scholarly journals Evaluation of Contact-Tracing Policies against the Spread of SARS-CoV-2 in Austria: An Agent-Based Simulation

2021 ◽  
pp. 0272989X2110133
Author(s):  
Martin Bicher ◽  
Claire Rippinger ◽  
Christoph Urach ◽  
Dominik Brunmeir ◽  
Uwe Siebert ◽  
...  
Keyword(s):  
Contact Tracing ◽  
High Price ◽  
Parameter Estimates ◽  
Agent Based ◽  
Secondary Infections ◽  
Efficient Measure ◽  
Containment Policy ◽  
Restrictive Measures ◽  
The Impact

Background Many countries have already gone through several infection waves and mostly managed to successfully stop the exponential spread of SARS-CoV-2 through bundles of restrictive measures. Still, the danger of further waves of infections is omnipresent, and it is apparent that every containment policy must be carefully evaluated and possibly replaced by a different, less restrictive policy before it can be lifted. Tracing of contacts and consequential breaking of infection chains is a promising strategy to help contain the disease, although its precise impact on the epidemic is unknown. Objective In this work, we aim to quantify the impact of tracing on the containment of the disease and investigate the dynamic effects involved. Design We developed an agent-based model that validly depicts the spread of the disease and allows for exploratory analysis of containment policies. We applied this model to quantify the impact of different approaches of contact tracing in Austria to derive general conclusions on contract tracing. Results The study displays that strict tracing complements other intervention strategies. For the containment of the disease, the number of secondary infections must be reduced by about 75%. Implementing the proposed tracing strategy supplements measures worth about 5%. Evaluation of the number of preventively quarantined persons shows that household quarantine is the most effective in terms of avoided cases per quarantined person. Limitations The results are limited by the validity of the modeling assumptions, model parameter estimates, and the quality of the parametrization data. Conclusions The study shows that tracing is indeed an efficient measure to keep case numbers low but comes at a high price if the disease is not well contained. Therefore, contact tracing must be executed strictly, and adherence within the population must be held up to prevent uncontrolled outbreaks of the disease.

scholarly journals Exploring the effectiveness of a COVID-19 contact tracing app using an agent-based model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jonatan Almagor ◽  
Stefano Picascia
Keyword(s):  
High Rate ◽  
Contact Tracing ◽  
Agent Based Model ◽  
Agent Based ◽  
The Social ◽  
Behavioural Factors ◽  
The Impact ◽  
Different Levels ◽  
User Rate

AbstractA contact-tracing strategy has been deemed necessary to contain the spread of COVID-19 following the relaxation of lockdown measures. Using an agent-based model, we explore one of the technology-based strategies proposed, a contact-tracing smartphone app. The model simulates the spread of COVID-19 in a population of agents on an urban scale. Agents are heterogeneous in their characteristics and are linked in a multi-layered network representing the social structure—including households, friendships, employment and schools. We explore the interplay of various adoption rates of the contact-tracing app, different levels of testing capacity, and behavioural factors to assess the impact on the epidemic. Results suggest that a contact tracing app can contribute substantially to reducing infection rates in the population when accompanied by a sufficient testing capacity or when the testing policy prioritises symptomatic cases. As user rate increases, prevalence of infection decreases. With that, when symptomatic cases are not prioritised for testing, a high rate of app users can generate an extensive increase in the demand for testing, which, if not met with adequate supply, may render the app counterproductive. This points to the crucial role of an efficient testing policy and the necessity to upscale testing capacity.

scholarly journals Investigations of agent-based modelling for inpatient healthcare systems

2021 ◽  
Author(s):  
Amirkiarash Kiani
Keyword(s):  
Quality Of Care ◽  
Recovery Time ◽  
Well Being ◽  
Patient Acuity ◽  
Agent Based ◽  
Agent Based Modelling ◽  
Novel Approach ◽  
Research Plan ◽  
The Impact

The goal of this research was to investigate the possibility of using Agent-based Modelling, a novel approach in computerized simulation, to assess the effects of staff ratio on recovery time and to develop an empirical research plan based on an inpatient unit. By creating a virtual unit, the researcher was able to develop an adjustable model to test several scenarios based on empirical evidence; to comprehend the impact of changes to staff ratio and patient acuity on nurses’ workload and quality of care to patients. This investigation found that acuity indices of patients have no significant effect on available recovery time or the number of unperformed activities. On the contrary, nurse/patient ratio has substantial effects on both available recovery time and the number of unperformed activities; which asserts the significant effect of insufficient nurse staffing on the well-being of nurses as well as quality of care to patients.

scholarly journals Estimating the impact of interventions against COVID-19: from lockdown to vaccination

2021 ◽  
Author(s):  
James Thompson ◽  
Stephen Wattam
Keyword(s):  
Spatial Clustering ◽  
Herd Immunity ◽  
Contact Tracing ◽  
Agent Based Model ◽  
Seir Model ◽  
Agent Based ◽  
Resident Population ◽  
First Case ◽  
Equivalent Equation ◽  
The Impact

AbstractCoronavirus disease 2019 (COVID-19) is an infectious disease of humans caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the first case was identified in China in December 2019 the disease has spread worldwide, leading to an ongoing pandemic. In this article, we present a detailed agent-based model of COVID-19 in Luxembourg, and use it to estimate the impact, on cases and deaths, of interventions including testing, contact tracing, lockdown, curfew and vaccination.Our model is based on collation, with agents performing activities and moving between locations accordingly. The model is highly heterogeneous, featuring spatial clustering, over 2000 behavioural types and a 10 minute time resolution. The model is validated against COVID-19 clinical monitoring data collected in Luxembourg in 2020.Our model predicts far fewer cases and deaths than the equivalent equation-based SEIR model. In particular, with R0 = 2.45, the SEIR model infects 87% of the resident population while our agent-based model results, on average, in only around 23% of the resident population infected. Our simulations suggest that testing and contract tracing reduce cases substantially, but are much less effective at reducing deaths. Lockdowns appear very effective although costly, while the impact of an 11pm-6am curfew is relatively small. When vaccinating against a future outbreak, our results suggest that herd immunity can be achieved at relatively low levels, with substantial levels of protection achieved with only 30% of the population immune. When vaccinating in midst of an outbreak, the challenge is more difficult. In this context, we investigate the impact of vaccine efficacy, capacity, hesitancy and strategy.We conclude that, short of a permanent lockdown, vaccination is by far the most effective way to suppress and ultimately control the spread of COVID-19.

scholarly journals Anatomy of digital contact tracing: role of age, transmission setting, adoption and case detection

2020 ◽  
Author(s):  
Jesús A. Moreno López ◽  
Beatriz Arregui-Garcĺa ◽  
Piotr Bentkowski ◽  
Livio Bioglio ◽  
Francesco Pinotti ◽  
...  
Keyword(s):  
Age Groups ◽  
Contact Tracing ◽  
Case Detection ◽  
Agent Based ◽  
Population Immunity ◽  
Contact Survey ◽  
Low Coverage ◽  
The Impact ◽  
Epidemiological Information

The efficacy of digital contact tracing against COVID-19 epidemic is debated: smartphone penetration is limited in many countries, non-uniform across age groups, with low coverage among elderly, the most vulnerable to SARS-CoV-2. We developed an agent-based model to precise the impact of digital contact tracing and household isolation on COVID-19 transmission. The model, calibrated on French population, integrates demographic, contact-survey and epidemiological information to describe the risk factors for exposure and transmission of COVID-19. We explored realistic levels of case detection, app adoption, population immunity and transmissibility. Assuming a reproductive ratio R=2.6 and 50% detection of clinical cases, a ~20% app adoption reduces peak incidence of ~36%. With R=1.7, >30% app adoption lowers the epidemic to manageable levels. Higher coverage among adults, playing a central role in COVID-19 transmission, yields an indirect benefit for elderly. These results may inform the inclusion of digital contact tracing within a COVID-19 response plan.

Interventions to control nosocomial transmission of SARS-CoV-2: a modelling study

BMC Medicine ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Thi Mui Pham ◽  
Hannan Tahir ◽  
Janneke H. H. M. van de Wijgert ◽  
Bastiaan R. Van der Roest ◽  
Pauline Ellerbroek ◽  
...  
Keyword(s):  
Control Measures ◽  
Nosocomial Transmission ◽  
Sensitivity Analyses ◽  
Contact Tracing ◽  
Hospital Data ◽  
Agent Based ◽  
Effective Interventions ◽  
Maximum Test ◽  
Hospital Wards ◽  
The Impact

Abstract Background Emergence of more transmissible SARS-CoV-2 variants requires more efficient control measures to limit nosocomial transmission and maintain healthcare capacities during pandemic waves. Yet the relative importance of different strategies is unknown. Methods We developed an agent-based model and compared the impact of personal protective equipment (PPE), screening of healthcare workers (HCWs), contact tracing of symptomatic HCWs and restricting HCWs from working in multiple units (HCW cohorting) on nosocomial SARS-CoV-2 transmission. The model was fit on hospital data from the first wave in the Netherlands (February until August 2020) and assumed that HCWs used 90% effective PPE in COVID-19 wards and self-isolated at home for 7 days immediately upon symptom onset. Intervention effects on the effective reproduction number (RE), HCW absenteeism and the proportion of infected individuals among tested individuals (positivity rate) were estimated for a more transmissible variant. Results Introduction of a variant with 56% higher transmissibility increased — all other variables kept constant — RE from 0.4 to 0.65 (+ 63%) and nosocomial transmissions by 303%, mainly because of more transmissions caused by pre-symptomatic patients and HCWs. Compared to baseline, PPE use in all hospital wards (assuming 90% effectiveness) reduced RE by 85% and absenteeism by 57%. Screening HCWs every 3 days with perfect test sensitivity reduced RE by 67%, yielding a maximum test positivity rate of 5%. Screening HCWs every 3 or 7 days assuming time-varying test sensitivities reduced RE by 9% and 3%, respectively. Contact tracing reduced RE by at least 32% and achieved higher test positivity rates than screening interventions. HCW cohorting reduced RE by 5%. Sensitivity analyses show that our findings do not change significantly for 70% PPE effectiveness. For low PPE effectiveness of 50%, PPE use in all wards is less effective than screening every 3 days with perfect sensitivity but still more effective than all other interventions. Conclusions In response to the emergence of more transmissible SARS-CoV-2 variants, PPE use in all hospital wards might still be most effective in preventing nosocomial transmission. Regular screening and contact tracing of HCWs are also effective interventions but critically depend on the sensitivity of the diagnostic test used.

scholarly journals Depression during the COVID-19 pandemic (analysis of clinical cases)

2021 ◽  
Vol 13 (1) ◽  
pp. 81-86
Author(s):  
I. Yu. Dorozhenok
Keyword(s):  
Female Patient ◽  
Depressive Disorders ◽  
Therapy Regimen ◽  
History Of ◽  
Coronavirus Infection ◽  
Restrictive Measures ◽  
The Impact ◽  
Financial Losses ◽  
Clinical Cases

Currently, in various world regions, the prevalence of depressive and anxiety disorders due to the impact of coronavirus infection is repeatedly increased compared to that in previous years. Among the predictors of their development during the pandemic, there are COVID-19 symptoms, a history of mental disorders, as well as restrictive measures, and financial losses.The paper describes three clinical cases of depressive disorders during the COVID-19 pandemic, with the depiction of the anamnesis, somatic and mental status, the patholopsychogical qualification of the condition, and the justification of a therapy regimen. The multifactorial stressor effect of the COVID-19 pandemic has provoked an exacerbation of depression in a male patient with a history of affective disorder; the development of a nosogenic depressive reaction of demoralization in a female patient with coronavirus pneumonia; the worsening of somatization dysthymia in a female patient of involutional age. The timely recognition of depression and its treatment with currently available antidepressants have contributed to the achievement of high-quality remission, the increase of stress resistance, and the improvement of quality of life in the patients.

scholarly journals Estimating the impact of interventions against COVID-19: From lockdown to vaccination

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261330
Author(s):  
James Thompson ◽  
Stephen Wattam
Keyword(s):  
Spatial Clustering ◽  
Herd Immunity ◽  
Contact Tracing ◽  
Agent Based Model ◽  
Seir Model ◽  
Agent Based ◽  
Resident Population ◽  
First Case ◽  
Equivalent Equation ◽  
The Impact

Coronavirus disease 2019 (COVID-19) is an infectious disease of humans caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Since the first case was identified in China in December 2019 the disease has spread worldwide, leading to an ongoing pandemic. In this article, we present an agent-based model of COVID-19 in Luxembourg, and use it to estimate the impact, on cases and deaths, of interventions including testing, contact tracing, lockdown, curfew and vaccination. Our model is based on collation, with agents performing activities and moving between locations accordingly. The model is highly heterogeneous, featuring spatial clustering, over 2000 behavioural types and a 10 minute time resolution. The model is validated against COVID-19 clinical monitoring data collected in Luxembourg in 2020. Our model predicts far fewer cases and deaths than the equivalent equation-based SEIR model. In particular, with R0 = 2.45, the SEIR model infects 87% of the resident population while our agent-based model infects only around 23% of the resident population. Our simulations suggest that testing and contract tracing reduce cases substantially, but are less effective at reducing deaths. Lockdowns are very effective although costly, while the impact of an 11pm-6am curfew is relatively small. When vaccinating against a future outbreak, our results suggest that herd immunity can be achieved at relatively low coverage, with substantial levels of protection achieved with only 30% of the population fully immune. When vaccinating in the midst of an outbreak, the challenge is more difficult. In this context, we investigate the impact of vaccine efficacy, capacity, hesitancy and strategy. We conclude that, short of a permanent lockdown, vaccination is by far the most effective way to suppress and ultimately control the spread of COVID-19.

scholarly journals Interventions to control nosocomial transmission of SARS-CoV-2: a modelling study

2021 ◽  
Author(s):  
Thi Mui Pham ◽  
Hannan Tahir ◽  
Janneke H.H.M. van de Wijgert ◽  
Bastiaan Van der Roest ◽  
Pauline Ellerbroek ◽  
...  
Keyword(s):  
Control Measures ◽  
Nosocomial Transmission ◽  
Sensitivity Analyses ◽  
Contact Tracing ◽  
Hospital Data ◽  
Agent Based ◽  
Effective Interventions ◽  
Maximum Test ◽  
Hospital Wards ◽  
The Impact

AbstractBackgroundEmergence of more transmissible SARS-CoV-2 variants requires more efficient control measures to limit nosocomial transmission and maintain healthcare capacities during pandemic waves. Yet, the relative importance of different strategies is unknown.MethodsWe developed an agent-based model and compared the impact of personal protective equipment (PPE), screening of healthcare workers (HCWs), contact tracing of symptomatic HCWs, and restricting HCWs from working in multiple units (HCW cohorting) on nosocomial SARS-CoV-2 transmission. The model was fit on hospital data from the first wave in the Netherlands (February until August 2020) and assumed that HCWs used 90% effective PPE in COVID-19 wards and self-isolated at home for seven days immediately upon symptom onset. Intervention effects on the effective reproduction number (RE), HCW absenteeism and the proportion of infected individuals among tested individuals (positivity rate) were estimated for a more transmissible variant.ResultsIntroduction of a variant with 56% higher transmissibility increased – all other variables kept constant – RE from 0.4 to 0.65 (+63%) and nosocomial transmissions by 303%, mainly because of more transmissions caused by pre-symptomatic patients and HCWs. Compared to baseline, PPE use in all hospital wards (assuming 90% effectiveness) reduced RE by 85% and absenteeism by 57%. Screening HCWs every three days with perfect test sensitivity reduced RE by 67%, yielding a maximum test positivity rate of 5%. Screening HCWs every three or seven days assuming time-varying test sensitivities reduced RE by 9% and 3%, respectively. Contact tracing reduced RE by at least 32% and achieved higher test positivity rates than screening interventions. HCW cohorting reduced RE by 5%. Sensitivity analyses for 50% and 70% effectiveness of PPE use did not change interpretation.ConclusionsIn response to the emergence of more transmissible SARS-CoV-2 variants, PPE use in all hospital wards might still be most effective in preventing nosocomial transmission. Regular screening and contact tracing of HCWs are also effective interventions, but critically depend on the sensitivity of the diagnostic test used.

scholarly journals An imperfect tool: COVID-19 ‘test & trace’ success relies on minimising the impact of false negatives and continuation of physical distancing

2020 ◽  
Author(s):  
Emma L. Davis ◽  
Tim C. D. Lucas ◽  
Anna Borlase ◽  
Timothy M Pollington ◽  
Sam Abbot ◽  
...  
Keyword(s):  
Process Model ◽  
Diagnostic Testing ◽  
False Negative ◽  
Contact Tracing ◽  
Parameter Estimates ◽  
Sensitivity Testing ◽  
Test Sensitivity ◽  
Negative Results ◽  
The Impact

AbstractBackgroundFollowing a consistent decline in COVID-19-related deaths in the UK throughout May 2020, it is recognised that contact tracing will be vital to relaxing physical distancing measures. The increasingly evident role of asymptomatic and pre-symptomatic transmission means testing is central to control, but test sensitivity estimates are as low as 65%.MethodsWe extend an existing UK-focused branching process model for contact tracing, adding diagnostic testing and refining parameter estimates to demonstrate the impact of poor test sensitivity and suggest mitigation methods. We also investigate the role of super-spreading events, providing estimates of the relationship between infections, cases detected and hospitalisations, and consider how tracing coverage and speed affects outbreak risk.FindingsIncorporating poor sensitivity testing into tracing protocols could reduce efficacy, due to false negative results impacting isolation duration. However, a 7-day isolation period for all negative-testing individuals could mitigate this effect. Similarly, reducing delays to testing following exposure has a negligible impact on the risk of future outbreaks, but could undermine control if negative-testing individuals immediately cease isolating. Even 100% tracing of contacts will miss cases, which could prompt large localised outbreaks if physical distancing measures are relaxed prematurely.InterpretationIt is imperative that test results are interpreted with caution due to high false-negative rates and that contact tracing is used in combination with physical distancing measures. If the risks associated with imperfect test sensitivity are mitigated, we find that contact tracing can facilitate control when the reproduction number with physical distancing, RS, is less than 1·5.

scholarly journals The Quality of Medical Care in the Conditions of the COVID-19 Pandemic, with Particular Emphasis on the Access to Primary Healthcare and the Effectiveness of Treatment in Poland

2021 ◽  
Vol 10 (16) ◽  
pp. 3502
Author(s):  
Magdalena Kludacz-Alessandri ◽  
Renata Walczak ◽  
Liliana Hawrysz ◽  
Piotr Korneta
Keyword(s):  
Patient Satisfaction ◽  
Medical Care ◽  
Primary Healthcare ◽  
Treatment Effectiveness ◽  
Healthcare Services ◽  
Remote Healthcare ◽  
Considerable Impact ◽  
Restrictive Measures ◽  
The Impact

Health has a significant influence on the quality of life of a society. The COVID-19 pandemic has forced many countries to implement restrictive measures to prevent its wider spread, including, inter alia, the introduction of remote healthcare in the form of teleconsultations. Therefore, there is the question of how such a change affects the quality of treatment and the primary healthcare of patients during the COVID-19 pandemic. The article aims to examine patient satisfaction with the access to primary healthcare and the effectiveness of treatment in a condition of remote medical care caused by the COVID-19 pandemic. We also analyse the impact of access to primary healthcare on the treatment effectiveness. Patient satisfaction was measured using a questionnaire assessing the quality of primary medical care. Of the 36 items studied, seven were related to the accessibility dimension and four were related to the treatment effectiveness dimension. Our results suggest that the treatment effectiveness and the access to primary healthcare services during the COVID-19 pandemic through telemedicine are quite highly rated by patients. Hence, further implementation of telemedicine in primary healthcare should improve the quality of lives of the wide society. We have also identified the access to primary healthcare has a considerable impact on the treatment effectiveness. Therefore, we recommend increasing the contact between patients and GPs via telemedicine under lockdown conditions.

Sign in / Sign up

Export Citation Format

Share Document