key: cord-1007802-25e44sc9
authors: Mbwogge, M.
title: Mass Testing with Contact Tracing Compared to Test and Trace for Effective Suppression of COVID-19 in the UK: A rapid review
date: 2021-01-15
journal: nan
DOI: 10.1101/2021.01.13.21249749
sha: 63a0ddcc6effb1098f6a8631341c6bfbfb4e117a
doc_id: 1007802
cord_uid: 25e44sc9

Abstract Background: Making testing available to everyone and tracing contacts might be the gold standard towards the control of COVID-19, particularly when significant transmissions are without symptoms. This study evaluated the effectiveness of mass testing and contact tracing in the suppression of COVID-19 compared to conventional Test and Trace in the UK. Design: A rapid review of available evidence Primary research question: Is there evidence that mass testing and tracing could suppress community spread of SARS-CoV-2 infections better than Test and Trace? Secondary research question: What is the proportion of asymptomatic cases of SARS-CoV-2 reported during mass testing interventions? Methods: Literature was searched in September through December 2020 in Google Scholar, Science Direct, Mendeley and PubMed. Results: Literature search yielded 286 articles from Google Scholar, 20 from Science Direct, 14 from Mendeley, 27 from Pubmed and 15 through manual search. Altogether 35 articles were included, making a sample size of close to a million participants. Conclusion: There was a very low level but promising evidence of 76{middle dot}9% (95% CI: 46{middle dot}2 - 95{middle dot}0, P=0{middle dot}09) majority vote in favour of the intervention under the primary objective. The overall proportion of asymptomatic cases among those tested positive and tested sample populations under the secondary objective was 40{middle dot}7% (95% CI:38{middle dot}8 - 42{middle dot}5) and 0{middle dot}01% (95% CI:0{middle dot}01 - 0{middle dot}012) respectively. Conventional test and trace should be superseded by a decentralised and regular mass rapid testing and contact tracing, championed by GP surgeries and low cost community services

UK's Test and Trace has been suboptimal in addressing the testing needs of those infected with SARS-CoV-2, let alone handling its new variant(1). The panic over rising cases and a potentially more dangerous second wave led to the creation of the National Institute for Health Protection (2) . Follow-up measures have been national lockdown, increased testing, tier system, furlough scheme and approval of the Pfizer, Oxford AstraZenaca and Moderna vaccines (3, 4) . As part of the above, about 56 million tests have been performed as at January 10, 2021, with about 1.3 million vaccinated (5) . The plans to launch the 100 billion pound "moonshot" programme will only sound as good if tests are delivered based on infections rather than on symptoms (6, 7) . I concur with the Director General of WHO that "you cannot fight a fire

Infections could better inform public policy and facilitate equitable rollout of vaccines.

While hoping that vaccines will proof as effective as deemed in the development of herd immunity, it is important not to lose sight of other control measures. Regular mass testing combined with contact tracing could be a novel control strategy not just to inform vaccination but also to guard against uncertainties arising from any new variant(9).

In this study Three modelling studies implemented in the UK dealing with mass testing were found. One of the models did a feasibility analysis of mass testing as a lockdown exit strategy. One model compared mass testing with symptom-based test and trace, while another model compared mass testing with symptom-based testing and isolation. There have been no realtime study in the UK comparing mass test and trace with the conventional test and trace system, reason being that mass testing and contact tracing was judged to be impossible. One systematic review was found, evaluating the effectiveness of universal screening for SARS-CoV-2 compared to no screening. This is the first review to the best of my knowledge that sought to evaluate the benefits of mass testing and contact tracing (hybrid strategy) compared to test and trace, in the control of COVID-19 in the UK. The proportion of asymptomatic cases has also been explored.

There is urgent need for a strategy that will identify SARS-CoV-2 carriers when their viral load is high and are most likely to be infectious. Real-time studies are needed to (1) get a true picture of disease burden, (2) validate various mass testing options and (3) better inform vaccination programme and other control measures. Figure 1 below shows the traditional "Test and Trace" system currently implemented in the UK, with a number of possible implications. Kindly refer to www.gov.uk for further details on how the Test and Trace system works(20). In the face of rising asymptomatic infectivity, the present TT delivery strategy can be categorised as "the cake not worth the candle", since the programme fails to determine the true burden of the disease.

The following can generally be observed from the above conventional system; 1) Individuals who are asymptomatic and presymptomatic are missed out (21) (22) (23) 2) People are generally afraid of quarantine and may shy away from TT (24) .

3) The decision of public safety about getting tested has been shifted to the public 4) Operational false positive estimates in the UK are currently unknown (25) 

Incubation 6 ) Test and trace depends on self-reported contacts which may be flawed 7) A proportion of the public is hesitant due to stigma surrounding data ethics (26) 8) TT is a shift away from Universal Health Coverage, amid a pandemic(27) 9) Long travel among others is a serious barrier to accessing test centres

The "Infectivity Problem" of COVID-19

The "infectivity problem" can be summarized into 1) Test ramp-up controversy, 2) TT system leakages, 3) Time-to-test paradox and 4) Inequitable test delivery and delays.

Test Ramp-up Controversy: This is the heated discussion and lockdown-related antagonism from the public, regarding the undesired positive correlation which was presumed inverse, between testing capacity and COVID-19 cases. The supposed endgame of test ramp-up was to contain the virus but countries have found themselves in the "opposite-of-things". This may be due to more cases now being detected as a result of increased testing or because the testing is not comprehensive and early enough to outweigh the viral shedding. This may culminate into the UK's "operation moonshot" controversy if testing rate continues to be less than infectivity rate (28) .

apparently was supposed to be tested but end up not being detected. This includes those with either unreported symptoms or not presenting for test, those sent home due to unavailability of tests, asymptomatic and presymptomatic individuals, unreported and untraced contacts, false negatives as well as the non-compliant to isolation and quarantine rules (29, 30) .

This refers to the conflicting interest of whether to test prior to symptoms or upon reported symptoms. The TT programme has been designed not to test people at very early stages of infection for fear of missing out the very cases it is meant to detect. The same is true when people are tested late (31, 32) . Research suggest that the serial interval of Covid-19 is shorter than the incubation period, indicating possible infectivity multiplier effect prior to symptom onset (33, 34) . This is further compounded by operational false positives and false negatives (25) .

This has to do with testing that is not delivered at point-of-care thereby eliminating a certain group of persons, delays in testing those reporting symptoms, test-to-results delay as well as contact tracing time lapse. The 

Is there evidence that testing irrespective of symptoms combined with tracing could suppress SARS-CoV-2 infections better than symptom-based testing and tracing?

What is the proportion of asymptomatic carriers of SARS-CoV-2 reported during mass testing interventions? is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint PubMed included "((((((((Mass testing for COVID-19 and "Contact tracing") OR (Mass testing for SARS-CoV-2 and "Contact tracing")) OR ("Test and trace")) OR ("Mass testing" and "symptom-based testing")) NOT (Animals)) NOT (HIV)) NOT (Influenza)) NOT (Ebola)) NOT (Cancer)". Finally, a search for "Mass testing for COVID-19" AND "contact tracing for COVID-19" OR "mass testing for SARS-CoV-2" AND "contact tracing for SARS-CoV-2" was done in Mendeley.

All articles published before the year 2020, non-English articles, articles whose full texts were not accessible, non-COVID-19 articles, articles on non-human subjects and non-mass testing articles. Given that this review was about detecting people currently infected, we excluded antibody studies. We also excluded editorials and protocols

Full text articles comparing testing irrespective of symptoms and contact tracing with symptom-based test and trace, as well as any partial comparison between the above.

Data extraction was done by a single reviewer who also did a detailed review of extracted data for individual studies. Extracted data included the study date, author, setting, study design, study objective, type of intervention, outcome, type of . CC-BY-NC 4.0 International license It is made available under a perpetuity.

is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted January 15, 2021. ; https://doi.org/10.1101/2021.01.13.21249749 doi: medRxiv preprint participants, strategies used, assumptions, data analysis, results, study limitations and bias.

In accordance with the study objective and logical framework, studies for synthesis were grouped according to outcome. In order to capture the studies whose interventions geared towards evaluating effects on outcomes of interest (38) . This made it easy to articulate synthesis to research questions.

Direction of effect was used as the standardize metric because there was a lack of precision specific to the effect of intervention and control in the results presented by different studies. This did not permit the calculation of summary statistics (39) . In light of the above, vote counting was the best match in synthesising the results. A sign test was used to indicate whether there was an evidence of effect. Equivocal effects between the intervention and control were considered to be distributed around the null hypothesis of no effect. This study made use of Synthesis Without Meta-Analysis (SWiM) reporting guidelines to report review results (40) .

Heterogeneity of studies was assessed following the GRADE risk assessment factors (41) . The lack of pooled effect size of modelling studies did not warrant us to perform a methodological diversity(42). Regarding the second objective however, variability was assessed by directly observing confidence intervals on plotted graphs.

Review findings were synthesised thematically. The quality of studies was critically appraised using most recent tools based on study design, in accordance with PHO MetQAT 1.0 quality appraisal tool(43,44). The methodology and risk of bias of modelling studies was assessed using Relevance and Credibility Assessment (RCA) tool proposed by Caro and colleagues(45). Cohort studies were assed using Critical Appraisal Skills Programme (CASP) tool(46). Specialist Unit for Review Evidence (SURE) tool was used to assess cross sectional studies(47). Studies were grouped into 6 main categories according to outcome, as outlined in the methodology section for easy analysis and synthesis. Quality of evidence generated by different studies was . CC-BY-NC 4.0 International license It is made available under a perpetuity.

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Tabular and graphical methods were deployed in presenting results. The GRADE summary of findings table was used to present certainty of evidence and a bar chart to present the effect direction of studies for the primary objective. In the secondary objective, forest plots were used to present the proportion of asymptomatic cases of SARS-CoV-2, using an excel model proposed by Neyeloff et al (91) 

In relation to the primary question, results of studies that evaluated the effectiveness of the intervention and control within the UK, with low risk of bias were prioritized because this was in line with the review objective. Real-time studies were also prioritized as these are more likely to be close to reality. Given the ambiguity in the use of contact tracing in most studies to include testing, studies evaluating the effectiveness of contact tracing provided they had a component of mass testing were included. Considering the novelty of the term Test and Trace used in this study, it is common place to find contact tracing based on symptom testing used in studies to be likened to Test and Trace in this review. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted January 15, 2021. ; https://doi.org/10.1101/2021.01.13.21249749 doi: medRxiv preprint A total of 35 articles that met the eligibility criteria were included. Table 1 below shows summary characteristics of included studies. A flow chart of how articles were selected can be seen in figure 3 below. Summary characteristics of studies excluded due to eligibility criteria are presented in supplement 1 of the appendix.

"Mass testing for COVID-19" AND "contact tracing for COVID-19" OR "mass testing for SARS-CoV-2" AND "contact tracing for SARS-CoV-2" (n = 14) is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

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The copyright holder for this this version posted January 15, 2021. ; https://doi.org/10.1101/2021.01.13.21249749 doi: medRxiv preprint

The lone included cohort study was rated at moderate risk of bias. A summary of the methodological assessment is presented in table 3 below; is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted January 15, 2021. ; https://doi.org/10.1101/2021.01.13.21249749 doi: medRxiv preprint

Vote counting was deployed as the method to synthesize results, in line with direction of effect that was used. Studies were prioritized based on their degree of bias in the reported evidence. The GRADE diagram for assessing the quality of evidence was used to grade the evidence presented by the different studies (85) . GRADE summary of findings table of the different studies can be seen in Table 5 below. (2020) and Hagan (2020) were voted in favour of the intervention. Three studies [25%, 95% BE CI: 5.5%-57.1%, p=0.15] including Grassly (2020), Sasmita (2020) and Bracis (2020) showed an unfavourable direction of effect and were voted in favour of the control. The body of evidence presented by the 11 modelling studies for this outcome was downgraded by 3 levels to very low. Firstly, because studies were neither randomized control trials nor real-time studies leading to one level down. An additional 2 levels downgrading was due to serious study bias, inter-study variation, imprecision and indirectness. The evidence from the lone cross-sectional study (Hagan, 2020) , was downgraded by 3 levels to "very low" as well. It was downgraded by one level because the study was not a randomized control trial. It was further downgraded by 2 levels due to methodological issues, imprecision and indirectness.

A single study found for this outcome (Paltiel, 2020) , was voted in favour of the intervention. This study was at high risk of bias. The quality of evidence was downgraded by one level given that it is not a randomized control trial. Being a model is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted January 15, 2021. ; https://doi.org/10.1101/2021.01.13.21249749 doi: medRxiv preprint based on assumptions coupled with study limitations, imprecision and indirectness, the evidence was further downgraded by 2 levels. Evidence was classed as very low.

I found no study addressing this outcome. However, a body of literature exist regarding safety and security concerns from the public with contact tracing (86) (87) (88) . Also, both nasopharyngeal and oropharyngeal swaps appear to be slightly invasive. The possible harms of mass testing have also been analysed by some authors (89) .

Again, no study was found regarding this outcome. Altmann and colleagues found a high level of acceptance for app-based contact tracing in their investigation across different countries including the UK(90).

There was no study for this outcome. It remains however clear that the test and trace system is not equitable(27). is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted January 15, 2021. ; https://doi.org/10.1101/2021.01.13.21249749 doi: medRxiv preprint (Hill, 2020 and Alsing, 2020) implemented in the UK, voted in favour of the intervention were judged to be at low risk of bias. The effect direction plot of different studies is shown in figure 4 below.

The generated GRADE evidence profile was used to present the synthesis findings regarding the primary objective as seen in table 6 below. Supplement 6 provides details of how the evidence for different outcomes was graded.

The results of 6 studies including Emery (2020) , Muzimoto (2020), Gorji (2020), Hill (2020) , Alsing (2020) and Paltiel (2020) were prioritized. These contributed more to the conclusion that the intervention was better because they were judged to be at low to moderate risk of bias. Three of the studies (Emery, 2020; Hill, 2020; Alsing, 2020) were judged to be at low risk of bias. Two of these (Hill, 2020 and Alsing, 2020) were both of the representative population and evaluated mass testing and contact tracing as a hybrid strategy, in line with the primary objective. Emery (2020) failed to consider contact tracing but compared the effect of testing based on symptoms and testing irrespective of symptoms. The direction of effect will not be different if contact tracing were to be integrated since contact tracing is contingent on testing. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

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A total of 21 cross sectional studies and 1 cohort study (33 reports as can be seen in figure 5 below. Two studies (Jameson, 2020 and Callaghan, 2020) neither detected any cases nor found asymptomatic carriers and so were excluded. is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

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Prevalence of asymptomatic SARS-CoV-2 was highest among homeless shelter residents [30.1%, 95% CI: 26.5-33.9], followed by care home residents [21%, 95% CI: 18 -24) and lowest among hospital patients [0%, 95% CI: 0.0 -1.2]. Besides screening in the general population, overall asymptomatic SARS-CoV-2 prevalence for all other settings was 3.9% (95% CI: 3.6 -4.2). Figure 6 

Four studies including Treibel (2020) , Brown (2020) , and Abeysuriya (2020) evaluated the outcome within the UK among hospital staff (Treibel, 2020 and is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted January 15, 2021. ; https://doi.org/10.1101/2021.01.13.21249749 doi: medRxiv preprint Brown, 2020) , in care homes and among pregnant women (Abeysuriya, 2020) . The proportion of asymptomatic cases among those tested positive ranged from 44% (95% CI: 35.5 -53.2) in care homes to 85.7% (95% CI: 42.1% -100%) in pregnancy. The overall proportion among detected cases was found to be 56.6% (95% CI: 49. 6 -63.4 ). Figure 7 below shows the relationship of asymptomatic proportion among detected cases and in sampled population in different settings within the UK.

Overall prevalence of asymptomatic cases within the UK was found to be 3.76% (95% CI: 3.1 -4.5) with rates ranging from 2.2% (95% CI: 1.6 -2.8) among hospital staff to 14.9% (95% CI: 11.5 -18.8) in care homes. Figure 7 above clearly demonstrates a higher overall rate among detected cases compared to that of all studies (z=4.53, p=0.00001 at p=0.05). Asymptomatic cases were 1.4 times more likely to be detected among positive cases in the UK than all studies put together. There was no significant difference between overall prevalence rate in the UK (3.76%) and all studies put together (3.9%), besides population screening (z = -0.37, p=0.71 at p=0.5)

All unreported confidence intervals were generated in SATA 14.2 (binomial exact) and exported to excel. The rule of three was applied to all studies with no outcome event (Jameson, 2020 and Callaghan, 2020) . is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

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Variations among studies included in the primary objective were mainly due to study population and setting, assumptions together with model structure. Evidence from countries that embarked on mass testing including Taiwan, Germany, Ireland, China and India support the fact that regular mass testing and contact tracing could be the game changer. The analysis by Peto et al (2020) showed that mass testing and contact tracing is by far more cost-effective than present test and trace, in line with the second outcome. Maslov (2020) on the contrary shares an opposing view in that even the slightest false positives will render random mass testing an unreliable policy (93) . While Maslov seem to be concerned with the inherent moral decadence of unjust isolation, it is rather better to be on a safe side than in a pool of false negatives and contented asymptomatic carriers. Identification of asymptomatic carriers is crucial because Viswanathan and colleagues also acknowledged that strategies based on symptom screening could miss between 40 -100% of infected persons (94) . Paying attention to asymptomatic infectiousness no matter how small the proportion may be is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted January 15, 2021. ; https://doi.org/10.1101/2021.01.13.21249749 doi: medRxiv preprint has also been underscored in Byambasuren et al (2020) (95) . This argument is also in accordance with the key messages and objectives of European Centre for Disease Prevention and Control, that whole population be tested in high transmission settings (96) .

This review also found an overall proportion of asymptomatic carriers among detected positive cases to be 40.7% (95% CI: 38.8-42.5) and 56.6% (95% CI: 49.6 -63.4) within the UK when stratified. Proportions across studies ranged from 28% among cases detected in the general population to 96.6% among care home staff with positive tests.

Also, asymptomatic SARS-CoV-2 prevalence was highest among residents in homeless shelter (30.1%) and lowest among hospital patients (0.0%). The 40.7% asymptomatic proportion among positive cases is in accordance with the 40 -45%

proportion estimated by Oran et al (97) . Clarke and colleagues reported a similar rate of 40.3% among haemodialysis patients (98) . This proportion is also concordant to that reported in Spain (40.5%) by Albalate et al (99) . The proportion of detected positive air travellers (83.6%) found in this review is higher than the 76.6% reported in Al-Qahtani et al(100) perhaps due to more awareness as the study was implemented at a much later date. Yanes-Lane reported an asymptomatic proportion of positive cases among care home residents (54%) just a little lower than the 60.2% reported in this review (101) . Notwithstanding the overarching reported high infectivity from asymptomatic individuals, this review reports rates ranging from 0.005 -1.2% in the population, similar to rates (1.5 -2%) reported by Wu et al (102) . The estimate that the proportion of asymptomatic SARS-CoV-2 among cases in the general population is 28% is in agreement with the community asymptomatic proportion of 28% in Beale et al (103) . In contrast, Petersen et al reported a community asymptomatic proportion that was three times higher (76.5% to 86.1%) (104) . This population level study was undertaken in the UK, contrary to those included in this review (Iceland, Italy and China). The largest population sample in this review (about a million) was a study done immediately after lockdown which could be the reason behind the low rates.

A majority of included studies were modelling studies which normally rely on assumptions that sometimes may hardly be achieved in real life. Expert knowledge . CC-BY-NC 4.0 International license It is made available under a perpetuity.

is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted January 15, 2021. ; https://doi.org/10.1101/2021.01.13.21249749 doi: medRxiv preprint was needed to evaluate the validation process of models and it cannot be guarantee that the conclusions on bias were as accurate as would have otherwise expected. The fact that this review went through a single reviewer might have introduced some bias in study selection and analysis. The variability in the understanding of mass testing by different researchers might have had an effect on the analysis as well. This review was language biased since the literature search was limited to English articles. Non peer reviewed articles (preprints) were included in the review thereby reducing the quality of evidence. This review was not registered with PROSPERO for standard systematic review practice and will be erroneous to be considered as such.

Controlling a virus whose manifestation is increasingly without signs is not about number of tests but about who needs to be tested. An appropriate public health strategy that will get the right people tested, at the right time and in the right place requires a community based and participatory approach which will not be without a greater cost burden. Among others, winning the quenched public confidence, ensuring data privacy, acceptability of the NHS app and equity of testing and contact tracing, use of rapid test, capacity building, effective monitoring of isolation and quarantine and programme sustainability are some of the considerations that will have to be made.

More real-time research is needed regarding the effectiveness of mass testing and contact tracing, for a better picture of disease burden and mitigation strategies.

This review sought to critically evaluate the evidence that mass testing and contact tracing is more effective in controlling local transmissions of COVID-19 in the UK, compared to conventional Test and Trace. It has demonstrated a very low level of promising evidence that mass testing and contact tracing could be more effective in bringing the virus under control and even more effective if combined with social distancing and face coverings. The implementation of test and trace has to be done at mass irrespective of symptoms with the local community, through GP surgeries, community health centres and local councils (105) . The proposal is for the present Test and Trace to be superseded by a decentralised and continuous mass testing is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

The copyright holder for this this version posted January 15, 2021. ; https://doi.org/10.1101/2021.01.13.21249749 doi: medRxiv preprint programme with rapid tests, championed by low-resource-need community services (106) . The following recommendations are therefore useful;

Capacitate GP surgeries and community health services to deliver mass testing at point-of-care.

Government should work in synergy with local councils for robust surveillance, isolation and quarantine(107). This showed major success in Germany (108, 109) Regular organizational and company-wide testing including the NHS, care homes and schools for the safe return of workforce and students (71, 74) .

Coronavirus testing should be a boarder control measure for all travellers (111, 112) .

Testing of prisoners, detainees and all those in congested accommodations (55) . The Lesbos camp testing in Greece led to more than 240 positive cases (113, 114) Sewage and environment related testing should be part of mitigation strategies

No funding was received for this study

The author declares no competing interest

There is no additional data . CC-BY-NC 4.0 International license It is made available under a perpetuity.

is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint

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Covid-19: Test and trace system is not fit for purpose, says Independent SAGE

National Institute for Health Protection takes over COVID-19 pandemic response from PHE

COVID-19 policy tracker [Internet]. The Health Foundation

Daily summary: Coronavirus in the UK

Pressing Go on Mass Testing | Institute for Global Change

Universal weekly testing as the UK COVID-19 lockdown exit strategy

/fulltext 8. WHO Director-General's opening remarks at the media briefing on COVID-19 -16

Public health management of persons having had contact with cases of novel coronavirus in the EU

Privacy-Preserving Automated Exposure Notification

Digital technology applications for contact tracing: the new promise for COVID-19 and beyond? Glob Heal Res Policy

Quarantine and Isolation

Test and Protect: A Step-By-Step Guide

Department of Health Northen Ireland. Covid-19 Test, Trace and Protect Strategy Saving lives by minimising SARS-CoV2 transmission in the community in Northern Ireland

Covid-19 mass testing programmes

Critical Appraisal: Using Evidence Guide

pdf?OpenElement management: the key to tackling the COVID-19 pandemic

Lancet Publishing Group

Department of Health and Social Care. NHS test and trace: how it works -GOV

Substantial undocumented infection facilitates the rapid dissemination of novel coronavirus (SARS-CoV-2)

Estimation of Unreported Novel Coronavirus (SARS-CoV-2) Infections from Reported Deaths: A Susceptible-Exposed-Infectious-Recovered-Dead Model

CMMID COVID-19 Working Group, et al. The contribution of asymptomatic SARS-CoV-2 infections to transmission on the Diamond Princess cruise ship

Infectious disease outbreak related stigma and discrimination during the COVID-19 pandemic: Drivers, facilitators, manifestations, and outcomes across the world

Impact of false-positives and false-negatives in the UK's COVID-19 RT-PCR testing programme

Can we fight COVID-19 without resorting to mass surveillance?

World Health Organization

Covid-19: Government plans to spend £100bn on expanding testing to 10 million a day

NHS Test and Trace performance tracker [Internet]. The Health Foundation

An imperfect tool: COVID-19 "test & trace" success relies on minimising the impact of false negatives and continuation of physical distancing. medRxiv

Variation in False-Negative Rate of Reverse Transcriptase Polymerase Chain Reaction-Based SARS-CoV-2 Tests by Time Since Exposure

Virological assessment of hospitalized patients with COVID-2019

Serial interval of novel coronavirus (COVID-19) infections

Covid-19: An efficient and effective test trace regime is not a numbers game

The conceptual framework and assessment methodology for the systematic reviews of community-based interventions for the prevention and control of infectious diseases of poverty

Infectious Diseases of Poverty

Characteristics of SARS-CoV-2 and COVID-19

Chapter 3: Defining the criteria for including studies and how they will be grouped for the synthesis

Chapter 6: Choosing effect measures and computing estimates of effect

Synthesis without meta-analysis (SWiM) in systematic reviews: Reporting guideline

Heterogeneity: what is it and why does it matter?

The effect of preventing subclinical transmission on the containment of COVID-19: Mathematical modeling and experience in Taiwan

Estimating the asymptomatic proportion of coronavirus disease 2019 (COVID-19) cases on board the Diamond Princess cruise ship

Optimal control on a mathematical model to pattern the progression of coronavirus disease 2019 (COVID-19) in Indonesia

The implications of silent transmission for the control of COVID-19 outbreaks

Widespread testing, case isolation and contact tracing may allow safe school reopening with continued moderate physical distancing: A modeling analysis of King County, WA data

The impact of digital contact tracing on the SARS-CoV-2 pandemic-a comprehensive 2 modelling study

Modelling SARS-CoV-2 transmission in a UK university setting

Smart Testing with Contact Counting Enhances Covid-19 Mitigation by Bluetooth App Based Contact Tracing

Containing Covid-19 outbreaks with spatially targeted short-term lockdowns and mass-testing

Mass Testing for SARS-CoV-2 in 16 Prisons and Jails -Six Jurisdictions

Assessment of SARS-CoV-2 Screening Strategies to Permit the Safe Reopening of College Campuses in the United States

Estimation of the asymptomatic ratio of novel coronavirus infections

Health Surveillance and Response to SARS-CoV-2 Mass Testing in Health Workers of a Large Italian Hospital in Verona, Veneto

COVID-19: PCR screening of asymptomatic health-care workers at London hospital

Lancet Publishing Group

Universal screening for SARS-CoV-2 in pregnant women at term admitted to an East London maternity unit

Snapshot PCR surveillance for SARS-CoV-2 in hospital staff in England

SARS-CoV-2 infection, clinical features and outcome of COVID-19 in United Kingdom nursing homes

Presymptomatic SARS-CoV-2 Infections and Transmission in a Skilled Nursing Facility

SARS-CoV-2 screening of asymptomatic healthcare workers

Screening for SARS-CoV-2 Infection Within a Psychiatric Hospital and Considerations for Limiting Transmission Within Residential Psychiatric Facilities -Wyoming, 2020. MMWR Morb Mortal Wkly Rep

Lessons from Mass-Testing for COVID-19 in Long Term Care Facilities for the Elderly in San Francisco

Spread of SARS-CoV-2 in the Icelandic Population

Mass testing for asymptomatic COVID-19 infection among health care workers at a large Canadian Hospital

Official Journal of the Association of Medical Microbiology and Infectious Disease Canada

Suppression of a SARS-CoV-2 outbreak in the Italian municipality of Vo

Asymptomatic and Presymptomatic SARS-CoV-2 Infections in Residents of a Long-Term Care Skilled Nursing Facility

Search for asymptomatic carriers of SARS-CoV-2 in healthcare workers during the pandemic: a Spanish experience

Limited effectiveness of systematic screening by nasopharyngeal RT-PCR of medicalized nursing home staff after a first case of COVID-19 in a resident

Medecine et Maladies Infectieuses

Detection of SARS-CoV-2 Among Residents and Staff Members of an Independent and Assisted Living Community for Older Adults

High prevalence of SARS-CoV-2 infection in repatriation flights to Greece from three European countries

Evidence of SARS-CoV-2 Infection in Returning Travelers from Wuhan, China

Post-lockdown SARS-CoV-2 nucleic acid screening in nearly ten million residents of Wuhan, China

Prevalence of SARS-CoV-2 Infection in Residents of a Large Homeless Shelter in Boston

Coronavirus Disease 2019 (COVID-19) Outbreak in a San Francisco Homeless Shelter

Risk of bias tools in systematic reviews of health interventions: an analysis of PROSPERO-registered protocols

Cochrane Handbook for Systematic Reviews of Interventions version 6

In defence of digital contact-tracing: human rights, South Korea and Covid-19

A Framework for Sustainable Contact Tracing and Exposure Investigation for Large Health Systems

Digital contact tracing technologies in epidemics: A rapid review. Cochrane Database Syst Rev

Mass testing for covid-19 in the UK

The BMJ

Acceptability of App-Based Contact Tracing for COVID-19: Cross-Country Survey Study

Meta-analyses and Forest plots using a microsoft excel spreadsheet: Step-by-step guide focusing on descriptive data analysis

Covid-19 mass testing facilities could end the epidemic rapidly

The BMJ

Why Mandatory Mass Testing for COVID-19 is a Poor Policy

Universal screening for SARS-CoV-2 infection: a rapid review

Cochrane Database of Systematic Reviews

Estimating the extent of asymptomatic COVID-19 and its potential for community transmission: Systematic review and meta-analysis

European Centre for Disease Prevention and Control. COVID-19 testing strategies and objectives

Prevalence of Asymptomatic SARS-CoV-2 Infection : A Narrative Review

High Prevalence of Asymptomatic COVID-19 Infection in Hemodialysis Patients Detected Using Serologic Screening

High prevalence of asymptomatic COVID-19 in hemodialysis. Daily learning during first month of COVID-19 pandemic

The prevalence of asymptomatic and symptomatic COVID-19 in a cohort of quarantined subjects

Proportion of asymptomatic infection among COVID-19 positive persons and their transmission potential: A systematic review and meta-analysis

Asymptomatic and Pre-Symptomatic COVID-19 in China

Infectious Diseases of Poverty

A Rapid Review of the Asymptomatic Proportion of PCR-Confirmed SARS-CoV-2 Infections in Community Settings

<p>Three Quarters of People with SARS-CoV-2 Infection are Asymptomatic: Analysis of English Household Survey Data</p>

Early lessons from a second COVID-19 lockdown in Leicester

Journal of Cleaner Production

Impact of lockdown on COVID-19 epidemic in Île-de-France and possible exit strategies

Train and deploy a community level public health workforce to combat covid-19

NLM (Medline)

Lessons in contact tracing from Germany: Germany built on existing local infrastructure to get ahead of the covid-19 pandemic

The BMJ

Pooled Testing for Expanding COVID-19 Mass Surveillance

Tracing asymptomatic SARS-CoV-2 carriers among 3674 hospital staff:a cross-sectional survey

Effectiveness of airport screening at detecting travellers infected with novel coronavirus (2019-nCoV)

European Centre for Disease Prevention and Control (ECDC)

Estimated effectiveness of symptom and risk screening to prevent the spread of COVID-19

Lesbos: Hundreds test positive for Covid-19 after migrant camp fire

COVID-19 in the Rohingya refugee camps of Bangladesh: challenges and mitigation strategies

Effectiveness of isolation, testing, contact tracing, and physical distancing on reducing transmission of SARS-CoV-2 in different settings: a mathematical modelling study

Screening Testing for SARS-CoV-2 upon Admission to Rehabilitation Hospitals in a High COVID-19 Prevalence Community

Using a real-world network to model localized COVID-19 control strategies

Efficacy of contact tracing for the containment of the 2019 novel coronavirus (COVID-19)

Modeling Contact Tracing Strategies for COVID-19 in the Context of Relaxed Physical Distancing Measures

Impact of delays on effectiveness of contact tracing strategies for COVID-19: a modelling study

COVID-19 testing and infection surveillance: Is a combined digital contact-tracing and mass-testing solution feasible in the United States? Cardiovasc Digit Heal J

Controlling COVID-19 via test-trace-quarantine Cliff

Determining the optimal strategy for reopening schools, the impact of test and trace interventions, and the risk of occurrence of a second COVID-19 epidemic wave in the UK: a modelling study

Feasibility of controlling COVID-19 outbreaks by isolation of cases and contacts

Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing

Estimating the Effectiveness of Non-Pharmaceutical Interventions on COVID-19 Control in Korea

Technical Document 3: Effectiveness and Resource Requirements of Test, Trace and Isolate Strategies

Modelling SARS-COV2 Spread in London: Approaches to Lift the Lockdown

Perfect as the Enemy of the Good: Using Low-Sensitivity Tests to Mitigate SARS-CoV-2 Outbreaks

Weekly COVID-19 testing with household quarantine and contact tracing is feasible and would probably end the epidemic. R Soc Open Sci

Active testing of groups at increased risk of acquiring SARS-CoV-2 in Canada: Costs and human resource needs

A workable strategy for COVID-19 testing: stratified periodic testing rather than universal random testing

Mass screening of asymptomatic persons for SARS-CoV-2 using saliva

Cost -benefit of limited isolation and testing in COVID -19 mitigation

Saliva specimens for detection of severe acute respiratory syndrome coronavirus 2 in Kuwait: A cross-sectional study

Risk Assessment and Management of COVID-19 Among Travelers Arriving at Designated U.S. Airports

Morbidity and Mortality Weekly Report Preventing COVID-19 Outbreaks in Long-Term Care Facilities Through Preemptive Testing of Residents and Staff Members-Fulton County

Impact of mass testing during an epidemic rebound of SARS-CoV-2: A modelling study

Asymptomatic SARS-CoV-2 carriers among detected cases, asymptomatic and mixed sample populations. The overall outcome is contributed by the first 2 sections from below Asymp Pop: Asymptomatic population

Abeysuriya(2020) Guery

) Nishiura(2020) Brown

Positive Cases Louie

) Lytras(2020)(Spain) Lytras(2020)(Turkey) Treibel

) Lytras(2020)(UK) Hoehl