scholarly journals Importance of untested infectious individuals for interventions to suppress COVID-19

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Francisco J. Pérez-Reche ◽  
Ken J. Forbes ◽  
Norval J. C. Strachan

AbstractThe impact of the extent of testing infectious individuals on suppression of COVID-19 is illustrated from the early stages of outbreaks in Germany, the Hubei province of China, Italy, Spain and the UK. The predicted percentage of untested infected individuals depends on the specific outbreak but we found that they typically represent 60–80% of all infected individuals during the early stages of the outbreaks. We propose that reducing the underlying transmission from untested cases is crucial to suppress the virus. This can be achieved through enhanced testing in combination with social distancing and other interventions that reduce transmission such as wearing face masks. Once transmission from silent carriers is kept under control by these means, the virus could have been fully suppressed through fast isolation and contact tracing of tested cases.

Author(s):  
Francisco J. Pérez-Reche ◽  
Ken J. Forbes ◽  
Norval J. C. Strachan

AbstractThe impact of the extent of testing infectious individuals on suppression of COVID-19 is illustrated from the early stages of outbreaks in Germany, the Hubei province of China, Italy, Spain and the UK. The predicted percentage of untested infected individuals depends on the specific outbreak but we found that they typically represent 50% to 80% of the infected individuals. Even when unreported cases are taken into account, we estimate that less than 8% of the population would have been exposed to SARS-CoV-2 by 09/04/2020 in the analysed outbreaks. These levels are far below the 70-85% needed to ensure herd immunity and would predict a resurgence of infection if ongoing lockdowns in the outbreaks are fully lifted. We propose that partially lifted lockdowns together with early and thorough testing allowing for quick isolation of both symptomatic and asymptomatic cases could lead to suppression of secondary waves of COVID-19 epidemics.


2020 ◽  
Author(s):  
Jasmina Panovska-Griffiths ◽  
Cliff Kerr ◽  
Robyn Margaret Stuart ◽  
Dina Mistry ◽  
Daniel Klein ◽  
...  

Background In order to slow down the spread of SARS-CoV-2, the virus causing the COVID-19 pandemic, the UK government has imposed strict physical distancing (lockdown) measures including school 'dismissals' since 23 March 2020. As evidence is emerging that these measures may have slowed the spread of the pandemic, it is important to assess the impact of any changes in strategy, including scenarios for school reopening and broader relaxation of social distancing. This work uses an individual-based model to predict the impact of a suite of possible strategies to reopen schools in the UK, including that currently proposed by the UK government. Methods We use Covasim, a stochastic agent-based model for transmission of COVID-19, calibrated to the UK epidemic. The model describes individuals' contact networks stratified as household, school, work and community layers, and uses demographic and epidemiological data from the UK. We simulate a range of different school reopening strategies with a society-wide relaxation of lockdown measures and in the presence of different non-pharmaceutical interventions, to estimate the number of new infections, cumulative cases and deaths, as well as the effective reproduction number with different strategies. To account for uncertainties within the stochastic simulation, we also simulated different levels of infectiousness of children and young adults under 20 years old compared to older ages. Findings We found that with increased levels of testing of people (between 25% and 72% of symptomatic people tested at some point during an active COVID-19 infection depending on scenarios) and effective contact-tracing and isolation for infected individuals, an epidemic rebound may be prevented across all reopening scenarios, with the effective reproduction number (R) remaining below one and the cumulative number of new infections and deaths significantly lower than they would be if testing did not increase. If UK schools reopen in phases from June 2020, prevention of a second wave would require testing 51% of symptomatic infections, tracing of 40% of their contacts, and isolation of symptomatic and diagnosed cases. However, without such measures, reopening of schools together with gradual relaxing of the lockdown measures are likely to induce a secondary pandemic wave, as are other scenarios for reopening. When infectiousness of <20 year olds was varied from 100% to 50% of that of older ages, our findings remained unchanged. Interpretation To prevent a secondary COVID-19 wave, relaxation of social distancing including reopening schools in the UK must be implemented alongside an active large-scale population-wide testing of symptomatic individuals and effective tracing of their contacts, followed by isolation of symptomatic and diagnosed individuals. Such combined measures have a greater likelihood of controlling the transmission of SARS-CoV-2 and preventing a large number of COVID-19 deaths than reopening schools and society with the current level of implementation of testing and isolation of infected individuals.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Harry E. R. Shepherd ◽  
Florence S. Atherden ◽  
Ho Man Theophilus Chan ◽  
Alexandra Loveridge ◽  
Andrew J. Tatem

Abstract Background Since early March 2020, the COVID-19 epidemic across the United Kingdom has led to a range of social distancing policies, which resulted in changes to mobility across different regions. An understanding of how these policies impacted travel patterns over time and at different spatial scales is important for designing effective strategies, future pandemic planning and in providing broader insights on the population geography of the country. Crowd level data on mobile phone usage can be used as a proxy for population mobility patterns and provide a way of quantifying in near-real time the impact of social distancing measures on changes in mobility. Methods Here we explore patterns of change in densities, domestic and international flows and co-location of Facebook users in the UK from March 2020 to March 2021. Results We find substantial heterogeneities across time and region, with large changes observed compared to pre-pademic patterns. The impacts of periods of lockdown on distances travelled and flow volumes are evident, with each showing variations, but some significant reductions in co-location rates. Clear differences in multiple metrics of mobility are seen in central London compared to the rest of the UK, with each of Scotland, Wales and Northern Ireland showing significant deviations from England at times. Moreover, the impacts of rapid changes in rules on international travel to and from the UK are seen in substantial fluctuations in traveller volumes by destination. Conclusions While questions remain about the representativeness of the Facebook data, previous studies have shown strong correspondence with census-based data and alternative mobility measures, suggesting that findings here are valuable for guiding strategies.


2021 ◽  
Author(s):  
Aimee Code ◽  
Umar Toseeb ◽  
Kathryn Asbury ◽  
Laura Fox

Due to the COVID-19 pandemic and resultant school closures, social distancing measures, and restrictions placed on routine activities, the start of the academic year in September 2020 was a unique time for those transitioning to a new school. This study aimed to explore the experiences of parents who supported autistic children making a school transition in 2020, and to examine what impact parents perceived the COVID-19 pandemic had on their child’s school transition. Emphasis was placed on identifying facilitating factors that had benefitted school transitions, and barriers, which had negatively impacted these experiences. Semi-structured interviews were carried out with 13 parents of autistic children in the UK. Reflexive thematic analysis was carried out to identify themes in interview data. Parents reported a variety of experiences, and factors that were perceived as facilitatory to some were observed to be barriers by others. For some parents, the COVID-19 pandemic negatively impacted aspects of school transitions. For example, school closure in March 2020, being unable to visit their child’s new school, and social distancing measures were discussed as being barriers to an easy transition. However, other parents identified these factors as being facilitatory for their child or reported that these circumstances created opportunities to approach the school transition in a unique, improved manner. This paper sheds light on the heterogeneity of experiences and perceptions of parents of autistic children, and highlights the need to examine the impact of COVID-19 on school transitions, including practices which may be advantageous to retain.


Science ◽  
2020 ◽  
Vol 368 (6498) ◽  
pp. 1481-1486 ◽  
Author(s):  
Juanjuan Zhang ◽  
Maria Litvinova ◽  
Yuxia Liang ◽  
Yan Wang ◽  
Wei Wang ◽  
...  

Intense nonpharmaceutical interventions were put in place in China to stop transmission of the novel coronavirus disease 2019 (COVID-19). As transmission intensifies in other countries, the interplay between age, contact patterns, social distancing, susceptibility to infection, and COVID-19 dynamics remains unclear. To answer these questions, we analyze contact survey data for Wuhan and Shanghai before and during the outbreak and contact-tracing information from Hunan province. Daily contacts were reduced seven- to eightfold during the COVID-19 social distancing period, with most interactions restricted to the household. We find that children 0 to 14 years of age are less susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection than adults 15 to 64 years of age (odds ratio 0.34, 95% confidence interval 0.24 to 0.49), whereas individuals more than 65 years of age are more susceptible to infection (odds ratio 1.47, 95% confidence interval 1.12 to 1.92). Based on these data, we built a transmission model to study the impact of social distancing and school closure on transmission. We find that social distancing alone, as implemented in China during the outbreak, is sufficient to control COVID-19. Although proactive school closures cannot interrupt transmission on their own, they can reduce peak incidence by 40 to 60% and delay the epidemic.


2020 ◽  
Vol 1 (1) ◽  
pp. 15-25
Author(s):  
Amod K. Pokhrel ◽  
Yadav P. Joshi ◽  
Sopnil Bhattarai

There is limited information on the epidemiology and the effects of mitigation measures on the spread of COVID-19 in Nepal. Using publicly available databases, we analyzed the epidemiological trend, the people's movement trends at different intervals across different categories of places and evaluated implications of social mobility on COVID-19. We also estimated the epidemic peak. As of June 9, 2020, Provinces 2 and 5 have most of the cases. People between 15 and 54 years are vulnerable to becoming infected, and more males than females are affected. The cases are growing exponentially. The growth rate of 0.13 and >1 reproduction numbers (R0) over time (median: 1.48; minimum: 0.58, and maximum: 3.71) confirms this trend. The case doubling time is five days. Google's community mobility data suggest that people strictly followed social distancing measures for one month after the lockdown. By around the 4th week of April, the individual's movement started rising, and social contacts increased. The number of cases peaked on May 12, with 83 confirmed cases in one day. The Susceptible-Exposed-Infectious-Removed (SEIR) model suggests that the epidemic will peak approximately on day 41 (July 21, 2020), and start to plateau after day 80. To contain the spread of the virus, people should maintain social distancing. The Government needs to continue active surveillance, more PCR-based testing, case detection, contact tracing, isolation, and quarantine. The Government should also provide financial support and safety-nets to the citizen to limit the impact of COVID-19.


Author(s):  
Geraldine Ann Akerman ◽  
Emily Jones ◽  
Harry Talbot ◽  
Gemma Grahame-Wright

Purpose This paper aims to describe the impact of the COVID-19 pandemic on a prison-based therapeutic community (TC). Design/methodology/approach The paper takes the form of a case study where the authors reflect on their current practice, using the findings of research on social isolation and the overarching TC principles to explore the effect of the pandemic on the TC at HMP Grendon. The authors consider how the residents and staff adjusted to the change as the parameters changed when the social distancing rules were imposed and how they adapted to the prolonged break to therapy. Sections in the paper were written by a resident and an operational member of staff. The authors conclude with their thoughts on how to manage the consequences the lockdown has brought and start to think about what returning to “normality” might mean. Findings The paper describes the adjustments made by the residents and staff as the UK Government imposed the lockdown. The authors, including a resident and an operational member of staff comment on the psychological and practical impact these adjustments had. The thought is given to the idea of “recovery”, returning to “normality” and how this study can be best managed once restrictions are lifted. Research limitations/implications At the time of writing, there are no confirmed cases of COVID-19 at HMP Grendon. The measures and commitment from all staff and residents in the prison to keep the prison environment safe may in part account for this. This paper explores the effects of lockdown on the emotional environment in a TC and highlights the consequences that social isolation can have on any individual. To the authors’ knowledge, there is currently no research undertaken on the impact of lockdown/social isolation on a TC. This research would be useful, as the authors postulate from reflections on current practice that the effects of the lockdown will be greater in a social therapy environment. Originality/value HMP Grendon started in 1962, as this time there have been no significant events that have meant the suspension of therapy for such a sustained period. It is, therefore, important that the impact of such is considered and reflected upon.


2020 ◽  
Vol 22 (6) ◽  
pp. 415-427
Author(s):  
Ann Anka ◽  
Helen Thacker ◽  
Bridget Penhale

Purpose This exploratory paper aims to examine the literature on the impact of COVID-19 on safeguarding adults practice. Design/methodology/approach A literature search was carried out in recently published articles to locate literature relating to COVID-19 and safeguarding adults in the UK and internationally. This included policy guidance and law, to describe the existing knowledge base, gaps in practice and areas that may require further research. Findings The findings suggest that measures to curb the spread of the COVID-19 pandemic gave rise to remote working and virtual safeguarding practice. The findings highlight the need for empirical research into the impact of virtual safeguarding adults assessments and effective ways to support the needs and outcomes of those who may be at risk of or experiencing abuse and neglect while shielding, socially isolating or when working in an environment where social distancing is required. Research limitations/implications The paper is based on a review and analysis of published documents and not on other types of research. Originality/value Little is known about effective safeguarding adults practice in the era of shielding, self-isolation, social distancing and remote working. The paper adds to the body of knowledge in the field.


2020 ◽  
pp. jech-2020-214051 ◽  
Author(s):  
Matt J Keeling ◽  
T Deirdre Hollingsworth ◽  
Jonathan M Read

ObjectiveContact tracing is a central public health response to infectious disease outbreaks, especially in the early stages of an outbreak when specific treatments are limited. Importation of novel coronavirus (COVID-19) from China and elsewhere into the UK highlights the need to understand the impact of contact tracing as a control measure.DesignDetailed survey information on social encounters from over 5800 respondents is coupled to predictive models of contact tracing and control. This is used to investigate the likely efficacy of contact tracing and the distribution of secondary cases that may go untraced.ResultsTaking recent estimates for COVID-19 transmission we predict that under effective contact tracing less than 1 in 6 cases will generate any subsequent untraced infections, although this comes at a high logistical burden with an average of 36 individuals traced per case. Changes to the definition of a close contact can reduce this burden, but with increased risk of untraced cases; we find that tracing using a contact definition requiring more than 4 hours of contact is unlikely to control spread.ConclusionsThe current contact tracing strategy within the UK is likely to identify a sufficient proportion of infected individuals such that subsequent spread could be prevented, although the ultimate success will depend on the rapid detection of cases and isolation of contacts. Given the burden of tracing a large number of contacts to find new cases, there is the potential the system could be overwhelmed if imports of infection occur at a rapid rate.


2020 ◽  
Vol 5 (9) ◽  
pp. e003055
Author(s):  
Amir Siraj ◽  
Alemayehu Worku ◽  
Kiros Berhane ◽  
Maru Aregawi ◽  
Munir Eshetu ◽  
...  

IntroductionSince its emergence in late December 2019, COVID-19 has rapidly developed into a pandemic in mid of March with many countries suffering heavy human loss and declaring emergency conditions to contain its spread. The impact of the disease, while it has been relatively low in the sub-Saharan Africa (SSA) as of May 2020, is feared to be potentially devastating given the less developed and fragmented healthcare system in the continent. In addition, most emergency measures practised may not be effective due to their limited affordability as well as the communal way people in SSA live in relative isolation in clusters of large as well as smaller population centres.MethodsTo address the acute need for estimates of the potential impacts of the disease once it sweeps through the African region, we developed a process-based model with key parameters obtained from recent studies, taking local context into consideration. We further used the model to estimate the number of infections within a year of sustained local transmissions under scenarios that cover different population sizes, urban status, effectiveness and coverage of social distancing, contact tracing and usage of cloth face mask.ResultsWe showed that when implemented early, 50% coverage of contact tracing and face mask, with 33% effective social distancing policies can bringing the epidemic to a manageable level for all population sizes and settings we assessed. Relaxing of social distancing in urban settings from 33% to 25% could be matched by introduction and maintenance of face mask use at 43%.ConclusionsIn SSA countries with limited healthcare workforce, hospital resources and intensive care units, a robust system of social distancing, contact tracing and face mask use could yield in outcomes that prevent several millions of infections and thousands of deaths across the continent.


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