorkshire and The Humber during this period. Comparing the first and second halves of round 6, there was a suggestion of decline in weighted prevalence in participants aged 5 to 12 years and in those aged 25 to 44 years. While prevalence remained high, in the second half of round 6 there was suggestion of a slight fall then rise that was seen nationally and also separately in both the North and the South.ConclusionThe impact of the second national lockdown

Working paper

Riley S, Ainslie KEC, Eales O, Walters CE, Wang H, Atchinson CJ, Fronterre C, Diggle PJ, Ashby D, Donnelly CA, Cooke G, Barclay W, Ward H, Darzi A, Elliott Pet al., 2020, High prevalence of SARS-CoV-2 swab positivity and increasing R number in England during October 2020: REACT-1 round 6 interim report, Publisher: medRxiv

Background REACT-1 measures prevalence of SARS-CoV-2 infection in representative samples of the population in England using PCR testing from self-administered nose and throat swabs. Here we report interim results for round 6 of observations for swabs collected from the 16th to 25th October 2020 inclusive. Methods REACT-1 round 6 aims to collect data and swab results from 160,000 people aged 5 and above. Here we report results from the first 86,000 individuals. We estimate prevalence of PCR-confirmed SARS-CoV-2 infection, reproduction numbers (R) and temporal trends using exponential growth or decay models. Prevalence estimates are presented both unweighted and weighted to be representative of the population of England, accounting for response rate, region, deprivation and ethnicity. We compare these interim results with data from round 5, based on swabs collected from 18th September to 5th October 2020 inclusive. Results Overall prevalence of infection in the community in England was 1.28% or 128 people per 10,000, up from 60 per 10,000 in the previous round. Infections were doubling every 9.0 (6.1, 18) days with a national reproduction number (R) estimated at 1.56 (1.27, 1.88) compared to 1.16 (1.05, 1.27) in the previous round. Prevalence of infection was highest in Yorkshire and The Humber at 2.72% (2.12%, 3.50%), up from 0.84% (0.60%, 1.17%), and the North West at 2.27% (1.90%, 2.72%), up from 1.21% (1.01%, 1.46%), and lowest in South East at 0.55% (0.45%, 0.68%), up from 0.29% (0.23%, 0.37%). Clustering of cases was more prevalent in Lancashire, Manchester, Liverpool and West Yorkshire, West Midlands and East Midlands. Interim estimates of R were above 2 in the South East, East of England, London and South West, but with wide confidence intervals. Nationally, prevalence increased across all age groups with the greatest increase in those aged 55-64 at 1.20% (0.99%, 1.46%), up 3-fold from 0.37% (0.30%, 0.46%). In those aged over 65, prevalence was 0.81% (0.58%, 0

Working paper

Riley S, Ainslie KEC, Eales O, Walters CE, Wang H, Atchison C, Fronterre C, Diggle PJ, Ashby D, Donnelly CA, Cooke G, Barclay W, Ward H, Darzi A, Elliott Pet al., 2020, High and increasing prevalence of SARS-CoV-2 swab positivity in England during end September beginning October 2020: REACT-1 round 5 updated report, Publisher: Cold Spring Harbor Laboratory

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>REACT-1 is quantifying prevalence of SARS-CoV-2 infection among random samples of the population in England based on PCR testing of self-administered nose and throat swabs. Here we report results from the fifth round of observations for swabs collected from the 18th September to 5th October 2020. This report updates and should be read alongside our round 5 interim report.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Representative samples of the population aged 5 years and over in England with sample size ranging from 120,000 to 175,000 people at each round. Prevalence of PCR-confirmed SARS-CoV-2 infection, estimation of reproduction number (R) and time trends between and within rounds using exponential growth or decay models.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>175,000 volunteers tested across England between 18th September and 5th October. Findings show a national prevalence of 0.60% (95% confidence interval 0.55%, 0.71%) and doubling of the virus every 29 (17, 84) days in England corresponding to an estimated national R of 1.16 (1.05, 1.27). These results correspond to 1 in 170 people currently swab-positive for the virus and approximately 45,000 new infections each day. At regional level, the highest prevalence is in the North West, Yorkshire and The Humber and the North East with strongest regional growth in North West, Yorkshire and The Humber and West Midlands.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>Rapid growth has led to high prevalence of SARS-CoV-2 virus in England, with highest rates in the North of England. Prevalence has increased in all age groups, including those at highest risk. Improved compliance with existing policy and, as necessar

Working paper

Riley S, Ainslie KEC, Eales O, Walters CE, Wang H, Atchison C, Fronterre C, Diggle PJ, Ashby D, Donnelly CA, Cooke G, Barclay W, Ward H, Darzi A, Elliott Pet al., 2020, High prevalence of SARS-CoV-2 swab positivity in England during September 2020: interim report of round 5 of REACT-1 study, Publisher: Cold Spring Harbor Laboratory Press

Background REACT-1 is a community survey of PCR confirmed swab-positivity for SARS-CoV-2 among random samples of the population in England. This interim report includes data from the fifth round of data collection currently underway for swabs sampled from the 18th to 26th September 2020.Methods Repeated cross-sectional surveys of random samples of the population aged 5 years and over in England with sample size ranging from 120,000 to 160,000 people in each round of data collection. Collection of self-administered nose and throat swab for PCR and questionnaire data. Prevalence of swab-positivity by round and by demographic variables including age, sex, region, ethnicity. Estimation of reproduction number (R) between and within rounds, and time trends using exponential growth or decay model. Assessment of geographical clustering based on boundary-free spatial model.Results Over the 9 days for which data are available, we find 363 positives from 84,610 samples giving a weighted prevalence to date of 0.55% (0.47%, 0.64%) in round 5. This implies that 411,000 (351,000, 478,000) people in England are virus-positive under the assumption that the swab assay is 75% sensitive. Using data from the most recent two rounds, we estimate a doubling time of 10.6 (9.4, 12.0) days covering the period 20th August to 26th September, corresponding to a reproduction number R of 1.47 (1.40, 1.53). Using data only from round 5 we estimate a reproduction number of 1.06 (0.74, 1.46) with probability of 63% that R is greater than 1. Between rounds 4 and 5 there was a marked increase in unweighted prevalence at all ages. In the most recent data, prevalence was highest in the 18 to 24 yrs age group at 0.96% (0.68%, 1.36%). At 65+ yrs prevalence increased 7-fold between rounds 4 and 5 from 0.04% (0.03%, 0.07%) to 0.29% (0.23%, 0.37%). Prevalence increased in all regions between rounds 4 and 5, giving the highest unweighted prevalence in round 5 in the North West at 0.86% (0.69%, 1.06%). In Lond

Working paper

Riley S, Ainslie KEC, Eales O, Walters CE, Wang H, Atchison C, Fronterre C, Diggle PJ, Ashby D, Donnelly CA, Cooke G, Barclay W, Ward H, Darzi A, Elliott Pet al., 2020, Resurgence of SARS-CoV-2 in England: detection by community antigen surveillance, Publisher: Cold Spring Harbor Laboratory

<jats:title>Summary</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Based on cases and deaths, transmission of SARS-CoV-2 in England peaked in late March and early April 2020 and then declined until the end of June. Since the start of July, cases have increased, while deaths have continued to decrease.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>We report results from 594,000 swabs tested for SARS-CoV-2 virus obtained from a representative sample of people in England over four rounds collected regardless of symptoms, starting in May 2020 and finishing at the beginning of September 2020. Swabs for the most recent two rounds were taken between 24th July and 11th August and for round 4 between 22nd August and 7th September. We estimate weighted overall prevalence, doubling times between and within rounds and associated reproduction numbers. We obtained unweighted prevalence estimates by sub-groups: age, sex, region, ethnicity, key worker status, household size, for which we also estimated odds of infection. We identified clusters of swab-positive participants who were closer, on average, to other swab-positive participants than would be expected.</jats:p></jats:sec><jats:sec><jats:title>Findings</jats:title><jats:p>Over all four rounds of the study, we found that 72% (67%, 76%) of swab-positive individuals were asymptomatic at the time of swab and in the week prior. The epidemic declined between rounds 1 and 2, and rounds 2 and 3. However, the epidemic was increasing between rounds 3 and 4, with a doubling time of 17 (13, 23) days corresponding to an R value of 1.3 (1.2, 1.4). When analysing round 3 alone, we found that the epidemic had started to grow again with 93% probability. Using only the most recent round 4 data, we estimated a doubling time of 7.7 (5.5, 12.7) days, corresponding to an R value of 1.7 (1.4, 2.0). Cy

Working paper

Riley S, Atchison C, Ashby D, Donnelly CA, Barclay W, Cooke G, Ward H, Darzi A, Elliott Pet al., 2020, REal-time Assessment of Community Transmission (REACT) of SARS-CoV-2 virus: Study protocol, Wellcome Open Research, Vol: 5, Pages: 200-200

<ns3:p><ns3:bold>Background:</ns3:bold> England, UK has one of the highest rates of confirmed COVID-19 mortality globally. Until recently, testing for the SARS-CoV-2 virus focused mainly on healthcare and care home settings. As such, there is far less understanding of community transmission.</ns3:p><ns3:p> <ns3:bold>Protocol:</ns3:bold> The REal-time Assessment of Community Transmission (REACT) programme is a major programme of home testing for COVID-19 to track progress of the infection in the community.</ns3:p><ns3:p> REACT-1 involves cross-sectional surveys of viral detection (virological swab for RT-PCR) tests in repeated samples of 100,000 to 150,000 randomly selected individuals across England. This examines how widely the virus has spread and how many people are currently infected. The age range is 5 years and above. Individuals are sampled from the England NHS patient list.</ns3:p><ns3:p> REACT-2 is a series of five sub-studies towards establishing the seroprevalence of antibodies to SARS-CoV-2 in England as an indicator of historical infection. The main study (study 5) uses the same design and sampling approach as REACT-1 using a self-administered lateral flow immunoassay (LFIA) test for IgG antibodies in repeated samples of 100,000 to 200,000 adults aged 18 years and above. To inform study 5, studies 1-4 evaluate performance characteristics of SARS-CoV-2 LFIAs (study 1) and different aspects of feasibility, usability and application of LFIAs for home-based testing in different populations (studies 2-4).</ns3:p><ns3:p> <ns3:bold>Ethics and dissemination: </ns3:bold>The study has ethical approval. Results are reported using STROBE guidelines and disseminated through reports to public health bodies, presentations at scientific meetings and open access publications.</ns3:p><ns3:p> <ns3:bold>Conclusions: </ns3:bold>This study provides robust estimat

Journal article

Ward H, Atchison C, Whitaker M, Ainslie K, Elliot J, Okell L, Redd R, Ashby D, Donnelly C, Barclay W, Darzi A, Cooke G, Riley S, Elliot Pet al., 2020, Antibody prevalence for SARS-CoV-2 in England following first peak of the pandemic: REACT2 study in 100,000 adults, Publisher: bioRxiv

Background England, UK has experienced a large outbreak of SARS-CoV-2 infection. As in USA and elsewhere, disadvantaged communities have been disproportionately affected. Methods National REal-time Assessment of Community Transmission-2 (REACT-2) seroprevalence study using self-administered lateral flow immunoassay (LFIA) test for IgG among a random population sample of 100,000 adults over 18 years in England, 20 June to 13 July 2020. Results Completed questionnaires were available for 109,076 participants, yielding 5,544 IgG positive results and adjusted (for test performance), re-weighted (for sampling) prevalence of 6.0% (95% CI: 5.8, 6.1). Highest prevalence was in London (13.0% [12.3, 13.6]), among people of Black or Asian (mainly South Asian) ethnicity (17.3% [15.8, 19.1] and 11.9% [11.0, 12.8] respectively) and those aged 18-24 years (7.9% [7.3, 8.5]). Care home workers with client-facing roles had adjusted odds ratio of 3.1 (2.5, 3.8) compared with non-essential workers. One third (32.2%, [31.0-33.4]) of antibody positive individuals reported no symptoms. Among symptomatic cases, the majority (78.8%) reported symptoms during the peak of the epidemic in England in March (31.3%) and April (47.5%) 2020. We estimate that 3.36 million (3.21, 3.51) people have been infected with SARS-CoV-2 in England to end June 2020, with an overall infection fatality ratio of 0.90% (0.86, 0.94). Conclusion The pandemic of SARS-CoV-2 infection in England disproportionately affected ethnic minority groups and health and care home workers. The higher risk of infection in these groups may explain, at least in part, their increased risk of hospitalisation and mortality from COVID-19.

Working paper

Atchison C, Pristerà P, Cooper E, Papageorgiou V, Redd R, Piggin M, Flower B, Fontana G, Satkunarajah S, Ashrafian H, Lawrence-Jones A, Naar L, Chigwende J, Gibbard S, Riley S, Darzi A, Elliott P, Ashby D, Barclay W, Cooke GS, Ward Het al., 2020, Usability and acceptability of home-based self-testing for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) antibodies for population surveillance, Clinical Infectious Diseases, Vol: 2020, Pages: 1-10, ISSN: 1058-4838

BACKGROUND: This study assesses acceptability and usability of home-based self-testing for SARS-CoV-2 antibodies using lateral flow immunoassays (LFIA). METHODS: We carried out public involvement and pilot testing in 315 volunteers to improve usability. Feedback was obtained through online discussions, questionnaires, observations and interviews of people who tried the test at home. This informed the design of a nationally representative survey of adults in England using two LFIAs (LFIA1 and LFIA2) which were sent to 10,600 and 3,800 participants, respectively, who provided further feedback. RESULTS: Public involvement and pilot testing showed high levels of acceptability, but limitations with the usability of kits. Most people reported completing the test; however, they identified difficulties with practical aspects of the kit, particularly the lancet and pipette, a need for clearer instructions and more guidance on interpretation of results. In the national study, 99.3% (8,693/8,754) of LFIA1 and 98.4% (2,911/2,957) of LFIA2 respondents attempted the test and 97.5% and 97.8% of respondents completed it, respectively. Most found the instructions easy to understand, but some reported difficulties using the pipette (LFIA1: 17.7%) and applying the blood drop to the cassette (LFIA2: 31.3%). Most respondents obtained a valid result (LFIA1: 91.5%; LFIA2: 94.4%). Overall there was substantial concordance between participant and clinician interpreted results (kappa: LFIA1 0.72; LFIA2 0.89). CONCLUSION: Impactful public involvement is feasible in a rapid response setting. Home self-testing with LFIAs can be used with a high degree of acceptability and usability by adults, making them a good option for use in seroprevalence surveys.

Journal article

Flower B, Brown JC, Simmons B, Moshe M, Frise R, Penn R, Kugathasan R, Petersen C, Daunt A, Ashby D, Riley S, Atchison C, Taylor GP, Satkunarajah S, Naar L, Klaber R, Badhan A, Rosadas C, Kahn M, Fernandez N, Sureda-Vives M, Cheeseman H, O'Hara J, Fontana G, Pallett SJC, Rayment M, Jones R, Moore LSP, Cherapanov P, Tedder R, McClure M, Ashrafian H, Shattock R, Ward H, Darzi A, Elliott P, Barclay W, Cooke Get al., 2020, Clinical and laboratory evaluation of SARS-CoV-2 lateral flow assays for use in a national COVID-19 sero-prevalence survey, Thorax, Vol: 75, Pages: 1082-1088, ISSN: 0040-6376

BackgroundAccurate antibody tests are essential to monitor the SARS-CoV-2 pandemic. Lateral flow immunoassays (LFIAs) can deliver testing at scale. However, reported performance varies, and sensitivity analyses have generally been conducted on serum from hospitalised patients. For use in community testing, evaluation of finger-prick self-tests, in non-hospitalised individuals, is required.MethodsSensitivity analysis was conducted on 276 non-hospitalised participants. All had tested positive for SARS-CoV-2 by RT-PCR and were ≥21d from symptom-onset. In phase I we evaluated five LFIAs in clinic (with finger-prick) and laboratory (with blood and sera) in comparison to a) PCR-confirmed infection and b) presence of SARS-CoV-2 antibodies on two “in-house” ELISAs. Specificity analysis was performed on 500 pre-pandemic sera. In phase II, six additional LFIAs were assessed with serum.Findings95% (95%CI [92.2, 97.3]) of the infected cohort had detectable antibodies on at least one ELISA. LFIA sensitivity was variable, but significantly inferior to ELISA in 8/11 assessed. Of LFIAs assessed in both clinic and laboratory, finger-prick self-test sensitivity varied from 21%-92% vs PCR-confirmed cases and 22%-96% vs composite ELISA positives. Concordance between finger-prick and serum testing was at best moderate (kappa 0.56) and, at worst, slight (kappa 0.13). All LFIAs had high specificity (97.2% - 99.8%).InterpretationLFIA sensitivity and sample concordance is variable, highlighting the importance of evaluations in setting of intended use. This rigorous approach to LFIA evaluation identified a test with high specificity (98.6% (95%CI [97.1, 99.4])), moderate sensitivity (84.4% with fingerprick (95%CI [70.5, 93.5])), and moderate concordance, suitable for seroprevalence surveys.

Journal article

Bowman LR, Kwok KO, Redd RE, Yi YY, Ward H, Wei WI, Atchison C, Wong SYSet al., 2020, Public perceptions and preventive behaviours during the early phase of the COVID-19 pandemic: a comparative study between Hong Kong and the United Kingdom, Publisher: Cold Spring Harbor Laboratory

<jats:title>ABSTRACT</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>In the absence of treatments and vaccines, the mitigation of COVID-19 relies on population engagement in non-pharmaceutical interventions, which is driven by their risk perception, anxiety level and knowledge. There may also be regional discrepancies in these drivers due to different historical exposure to disease outbreaks, government responses and cultures. As such, this study compared psycho-behavioral responses in two regions during the early phase of the pandemic.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Comparable cross-sectional surveys were administered among adults in Hong Kong (HK) and the United Kingdom (UK) during the early phase of each respective epidemic. Explanatory variables included demographics, risk perception and knowledge of COVID-19, anxiety level and preventive behaviors. Responses were weighted according to census data. Logistic regression models, including interaction terms to quantify regional differences, were used to assess the association between explanatory variables and the adoption of social-distancing measures.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Data of 3431 complete responses (HK:1663; UK:1768) were analysed. Perceived severity differed by region (HK: 97.5%; UK: 20.7%). A large proportion of respondents were abnormally/borderline anxious (HK:64.8%; UK:45.9%) and regarded direct contact with infected individuals as the transmission route of COVID-19 (HK:94.0-98.5%; UK:69.2-93.5%), with HK identifying additional routes. HK reported high levels of adoption of social-distancing (HK:32.4-93.7%; UK:17.6-59.0%) and mask-wearing (HK:98.8%; UK:3.1%). The impact of perceived severity and perceived ease of transmission on the adoption of social-distancing varied by region. In HK, they had no

Working paper

Riley S, Ainslie KEC, Eales O, Walters CE, Wang H, Atchison C, Diggle PJ, Ashby D, Donnelly CA, Cooke G, Barclay W, Ward H, Darzi A, Elliott Pet al., 2020, Transient dynamics of SARS-CoV-2 as England exited national lockdown, Publisher: Cold Spring Harbor Laboratory

<jats:title>Abstract</jats:title><jats:p>Control of the COVID-19 pandemic requires a detailed understanding of prevalence of SARS-CoV-2 virus in the population. Case-based surveillance is necessarily biased towards symptomatic individuals and sensitive to varying patterns of reporting in space and time. The real-time assessment of community transmission antigen study (REACT-1) is designed to overcome these limitations by obtaining prevalence data based on a nose and throat swab RT-PCR test among a representative community-based sample in England, including asymptomatic individuals. Here, we describe results comparing rounds 1 and 2 carried out during May and mid June / early July 2020 respectively across 315 lower tier local authority areas. In round 1 we found 159 positive samples from 120,620 tested swabs while round 2 there were 123 positive samples from 159,199 tested swabs, indicating a downwards trend in prevalence from 0.13% (95% CI, 0.11%, 0.15%) to 0.077% (0.065%, 0.092%), a halving time of 38 (28, 58) days, and an R of 0.89 (0.86, 0.93). The proportion of swab-positive participants who were asymptomatic at the time of sampling increased from 69% (61%, 76%) in round 1 to 81% (73%, 87%) in round 2. Although health care and care home workers were infected far more frequently than other workers in round 1, the odds were markedly reduced in round 2. Age patterns of infection changed between rounds, with a reduction by a factor of five in prevalence in 18 to 24 year olds. Our data were suggestive of increased risk of infection in Black and Asian (mainly South Asian) ethnicities. Using regional and detailed case location data, we detected increased infection intensity in and near London. Under multiple sensitivity analyses, our results were robust to the possibility of false positives. At the end of the initial lockdown in England, we found continued decline in prevalence and a shift in the pattern of infection by age and occupation. Community-b

Working paper

Pristera P, Papageorgiou V, Kaur M, Atchison C, Redd R, Bowman L, Piggin M, Ward Het al., 2020, Report 14: Online community involvement in COVID-19 research & outbreak response: early insights from a UK perspective

The Patient Experience Research Centre (PERC) at Imperial College London is developing research to explore and understand people’s views about, experiences of and behavioural responses to the outbreak in the UK and elsewhere. To guide that effort and to help inform COVID-19 research and responses more broadly - for example in mathematical modelling and policy - PERC launched an online community involvement initiative that sought rapid, early insight from members of the public and aimed to establish a network for ongoing community engagement.Priority areas for COVID-19 research Vaccine development was considered the most urgent research priority for many respondents. Social studies exploring the public’s experiences, risk perceptions and behaviours during this outbreak were necessary and important according to 95% of the respondents. Such research could:Improve the way the current outbreak response is planned and implemented;Improve the way information and guidance is provided to and understood by the public;Optimise the support provided to communities and vulnerable groups; andImprove future outbreak preparedness.Other recommended areas of research included:Understanding the role of the media in influencing how people react and respond;Furthering our basic understanding of the virus – how it spreads, who it affects the most and why, and whether people achieve and maintain immunity after being infected;Critiquing the UK’s response to the pandemic against that of other countries; andEnsuring lessons can be learnt from this outbreak to better equip us for future outbreaks, and public health emergencies in general.Key unmet needs amongst communities The main challenges described by respondents were ineffective communication, including access to information and information overload; and conflicting guidance and misinformation. Respondents’ described feelings of concern, confusion and, in some cases, panic as a result of these communication a

Report

Atchison CJ, Bowman L, Vrinten C, Redd R, Pristera P, Eaton JW, Ward Het al., 2020, Perceptions and behavioural responses of the general public during the COVID-19 pandemic: A cross-sectional survey of UK Adults, Publisher: medRxiv

Objective: To examine risk perceptions and behavioural responses of the UK adult population during the early phase of the COVID-19 epidemic in the UK. Design: A cross-sectional survey Setting: Conducted with a nationally representative sample of UK adults within 48 hours of the UK Government advising the public to stop non-essential contact with others and all unnecessary travel. Participants: 2,108 adults living in the UK aged 18 years and over. Data were collected between March 17 and 18 2020. Main outcome measures: Descriptive statistics for all survey questions, including the number of respondents and the weighted percentages. Logistic regression was used to identify sociodemographic variation in: (1) adoption of social-distancing measures, (2) ability to work from home, and (3) willingness and (4) ability to self-isolate. Results Overall, 1,992 (94.2%) respondents reported taking at least one preventive measure: 85.8% washed their hands with soap more frequently; 56.5% avoided crowded areas and 54.5% avoided social events. Adoption of social-distancing measures was higher in those aged over 70 compared to younger adults aged 18 to 34 years (aOR:1.9; 95% CI:1.1 to 3.4). Those with the lowest household income were six times less likely to be able to work from home (aOR:0.16; 95% CI:0.09 to 0.26) and three times less likely to be able to self-isolate (aOR:0.31; 95% CI:0.16 to 0.58). Ability to self-isolate was also lower in black and minority ethnic groups (aOR:0.47; 95% CI:0.27 to 0.82). Willingness to self-isolate was high across all respondents. Conclusions The ability to adopt and comply with certain NPIs is lower in the most economically disadvantaged in society. Governments must implement appropriate social and economic policies to mitigate this. By incorporating these differences in NPIs among socio-economic subpopulations into mathematical models of COVID-19 transmission dynamics, our modelling of epidemic outcomes and response to COVID-19 can be improved.

Working paper

Atchison C, Bowman L, Eaton J, Imai N, Redd R, Pristera P, Vrinten C, Ward Het al., 2020, Report 10: Public response to UK Government recommendations on COVID-19: population survey, 17-18 March 2020, 10

On Monday 16th March 2020 the UK government announced new actions to control COVID-19. These recommendations directly affected the entire UK population, and included the following: stop non-essential contact with others; stop all unnecessary travel; start working from home where possible; avoid pubs, clubs, theatres and other such social venues; and to isolate at home for 14 days if anyone in the household has a high temperature or a new and continuous cough. To capture public sentiment towards these recommendations, a YouGov survey was commissioned by the Patient Experience Research Centre (PERC), Imperial College London. The survey was completed by 2,108 UK adults between the dates of 17th – 18th March 2020. The survey results show the following:• 77% reported being worried about the COVID-19 outbreak in the UK.• 48% of adults who have not tested positive for COVID-19 believe it is likely they will be infected at some point in the future.• 93% of adults reported personally taking at least one measure to protect themselves from COVID-19 infection, including:o 83% washed their hands more frequently;o 52% avoided crowded areas;o 50% avoided social events;o 36% avoided public transport;o 31% avoided going out;o 11% avoided going to work;o 28% avoided travel to areas outside the UK.• There is high reported ability and willingness to self-isolate for 7 days* if advised to do so by a health professional (88%).• However only 44% reported being able to work from home. This was higher among managerial and professional workers (60%) than manual, semi-skilled, and casual workers (19%)^, reflecting less flexible job roles for manual and lower grade workers. • 71% reported changing behaviour in response to government guidance. The figure (53%) was lower for young adults (18-24 year-olds).• Hand washing (63%), avoiding persons with symptoms (61%), and covering your sneeze (53%) were more likely to be perceived as ‘very effective&rs

Report

Zhang X-S, Smith A, Patel B, Anderson C, Pomeroy L, Higgins G, O'Moore E, Chow Y, Atchison Cet al., 2020, New approaches to controlling an outbreak of chickenpox in a large immigration detention setting in England: the role of serological testing and mathematical modelling, EPIDEMIOLOGY AND INFECTION, Vol: 148, ISSN: 0950-2688

Journal article

Ward H, Cooke G, Atchison C, Whitaker M, Elliott J, Moshe M, Brown JC, Flower B, Daunt A, Ainslie K, Ashby D, Donnelly C, Riley S, Darzi A, Barclay W, Elliott Pet al., 2020, Declining prevalence of antibody positivity to SARS-CoV-2: a community study of 365,000 adults

Background The prevalence and persistence of antibodies following a peak SARS-CoV-2 infection provides insights into its spread in the community, the likelihood of reinfection and potential for some level of population immunity.Methods Prevalence of antibody positivity in England, UK (REACT2) with three cross-sectional surveys between late June and September 2020. 365104 adults used a self-administered lateral flow immunoassay (LFIA) test for IgG. A laboratory comparison of LFIA results to neutralization activity in panel of sera was performed.Results There were 17,576 positive tests over the three rounds. Antibody prevalence, adjusted for test characteristics and weighted to the adult population of England, declined from 6.0% [5.8, 6.1], to 4.8% [4.7, 5.0] and 4.4% [4.3, 4.5], a fall of 26.5% [-29.0, −23.8] over the three months of the study. There was a decline between rounds 1 and 3 in all age groups, with the highest prevalence of a positive result and smallest overall decline in positivity in the youngest age group (18-24 years: −14.9% [-21.6, −8.1]), and lowest prevalence and largest decline in the oldest group (75+ years: −39.0% [-50.8, −27.2]); there was no change in antibody positivity between rounds 1 and 3 in healthcare workers (+3.45% [-5.7, +12.7]).The decline from rounds 1 to 3 was largest in those who did not report a history of COVID-19, (−64.0% [-75.6, −52.3]), compared to −22.3% ([-27.0, −17.7]) in those with SARS-CoV-2 infection confirmed on PCR.Discussion These findings provide evidence of variable waning in antibody positivity over time such that, at the start of the second wave of infection in England, only 4.4% of adults had detectable IgG antibodies using an LFIA. Antibody positivity was greater in those who reported a positive PCR and lower in older people and those with asymptomatic infection. These data suggest the possibility of decreasing population immunity and increasing risk of rei

Working paper

Hasso-Agopsowicz M, Ladva CN, Lopman B, Sanderson C, Cohen AL, Tate JE, Riveros X, Henao-Restrepo AM, Clark A, Alkorta M, Atchison C, Banajeh S, Becker-Dreps S, Benhafid M, Bhandari N, Bodhidatta L, Braeckman T, Bwogi J, Carmona RDCC, Cilla G, Contreras-Roldan I, Coulson B, Cunliffe NA, Dagan R, Givon N, Degiuseppe JI, Dhiman S, Dian Z, Diaz J, Dutta S, Krishnan T, Manna B, Fletcher-Lartey S, Fu C, Gendrel D, Ghenghesh KS, Mago GG, De Grazia S, Grimwood K, Groome M, Haque A, Heininger U, Houpt ER, Iturriza-Gomara M, Hungerford D, Jarquin CM, McCracken JP, Contreras IL, Cordon-Rosales C, Kaiser-Labusch P, Kang G, Kar S, Kiulia N, Kotloff K, Latipov R, Linhares A, Lorrot M, Mandile M, Mast C, Mathew MA, Matinon-Torres F, Matthijnssens J, Mladenova Z, Monini M, Montes M, Arana A, Motamedifar M, Najafi A, Nelson T, Nokes J, Ntoumi F, Numazaki K, O'Reilly C, Ochoa TJ, Page NA, Page AL, Langendorf C, Podkolzin AT, Quach C, Racz ML, De Rougemont A, Ruiz-Palacios GM, Saha SK, Saha S, Satter SM, Soares L, Sudarmo SM, Shigemura K, Shirakawa T, Athiyyah AF, Tagbo B, Tarr P, Klein E, Denno DM, Turner A, Uzoma EB, Vatosoa RR, Wandera EA, Wikswo M, Payne D, Yhu-Chering H, Yoshikawa T, Sugata K, Yuan Q, Liying L, Zaman K, Zhou X-N, Zhang S-X, Xu W, Serhan F, Nakamura T, Antoni S, Agocs M, Murray J, Cherian T, Mwenda JM, Weldegebriel G, Biey JNM, Cheikh D, Teleb N, Rahman HA, Ahmed H, Daniels D, Videbaek D, Wasley A, Singh S, de Oliveira L, Rey-Benito G, Sanwogou NJ, Liyanage J, Wijesinghe PR, Batmunkh N, Grabovac V, Fox K, Paladin FJ, Henschke Net al., 2019, Global Review of the Age Distribution of Rotavirus Disease in Children Aged < 5 Years Before the Introduction of Rotavirus Vaccination, CLINICAL INFECTIOUS DISEASES, Vol: 69, Pages: 1071-1078, ISSN: 1058-4838

Journal article

Nsanya MK, Atchison CJ, Bottomley C, Doyle AM, Kapiga SHet al., 2019, Modern contraceptive use among sexually active women aged 15-19 years in North-Western Tanzania: results from the Adolescent 360 (A360) baseline survey, BMJ OPEN, Vol: 9, ISSN: 2044-6055

Journal article

Doyle AM, Mulhern E, Rosen J, Appleford G, Atchison C, Bottomley C, Hargreaves JR, Weinberger Met al., 2019, Challenges and opportunities in evaluating programmes incorporating human-centred design: lessons learnt from the evaluation of Adolescents 360, Gates Open Research, Vol: 3, Pages: 1472-1472

<ns4:p>Adolescents 360 (A360) is a four-year initiative (2016–2020) to increase 15-19-year-old girls’ use of modern contraception in Nigeria, Ethiopia and Tanzania. The innovative A360 approach is led by human-centred design (HCD), combined with social marketing, developmental neuroscience, public health, sociocultural anthropology and youth engagement ‘lenses’, and aims to create context-specific, youth-driven solutions that respond to the needs of adolescent girls. The A360 external evaluation includes a process evaluation, quasi-experimental outcome evaluation, and a cost-effectiveness study. We reflect on evaluation opportunities and challenges associated with measuring the application and impact of this novel HCD-led design approach.</ns4:p><ns4:p> For the process evaluation, participant observations were key to capturing the depth of the fast-paced, highly-iterative HCD process, and to understand decision-making within the design process. The evaluation team had to be flexible and align closely with the work plan of the implementers. The HCD process meant that key information such as intervention components, settings, and eligible populations were unclear and changed over outcome evaluation and cost-effectiveness protocol development. This resulted in a more time-consuming and resource-intensive study design process. As much time and resources went into the creation of a new design approach, separating one-off “creation” costs versus those costs associated with actually implementing the programme was challenging. Opportunities included the potential to inform programmatic decision-making in real-time to ensure that interventions adequately met the contextualized needs in targeted areas.</ns4:p><ns4:p> Robust evaluation of interventions designed using HCD, a promising and increasingly popular approach, is warranted yet challenging. Future HCD-based initiatives should consider a phased evaluation

Journal article

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