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1.
J Infect ; 84(5): 675-683, 2022 05.
Article in English | MEDLINE | ID: covidwho-1788130

ABSTRACT

Background COVID-19 vaccines approved in the UK are highly effective in general population cohorts, however, data on effectiveness amongst individuals with clinical conditions that place them at increased risk of severe disease are limited. Methods We used GP electronic health record data, sentinel virology swabbing and antibody testing within a cohort of 712 general practices across England to estimate vaccine antibody response and vaccine effectiveness against medically attended COVID-19 amongst individuals in clinical risk groups using cohort and test-negative case control designs. Findings There was no reduction in S-antibody positivity in most clinical risk groups, however reduced S-antibody positivity and response was significant in the immunosuppressed group. Reduced vaccine effectiveness against clinical disease was also noted in the immunosuppressed group; after a second dose, effectiveness was moderate (Pfizer: 59.6%, 95%CI 18.0-80.1%; AstraZeneca 60.0%, 95%CI -63.6-90.2%). Interpretation In most clinical risk groups, immune response to primary vaccination was maintained and high levels of vaccine effectiveness were seen. Reduced antibody response and vaccine effectiveness were seen after 1 dose of vaccine amongst a broad immunosuppressed group, and second dose vaccine effectiveness was moderate. These findings support maximising coverage in immunosuppressed individuals and the policy of prioritisation of this group for third doses.


Subject(s)
COVID-19 Vaccines , COVID-19 , COVID-19/prevention & control , Humans , Immunity , SARS-CoV-2
2.
EClinicalMedicine ; 45: 101319, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1704577

ABSTRACT

BACKGROUND: The role of educational settings in SARS-CoV-2 infection and transmission remains controversial. We investigated SARS-CoV-2 infection, seroprevalence, and seroconversion rates in secondary schools during the 2020/21 academic year, which included the emergence of the more transmissible alpha and delta variants, in England. METHODS: The UK Health Security Agency (UKHSA) initiated prospective surveillance in 18 urban English secondary schools. Participants had nasal swabs for SARS-CoV-2 RT-PCR and blood sampling for SARS-CoV-2 nucleoprotein and spike protein antibodies at the start (Round 1: September-October 2020) and end (Round 2: December 2020) of the autumn term, when schools reopened after national lockdown was imposed in January 2021 (Round 3: March-April 2021), and end of the academic year (Round 4: May-July 2021). FINDINGS: We enrolled 2314 participants (1277 students, 1037 staff; one participant had missing data for PCR testing). In-school testing identified 31 PCR-positive participants (20 students, 11 staff). Another 247 confirmed cases (112 students, 135 staff) were identified after linkage with national surveillance data, giving an overall positivity rate of 12.0% (278/2313; staff: 14.1%, 146/1037 vs students: 10.3%, 132/1276; p = 0.006). Trends were similar to national infection data. Nucleoprotein-antibody seroprevalence increased for students and staff between Rounds 1 and 3 but were similar between Rounds 3 and 4, when the delta variant was the dominant circulating strain. Overall, Nucleoprotein-antibody seroconversion was 18.4% (137/744) in staff and 18.8% (146/778) in students, while Spike-antibody seroconversion was higher in staff (72.8%, 525/721) than students (21.3%, 163/764) because of vaccination. INTERPRETATION: SARS-CoV-2 infection rates in secondary schools remained low when community infection rates were low, even as the delta variant was emerging in England. FUNDING: This study was funded by the UK Department of Health and Social Care.

3.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-321615

ABSTRACT

Background: The SARS-CoV-2 Delta variant is highly transmissible and spreading globally but a detailed understanding of community transmission risks in highly vaccinated populations is lacking.Methods: Between September 2020 and August 2021, we recruited 510 community contacts of 422 UK COVID-19 cases to a cohort study. A total of 7194 upper respiratory tract (URT) samples were tested from sequential daily sampling of participants for up to 20 days. We analysed transmission risk by vaccination status for 139 contacts exposed to the Delta variant. We compared viral load (VL) trajectories from fully-vaccinated cases of Delta infection (n=19) with unvaccinated Delta (n=10), Alpha (n=39) and pre-Alpha (n=49) infections.Findings: The household secondary attack rate for fully-vaccinated contacts exposed to Delta was 19.7% (95%CI:11.6-31.3%), compared with 35.7% (95%CI:16.4-61.2%) in the unvaccinated. One third of infections in Delta-exposed contacts arose from fully-vaccinated index cases and one half of infected contacts were also fully-vaccinated. Seven transmission events between fully vaccinated index-contact pairs occurred. Genomic analysis confirmed transmission pathways between fully-vaccinated individuals within three households. Peak VL was similar in vaccinated and unvaccinated individuals with Delta variant infection but vaccinated Delta cases saw significantly faster VL decline than unvaccinated Alpha or Delta cases. Within infected individuals, faster VL growth was correlated with higher peak VL and slower decline.Interpretation: Although vaccination reduces the risk of Delta infection and causes some changes to viral kinetics, fully-vaccinated individuals with breakthrough infections have peak URT VL similar to unvaccinated cases and can efficiently transmit infection in household settings, including to fully vaccinated contacts.Funding: National Institute for Health Research (Award:NIHR200927)Declaration of Interest: The authors declare no relevant conflicts.Ethical Approval: The study was approved by the Health Research Authority (Research Ethics Committee reference: 20/NW/0231).

4.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-296775

ABSTRACT

ABSTRACT Background The role of educational settings on SARS-CoV-2 infection and transmission remains controversial. We investigated SARS-CoV-2 infection, seroprevalence and seroconversions rates in secondary schools during the 2020/21 academic year, which included the emergence of the more transmissible Alpha and Delta variants, in England. Methods The UK Health Security Agency (UKHSA) initiated prospective surveillance in 18 urban English secondary schools. Participants had nasal swabs for SARS-CoV-2 RT-PCR and blood sampling for SARS-CoV-2 Nucleoprotein and Spike protein antibodies at the start (Round 1: September-October 2020) and end (Round 2: December 2021) of the autumn term, when schools reopened after national lockdown was imposed in January 2021 (Round 3: March-April) and end of the academic year (Round 4: May-July). Findings We enrolled 2,314 participants (1277 students, 1037 staff). In-school testing identified 31 PCR-positive participants (20 students, 11 staff). Another 247 confirmed cases (112 students, 135 staff) were identified after linkage with national surveillance data, giving an overall positivity rate of 12.0% (278/2313;staff [14.1%, 146/1037] vs students [10.3%, 132/1276;p=0.006). Nucleoprotein-antibody seroprevalence increased for students and staff between Rounds 1-3 but changed little in Round 4, when the Delta variant was the dominant circulating strain. Overall, Nucleoprotein-antibody seroconversion was 18.4% (137/744) in staff and 18.8% (146/778) in students, while Spike-antibody seroconversion was higher in staff (72.8% (525/721) than students (21.3%, 163/764) because of vaccination. Interpretation SARS-CoV-2 infection and transmission in secondary schools remained low when community infection rates were low because of national lockdown, even after the emergence of the Delta variant Funding DHSC

5.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-293893

ABSTRACT

Background: There are few epidemiological studies of community cases in the current coronavirus-2019 (COVID-19) pandemic. We report on the first 500 COVID-19 cases identified through United Kingdom primary care surveillance and describe risk factors for testing COVID-19 positive. <br><br>Methods: The Oxford-Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC), is a nationally representative primary care sentinel network sharing pseudonymised data, including virological test data for COVID-19. We used multivariable logistic regression models with multiple imputation to identify risk factors for positive COVID-19 tests within this surveillance programme. <br><br>Findings: We identified 3,802 COVID-19 results between 28/01/20 and 04/04/2020, 587 were positive. Greater odds of testing COVID-19 positive included: working-age people (40-64years) and older age, (≥75 years) versus 0-17 year olds (adjusted odds ratio [aOR] 5.26, 95%CI:3.26-8.49 and 5.17,95%CI:2.99-8.92, respectively);male gender (aOR 1.56, 95%CI:1.28-1.90);black and mixed ethnicity compared with white (aOR 4.55, 95%CI:2.55-8.10 and 1.84 95%CO:1.1-3.14, respectively));urban compared with rural areas (aOR 4.58, 95%CI:3.57-5.88);people with chronic kidney disease (CKD) (aOR 1.88, 95%CI:1.29-2.75) and increasing body mass index (aOR 1.02, 95%CI:1.00-1.03). People in the least deprived deprivation quintile had lower odds of a positive test (aOR 0.49 95%CI:0.36-0.65) as did current smokers (aOR 0.53, 95%CI:0.38-0.74). <br><br>Interpretation: A positive COVID-19 test result in primary care was associated with similar risk factors for severe outcomes seen in hospital settings, with the exception of smoking. We provide early evidence of potential sociodemographic factors associated with a positive test, including ethnicity, deprivation, population density, and CKD. <br><br>Funding Statement: Public Health England provides the core funding for RCGP RSC, no specific funding was provided for this analysis.<br><br>Declaration of Interests: The authors have no competing interests. SdeL is the Director of the Oxford RCGP RSC, RB, JS, FF, EK and GH are part funded by PHE;and CO and AC by a Wellcome Biomedical resources grant (212763/Z/18/Z). JD is funded by Wellcome Trust (216421/Z/19/Z).<br><br>Ethics Approval Statement: This study was approved by the RCGP RSC study approval committee and was classified as a study of “usual practice”. Therefore, no further ethical approval was required.

6.
Lancet Healthy Longev ; 2(12): e811-e819, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1541059

ABSTRACT

BACKGROUND: Understanding the duration of protection and risk of reinfection after natural infection is crucial to planning COVID-19 vaccination for at-risk groups, including care home residents, particularly with the emergence of more transmissible variants. We report on the duration, neutralising activity, and protection against the alpha variant of previous SARS-CoV-2 infection in care home residents and staff infected more than 6 months previously. METHODS: We did this prospective observational cohort surveillance in 13 care homes in Greater London, England. All staff and residents were included. Staff and residents had regular nose and throat screening for SARS-CoV-2 by RT-PCR according to national guidelines, with ad hoc testing of symptomatic individuals. From January, 2021, antigen lateral flow devices were also used, but positive tests still required RT-PCR confirmation. Staff members took the swab samples for themselves and the residents. The primary outcome was SARS-CoV-2 RT-PCR positive primary infection or reinfection in previously infected individuals, as determined by previous serological testing and screening or diagnostic RT-PCR results. Poisson regression and Cox proportional hazards models were used to estimate protective effectiveness of previous exposure. SARS-CoV-2 spike, nucleoprotein, and neutralising antibodies were assessed at multiple timepoints as part of the longitudinal follow-up. FINDINGS: Between April 10 and Aug 3, 2020, we recruited and tested 1625 individuals (933 staff and 692 residents). 248 participants were lost to follow-up (123 staff and 125 residents) and 1377 participants were included in the follow-up period to Jan 31, 2021 (810 staff and 567 residents). There were 23 reinfections (ten confirmed, eight probable, five possible) in 656 previously infected individuals (366 staff and 290 residents), compared with 165 primary infections in 721 susceptible individuals (444 staff and 277 residents). Those with confirmed reinfections had no or low neutralising antibody concentration before reinfection, with boosting of titres after reinfection. Kinetics of binding and neutralising antibodies were similar in older residents and younger staff. INTERPRETATION: SARS-CoV-2 reinfections were rare in older residents and younger staff. Protection from SARS-CoV-2 was sustained for longer than 9 months, including against the alpha variant. Reinfection was associated with no or low neutralising antibody before reinfection, but significant boosting occurred on reinfection. FUNDING: Public Health England.

7.
J Infect ; 83(5): 573-580, 2021 11.
Article in English | MEDLINE | ID: covidwho-1527750

ABSTRACT

OBJECTIVES: We assessed SARS-CoV-2 infection, seroprevalence and seroconversion in students and staff when secondary schools reopened in March 2021. METHODS: We initiated SARS-CoV-2 surveillance in 18 secondary schools across six regions in September 2020. Participants provided nasal swabs for RT-PCR and blood samples for SARS-CoV-2 antibodies at the beginning (September 2020) and end (December 2020) of the autumn term and at the start of the spring term (March 2021). FINDINGS: In March 2021, 1895 participants (1100 students:795 staff) were tested; 5.6% (61/1094) students and 4.4% (35/792) staff had laboratory-confirmed SARS-CoV-2 infection from December 2020-March 2021. Nucleoprotein-antibody seroprevalence was 36.3% (370/1018) in students and 31.9% (245/769) in staff, while spike-antibody prevalence was 39.5% (402/1018) and 59.8% (459/769), respectively, similar to regional community seroprevalence. Between December 2020 and March 2021, 14.8% (97/656; 95%CI: 12.2-17.7) students and 10.0% (59/590; 95%CI: 7.7-12.7) staff seroconverted. Weekly seroconversion rates were similar from September to December 2020 (8.0/1000) and from December 2020 to March 2021 (7.9/1000; students: 9.3/1,000; staff: 6.3/1,000). INTERPRETATION: By March 2021, a third of secondary school students and staff had evidence of prior infection based on N-antibody seropositivity, and an additional third of staff had evidence of vaccine-induced immunity based on S-antibody seropositivity.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Prospective Studies , Schools , Seroconversion , Seroepidemiologic Studies , Students
9.
Euro Surveill ; 26(29)2021 07.
Article in English | MEDLINE | ID: covidwho-1323061

ABSTRACT

We measured COVID-19 vaccine effectiveness (VE) against symptomatic SARS-CoV-2 infection at primary care/outpatient level among adults ≥ 65 years old using a multicentre test-negative design in eight European countries. We included 592 SARS-CoV-2 cases and 4,372 test-negative controls in the main analysis. The VE was 62% (95% CI: 45-74) for one dose only and 89% (95% CI: 79-94) for complete vaccination. COVID-19 vaccines provide good protection against COVID-19 presentation at primary care/outpatient level, particularly among fully vaccinated individuals.


Subject(s)
COVID-19 , SARS-CoV-2 , Adult , Aged , COVID-19 Vaccines , Europe , Humans , Primary Health Care
10.
EClinicalMedicine ; 37: 100948, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1272390

ABSTRACT

BACKGROUND: Older children have higher SARS-CoV-2 infection rates than younger children. We investigated SARS-CoV-2 infection, seroprevalence and seroconversion rates in staff and students following the full reopening of all secondary schools in England. METHODS: Public Health England (PHE) invited secondary schools in six regions (East and West London, Hertfordshire, Derbyshire, Manchester and Birmingham) to participate in SARS-CoV-2 surveillance during the 2020/21 academic year. Participants had nasal swabs for RT-PCR and blood samples for SARS-CoV-2 antibodies at the beginning (September 2020) and end (December 2020) of the autumn term. Multivariable logistic regression was used to assess independent risk factors for seropositivity and seroconversion. FINDINGS: Eighteen schools in six regions enrolled 2,209 participants, including 1,189 (53.8%) students and 1,020 (46.2%) staff. SARS-CoV-2 infection rates were not significantly different between students and staff in round one (5/948; [0.53%] vs. 2/876 [0.23%]; p = 0.46) or round two (10/948 [1.05%] vs. 7/886 [0.79%]; p = 0.63), and similar to national prevalence. None of four and 7/15 (47%) sequenced strains in rounds 1 and 2 were the highly transmissible SARS-CoV-2 B.1.1.7 variant. In round 1, antibody seropositivity was higher in students than staff (114/893 [12.8%] vs. 79/861 [9.2%]; p = 0.016), but similar in round 2 (117/893 [13.1%] vs.117/872 [13.3%]; p = 0.85), comparable to local community seroprevalence. Between the two rounds, 8.7% (57/652) staff and 6.6% (36/549) students seroconverted (p = 0.16). INTERPRETATION: In secondary schools, SARS-CoV-2 infection, seropositivity and seroconversion rates were similar in staff and students, and comparable to local community rates. Ongoing surveillance will be important for monitoring the impact of new variants in educational settings.

11.
American Association for Adult and Continuing Education ; 2021.
Article in English | ProQuest Central | ID: covidwho-1227422

ABSTRACT

Since the spring of 2020, the pandemic has dominated public discourse. Using a public health critical race praxis research approach, our team interviewed a diverse group of individuals to elicit stories about their knowledge, attitudes, and responses to COVID-19. We used health belief model constructs and critical race theory tenets to evaluate race and ethnicity's influence and implications in reactions to the pandemic. Findings include the ordinariness of racism and colorblindness in assessing the susceptibility and severity of COVID19 and its risk factors. Including social determinants of health in the core curriculum of cross-disciplinary education programs emphasizes the impact of public health disparities and may reduce colorblindness and ordinariness. [For the complete volume, "American Association for Adult and Continuing Education Inaugural 2020 Conference Proceedings (Online, October 27-30, 2020)," see ED611534.]

12.
Influenza Other Respir Viruses ; 15(5): 599-607, 2021 09.
Article in English | MEDLINE | ID: covidwho-1214794

ABSTRACT

BACKGROUND: During 2009-2010, pandemic influenza A (H1N1) pdm09 virus (pH1N1) infections in England occurred in two epidemic waves. Reasons for a reported increase in case-severity during the second wave are unclear. METHODS: We analysed hospital-based surveillance for patients with pH1N1 infections in England during 2009-2010 and linked national data sets to estimate ethnicity, socio-economic status and death within 28 days of admission. We used multivariable logistic regression to assess whether changes in demographic, clinical and management characteristics of patients could explain an increase in ICU admission or death, and accounted for missing values using multiple imputation. RESULTS: During the first wave, 54/960 (6%) hospitalised patients required intensive care and 21/960 (2%) died; during the second wave 143/1420 (10%) required intensive care and 55/1420 (4%) died. In a multivariable model, during the second wave patients were less likely to be from an ethnic minority (OR 0.33, 95% CI 0.26-0.42), have an elevated deprivation score (OR 0.75, 95% CI 0.68-0.83), have known comorbidity (OR 0.78, 95% CI 0.63-0.97) or receive antiviral therapy ≤2 days before onset (OR 0.72, 95% CI 0.56-0.92). Increased case-severity during the second wave was not explained by changes in demographic, clinical or management characteristics. CONCLUSIONS: Monitoring changes in patient characteristics could help target interventions during multiple waves of COVID-19 or a future influenza pandemic. To understand and respond to changes in case-severity, surveillance is needed that includes additional factors such as admission thresholds and seasonal coinfections.


Subject(s)
Epidemics , Influenza A Virus, H1N1 Subtype , Influenza, Human , Adolescent , Adult , England/epidemiology , Epidemics/history , Female , History, 21st Century , Hospitalization , Humans , Influenza, Human/epidemiology , Male , Middle Aged , Minority Groups , Young Adult
13.
Lancet Reg Health Eur ; 3: 100038, 2021 Apr.
Article in English | MEDLINE | ID: covidwho-1192394

ABSTRACT

BACKGROUND: Care homes have been disproportionately affected by the COVID-19 pandemic. We investigated the potential role of asymptomatic infection and silent transmission in London care homes that reported no cases of COVID-19 during the first wave of the pandemic. METHODS: Five care homes with no cases and two care homes reporting a single case of COVID-19 (non-outbreak homes) were investigated with nasal swabbing for SARS-CoV-2 RT-PCR and serology for SARS-CoV-2 antibodies five weeks later. Whole genome sequencing (WGS) was performed on RT-PCR positive samples. Serology results were compared with those of six care homes with recognised outbreaks. FINDINGS: Across seven non-outbreak homes, 718 (387 staff, 331 residents) individuals had a nasal swab and 651 (386 staff, 265 residents) had follow-up serology. Sixteen individuals (13 residents, 3 staff) in five care homes with no reported cases were RT-PCR positive (care home positivity rates, 0 to 7.6%) compared to 13 individuals (3.0 and 10.8% positivity) in two homes reporting a single case.Seropositivity across these seven homes varied between 10.7-56.5%, with four exceeding community seroprevalence in London (14.8%). Seropositivity rates for staff and residents correlated significantly (rs 0.84, [95% CI 0.51-0.95] p <0.001) across the 13 homes. WGS identified multiple introductions into some homes and silent transmission of a single lineage between staff and residents in one home. INTERPRETATION: We found high rates of asymptomatic infection and transmission even in care homes with no COVID-19 cases. The higher seropositivity rates compared to RT-PCR positivity highlights the true extent of the silent outbreak. FUNDING: PHE.

14.
Euro Surveill ; 26(11)2021 03.
Article in English | MEDLINE | ID: covidwho-1181332

ABSTRACT

BackgroundA multi-tiered surveillance system based on influenza surveillance was adopted in the United Kingdom in the early stages of the coronavirus disease (COVID-19) epidemic to monitor different stages of the disease. Mandatory social and physical distancing measures (SPDM) were introduced on 23 March 2020 to attempt to limit transmission.AimTo describe the impact of SPDM on COVID-19 activity as detected through the different surveillance systems.MethodsData from national population surveys, web-based indicators, syndromic surveillance, sentinel swabbing, respiratory outbreaks, secondary care admissions and mortality indicators from the start of the epidemic to week 18 2020 were used to identify the timing of peaks in surveillance indicators relative to the introduction of SPDM. This timing was compared with median time from symptom onset to different stages of illness and levels of care or interactions with healthcare services.ResultsThe impact of SPDM was detected within 1 week through population surveys, web search indicators and sentinel swabbing reported by onset date. There were detectable impacts on syndromic surveillance indicators for difficulty breathing, influenza-like illness and COVID-19 coding at 2, 7 and 12 days respectively, hospitalisations and critical care admissions (both 12 days), laboratory positivity (14 days), deaths (17 days) and nursing home outbreaks (4 weeks).ConclusionThe impact of SPDM on COVID-19 activity was detectable within 1 week through community surveillance indicators, highlighting their importance in early detection of changes in activity. Community swabbing surveillance may be increasingly important as a specific indicator, should circulation of seasonal respiratory viruses increase.


Subject(s)
COVID-19/prevention & control , Epidemiological Monitoring , Physical Distancing , COVID-19/epidemiology , Humans , United Kingdom/epidemiology
15.
Diagn Progn Res ; 5(1): 4, 2021 Feb 08.
Article in English | MEDLINE | ID: covidwho-1069608

ABSTRACT

BACKGROUND: The aim of RApid community Point-of-care Testing fOR COVID-19 (RAPTOR-C19) is to assess the diagnostic accuracy of multiple current and emerging point-of-care tests (POCTs) for active and past SARS-CoV2 infection in the community setting. RAPTOR-C19 will provide the community testbed to the COVID-19 National DiagnOstic Research and Evaluation Platform (CONDOR). METHODS: RAPTOR-C19 incorporates a series of prospective observational parallel diagnostic accuracy studies of SARS-CoV2 POCTs against laboratory and composite reference standards in patients with suspected current or past SARS-CoV2 infection attending community settings. Adults and children with suspected current SARS-CoV2 infection who are having an oropharyngeal/nasopharyngeal (OP/NP) swab for laboratory SARS-CoV2 reverse transcriptase Digital/Real-Time Polymerase Chain Reaction (d/rRT-PCR) as part of clinical care or community-based testing will be invited to participate. Adults (≥ 16 years) with suspected past symptomatic infection will also be recruited. Asymptomatic individuals will not be eligible. At the baseline visit, all participants will be asked to submit samples for at least one candidate point-of-care test (POCT) being evaluated (index test/s) as well as an OP/NP swab for laboratory SARS-CoV2 RT-PCR performed by Public Health England (PHE) (reference standard for current infection). Adults will also be asked for a blood sample for laboratory SARS-CoV-2 antibody testing by PHE (reference standard for past infection), where feasible adults will be invited to attend a second visit at 28 days for repeat antibody testing. Additional study data (e.g. demographics, symptoms, observations, household contacts) will be captured electronically. Sensitivity, specificity, positive, and negative predictive values for each POCT will be calculated with exact 95% confidence intervals when compared to the reference standard. POCTs will also be compared to composite reference standards constructed using paired antibody test results, patient reported outcomes, linked electronic health records for outcomes related to COVID-19 such as hospitalisation or death, and other test results. DISCUSSION: High-performing POCTs for community use could be transformational. Real-time results could lead to personal and public health impacts such as reducing onward household transmission of SARS-CoV2 infection, improving surveillance of health and social care staff, contributing to accurate prevalence estimates, and understanding of SARS-CoV2 transmission dynamics in the population. In contrast, poorly performing POCTs could have negative effects, so it is necessary to undertake community-based diagnostic accuracy evaluations before rolling these out. TRIAL REGISTRATION: ISRCTN, ISRCTN14226970.

16.
Euro Surveill ; 26(5)2021 02.
Article in English | MEDLINE | ID: covidwho-1067625

ABSTRACT

Two London care homes experienced a second COVID-19 outbreak, with 29/209 (13.9%) SARS-CoV-2 RT-PCR-positive cases (16/103 residents, 13/106 staff). In those with prior SARS-CoV-2 exposure, 1/88 (1.1%) individuals (antibody positive: 87; RT-PCR-positive: 1) became PCR-positive compared with 22/73 (30.1%) with confirmed seronegative status. After four months protection offered by prior infection against re-infection was 96.2% (95% confidence interval (CI): 72.7-99.5%) using risk ratios from comparison of proportions and 96.1% (95% CI: 78.8-99.3%) using a penalised logistic regression model.


Subject(s)
Antibodies, Viral/blood , COVID-19/prevention & control , Disease Outbreaks/prevention & control , Nursing Homes/statistics & numerical data , Reinfection/prevention & control , SARS-CoV-2/genetics , Adult , Aged , Aged, 80 and over , COVID-19/blood , COVID-19/immunology , COVID-19 Serological Testing , Female , Humans , London , Male , Middle Aged , Pandemics , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/isolation & purification , Whole Genome Sequencing
19.
Euro Surveill ; 25(3)2020 01.
Article in English | MEDLINE | ID: covidwho-1004613

ABSTRACT

BACKGROUND: The ongoing outbreak of the recently emerged novel coronavirus (2019-nCoV) poses a challenge for public health laboratories as virus isolates are unavailable while there is growing evidence that the outbreak is more widespread than initially thought, and international spread through travellers does already occur. AIM: We aimed to develop and deploy robust diagnostic methodology for use in public health laboratory settings without having virus material available. METHODS: Here we present a validated diagnostic workflow for 2019-nCoV, its design relying on close genetic relatedness of 2019-nCoV with SARS coronavirus, making use of synthetic nucleic acid technology. RESULTS: The workflow reliably detects 2019-nCoV, and further discriminates 2019-nCoV from SARS-CoV. Through coordination between academic and public laboratories, we confirmed assay exclusivity based on 297 original clinical specimens containing a full spectrum of human respiratory viruses. Control material is made available through European Virus Archive - Global (EVAg), a European Union infrastructure project. CONCLUSION: The present study demonstrates the enormous response capacity achieved through coordination of academic and public laboratories in national and European research networks.


Subject(s)
Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Coronavirus Infections/virology , Coronavirus/classification , Coronavirus/genetics , COVID-19 Testing , COVID-19 Vaccines , Clinical Laboratory Techniques/methods , Coronavirus/isolation & purification , Disease Outbreaks , Humans , RNA, Viral/analysis , Real-Time Polymerase Chain Reaction/methods , Sensitivity and Specificity
20.
Lancet Reg Health Eur ; 2: 100015, 2021 Mar.
Article in English | MEDLINE | ID: covidwho-988715

ABSTRACT

BACKGROUND: Military personnel in enclosed societies are at increased risk of respiratory infections. We investigated an outbreak of Coronavirus Disease 2019 in a London Army barracks early in the pandemic. METHODS: Army personnel, their families and civilians had nasal and throat swabs for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) by reverse transcriptase -polymerase chain reaction (RT-PCR), virus isolation and whole genome sequencing, along with blood samples for SARS-CoV-2 antibodies. All tests were repeated 36 days later. FINDINGS: During the first visit, 304 (254 Army personnel, 10 family members, 36 civilians, 4 not stated) participated and 24/304 (8%) were SARS-CoV-2 RT-PCR positive. Infectious virus was isolated from 7/24 (29%). Of the 285 who provided a blood sample, 7% (19/285) were antibody positive and 63% (12/19) had neutralising antibodies. Twenty-two (22/34, 64%) individuals with laboratory-confirmed infection were asymptomatic. Nine SARS-CoV-2 RT-PCR positive participants were also antibody positive but those who had neutralising antibodies did not have infectious virus. At the second visit, no new infections were detected, and 13% (25/193) were seropositive, including 52% (13/25) with neutralising antibodies. Risk factors for SARS-CoV-2 antibody positivity included contact with a confirmed case (RR 25.2; 95% CI 14-45), being female (RR 2.5; 95% CI 1.0-6.0) and two-person shared bathroom (RR 2.6; 95% CI 1.1-6.4). INTERPRETATION: We identified high rates of asymptomatic SARS-CoV-2 infection. Public Health control measures can mitigate spread but virus re-introduction from asymptomatic individuals remains a risk. Most seropositive individuals had neutralising antibodies and infectious virus was not recovered from anyone with neutralising antibodies. FUNDING: PHE.

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