scholarly journals On the Effectiveness of Digital Contact Tracing and Contact Prevention Under Varying COVID-19 Infection Detection Rates

2020 ◽  
Author(s):  
German Soldano ◽  
Juan A. Fraire ◽  
Jorge M. Finochietto ◽  
Rodrigo Quiroga
Keyword(s):  
Contact Tracing ◽  
Detection Rates ◽  
Infection Detection

scholarly journals On the Effectiveness of Digital Contact Tracing and Contact Prevention Under Varying COVID-19 Infection Detection Rates

2021 ◽  
Author(s):  
German José Soldano ◽  
Juan Andrés Fraire ◽  
Jorge Manuel Finochietto ◽  
Rodrigo Quiroga
Keyword(s):  
Response Time ◽  
Time Delays ◽  
Data Privacy ◽  
Developed Countries ◽  
Contact Tracing ◽  
Detection Rates ◽  
Agent Based ◽  
Infection Detection ◽  
Available Technology ◽  
Novel Strategy

Abstract A plethora of measures are being combined in the attempt to reduce SARS-CoV-2 spread. Due to its sustainability over time, contact tracing is one of the most frequently applied interventions worldwide, albeit with mixed results. In this work, we evaluate the perfomance of contact tracing for different infection detection rates and response time delays. We also introduce and analyze a novel strategy we call contact prevention. We model the effect of both strategies on contagion dynamics in SERIA, an agent-based simulation platform that implements realistic population-dependent statistical distributions. Results show that diagnostic/response time delays and low infection detection rates greatly impair the effect of contact tracing strategies, while contact prevention remains effective in these scenarios. Therefore, contact prevention could play a significant role in pandemic mitigation, specially in under-developed countries where diagnostic and tracing capabilities are insufficient. Contact prevention could thus sustainably reduce the propagation of respiratory viruses while relying on available technology, respecting data privacy, and most importantly, promoting community-based awareness and social responsibility. Depending on infection detection and app adoption rates, applying a combination of contact tracing and contact prevention could reduce pandemic-related mortality by 20%-56%.

scholarly journals COVID-19 mitigation by digital contact tracing and contact prevention (app-based social exposure warnings)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Germán J. Soldano ◽  
Juan A. Fraire ◽  
Jorge M. Finochietto ◽  
Rodrigo Quiroga
Keyword(s):  
Response Time ◽  
Time Delays ◽  
Data Privacy ◽  
Contact Tracing ◽  
Detection Rates ◽  
High Exposure ◽  
Infection Detection ◽  
Available Technology ◽  
Novel Strategy ◽  
Social Exposure

AbstractA plethora of measures are being combined in the attempt to reduce SARS-CoV-2 spread. Due to its sustainability, contact tracing is one of the most frequently applied interventions worldwide, albeit with mixed results. We evaluate the performance of digital contact tracing for different infection detection rates and response time delays. We also introduce and analyze a novel strategy we call contact prevention, which emits high exposure warnings to smartphone users according to Bluetooth-based contact counting. We model the effect of both strategies on transmission dynamics in SERIA, an agent-based simulation platform that implements population-dependent statistical distributions. Results show that contact prevention remains effective in scenarios with high diagnostic/response time delays and low infection detection rates, which greatly impair the effect of traditional contact tracing strategies. Contact prevention could play a significant role in pandemic mitigation, especially in developing countries where diagnostic and tracing capabilities are inadequate. Contact prevention could thus sustainably reduce the propagation of respiratory viruses while relying on available technology, respecting data privacy, and most importantly, promoting community-based awareness and social responsibility. Depending on infection detection and app adoption rates, applying a combination of digital contact tracing and contact prevention could reduce pandemic-related mortality by 20–56%.

scholarly journals Active case detection methods for crusted scabies and leprosy: A systematic review

2021 ◽  
Vol 15 (7) ◽  
pp. e0009577
Author(s):  
Miriam Glennie ◽  
Karen Gardner ◽  
Michelle Dowden ◽  
Bart J. Currie
Keyword(s):  
Systematic Review ◽  
Disease Control ◽  
Detection Methods ◽  
Contact Tracing ◽  
Case Detection ◽  
Community Screening ◽  
Detection Rates ◽  
Active Case Detection ◽  
Active Case ◽  
Crusted Scabies

Background Crusted scabies is endemic in some remote Aboriginal communities in the Northern Territory (NT) of Australia and carries a high mortality risk. Improvement in active case detection (ACD) for crusted scabies is hampered by a lack of evidence about best practice. We therefore conducted a systematic review of ACD methods for leprosy, a condition with similar ACD requirements, to consider how findings could be informative to crusted scabies detection. Methods and principle findings We conducted systematic searches in MEDLINE, CINAHL, Scopus and the Cochrane Database for Systematic Reviews for studies published since 1999 that reported at least one comparison rate (detection or prevalence rate) against which the yield of the ACD method could be assessed. The search yielded 15 eligible studies from 511. Study heterogeneity precluded meta-analysis. Contact tracing and community screening of marginalised ethnic groups yielded the highest new case detection rates. Rapid community screening campaigns, and those using less experienced screening personnel, were associated with lower suspect confirmation rates. There is insufficient data to assess whether ACD campaigns improve treatment outcomes or disease control. Conclusion This review demonstrates the importance of ACD campaigns in communities facing the highest barriers to healthcare access and within neighbourhoods of index cases. The potential benefit of ACD for crusted scabies is not quantified, however, lessons from leprosy suggest value in follow-up with previously identified cases and their close contacts to support for scabies control and to reduce the likelihood of reinfection in the crusted scabies case. Skilled screening personnel and appropriate community engagement strategies are needed to maximise screening uptake. More research is needed to assess ACD cost effectiveness, impact on disease control, and to explore ACD methods capable of capturing the homeless and highly mobile who may be missed in household centric models.

scholarly journals Leprosy Post-Exposure Prophylaxis (LPEP) programme: study protocol for evaluating the feasibility and impact on case detection rates of contact tracing and single dose rifampicin

BMJ Open ◽  
2016 ◽  
Vol 6 (11) ◽  
pp. e013633 ◽  
Author(s):  
Tanja Barth-Jaeggi ◽  
Peter Steinmann ◽  
Liesbeth Mieras ◽  
Wim van Brakel ◽  
Jan Hendrik Richardus ◽  
...  
Keyword(s):  
Single Dose ◽  
Study Protocol ◽  
Contact Tracing ◽  
Post Exposure Prophylaxis ◽  
Case Detection ◽  
Detection Rates ◽  
Post Exposure ◽  
Exposure Prophylaxis

scholarly journals Estimating the effectiveness of non-pharmaceutical interventions on COVID-19 control in South Korea

2020 ◽  
Author(s):  
Kyung-Duk Min ◽  
Heewon Kang ◽  
Ju-Yeun Lee ◽  
Seonghee Jeon ◽  
Sung-il Cho
Keyword(s):  
South Korea ◽  
Compartment Model ◽  
Contact Tracing ◽  
Contact Rate ◽  
Global Public Health ◽  
Spring Semester ◽  
Detection Rates ◽  
Social Distancing ◽  
Effective Contact ◽  
Pharmaceutical Interventions

Abstract Background: The coronavirus disease 2019 (COVID-19) pandemic has posed significant global public health challenges and created a substantial economic burden. South Korea has experienced an extensive outbreak, which was linked to a religion-related super-spreading event. However, the implementation of various non-pharmaceutical interventions (NPIs), including social distancing, spring semester postponing, and extensive testing and contact tracing controlled the epidemic. Herein, we estimated the effectiveness of each NPI using a simulation model.Methods: A compartment model with a susceptible-exposed-infectious-quarantined-hospitalized (SEIQH) structure was employed. Using the Monte-Carlo-Markov-Chain algorithm with Gibbs’ sampling method, we estimated the time-varying effective contact rate to calibrate the model with the reported daily new confirmed cases from February 12th to March 31st (7 weeks). Moreover, we conducted scenario analyses by adjusting the parameters to estimate the effectiveness of NPI.Results: Relaxed social distancing among adults would have increased the number of cases 27-fold until the end of March, and the epidemic curve would have been similar to other high burden countries. Spring semester non-postponement would have increased the effective contact rate 2·4-fold among individuals aged 0-19, while lower quarantine and detection rates would have increased the number of cases 1·4-fold. Conclusions: Among the three NPI measures, social distancing in adults showed the highest effectiveness. The substantial effect of social distancing should be considered for developing an exit strategy.

scholarly journals A novel comprehensive metric to assess COVID-19 testing outcomes: Effects of geography, government, and policy response

2020 ◽  
Author(s):  
Anthony C. Kuster ◽  
Hans J. Overgaard
Keyword(s):  
Detection Rate ◽  
Case Fatality ◽  
Multiple Linear Regression Model ◽  
System Capacity ◽  
Contact Tracing ◽  
Extrinsic Factors ◽  
Detection Rates ◽  
Case Identification ◽  
Rate Test ◽  
Reported Data

AbstractTesting and case identification are key strategies in controlling the COVID-19 pandemic. Contact tracing and isolation are only possible if cases have been identified. The effectiveness of testing must be tracked, but a single comprehensive metric is not available to assess testing effectiveness, and no timely estimates of case detection rate are available globally, making inter-country comparisons difficult. The purpose of this paper was to propose a single, comprehensive metric, called the COVID-19 Testing Index (CovTI) scaled from 0 to 100, that incorporated several testing metrics. The index was based on case-fatality rate, test positivity rate, active cases, and an estimate of the detection rate. It used parsimonious modeling to estimate the true total number of COVID-19 cases based on deaths, testing, health system capacity, and government transparency. Publicly reported data from 188 countries and territories were included in the index. Estimates of detection rates aligned with previous estimates in literature (R2=0.97). As of June 3, 2020, the states with the highest CovTI included Iceland, Australia, New Zealand, Hong Kong, and Thailand, and some island nations. Globally, CovTI increased from April 20 to June 3 but declined in ca. 10% of countries. Bivariate analyses showed the average in countries with open public testing policies (59.7, 95% CI 55.6-63.8) were significantly higher than countries with no testing policy (30.2, 95% CI 18.1-42.3) (p<0.0001). A multiple linear regression model assessed the association of independent grouping variables with CovTI. Open public testing and extensive contact tracing were shown to significantly increase CovTI, after adjusting for extrinsic factors, including geographic isolation and centralized forms of government. This tool may be useful for policymakers to assess testing effectiveness, inform decisions, and identify model countries. It may also serve as a tool for researchers in analyses by combining it with other databases.

scholarly journals Three decades History of Tuberculosis Control in Kerbala/Iraq

2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Ali Al Mousawi
Keyword(s):  
Treatment Failure ◽  
Detection Rate ◽  
Treatment Success ◽  
Contact Tracing ◽  
Case Detection ◽  
Failure Rates ◽  
Tuberculosis Control ◽  
Detection Rates ◽  
Case Detection Rate ◽  
Tuberculosis Patients

Objective: To assess tuberculosis control between 1988 and 2017 and evaluate the outcomes of treatment among the October patients put on DOTS in Karbala governorate since the initiation of DOTS strategy in 2000. Material and methods: Data on tuberculosis incidence between 1988 and 2017 were assessed. In addition, all quarterly reports were collected in addition to the annual reports to estimate the outcome indices of DOTS in the governorate. Evaluation indices included the incidence and death rates; case detection rate for smear positive and total tuberculosis patients; cure rate; treatment success rate; default rates; treatment failure rates; drug resistance rates; contact tracing during the study period between 2005 and 2014. These indices were compared to the available national indices in the whole country. The indices of treatment success and failure rates were compared to the available previous reported rates in the governorate and in Iraq. Analysis used SPSS-20 and Excel data sheet. Discussion with experts working for decades in TB control programs revealed some defect in determining these indices. Results: Between 1988 and 2017 there was a total of 8665 TB patients, while between 2005 and 2017 the total was 4055: 2592 pulmonary TB patients (62%) and 1541 extra-pulmonary tuberculosis patients (38%). Gender distribution showed male predilection (60.3%) and a mean age of patients was 41.88±19.74 year and one half of the patients were above 44 year of age, but the most frequent age group was 25-34 year. Positive smear Case Detection rates were below the WHO planned goals ranging from 11.5% and 29.1%. The total reported deaths during the study period were 78 deaths. Defaulters were 97 patients at a rate of 2.39, while treatment failure cases amounted to 33 patients (a rate of 0.81%). Drug sensitivity test was introduced to country in 2010 and was done only in Baghdad till the introduction of Genexpert MTB/RIF test in January 2014 and a total of 72 patients were MDR cases. Case detection rate among contacts was 0.31%. Conclusions: The success in DOTS in Karbala is similar to the results in the whole country and in most developing countries and approaching the WHO set goals, while the case detection rates were behind. However, some defect areas need further support to prevent failure and aid continuous tuberculosis control and stop TB.

scholarly journals Temporal trend of leprosy among the elderly in Brazil, 2001 – 2018

2020 ◽  
Vol 44 ◽  
pp. 1
Author(s):  
Margarida Cristiana Napoleão Rocha ◽  
Mauricio Lisboa Nobre ◽  
Leila Posenato Garcia
Keyword(s):  
Elderly People ◽  
Temporal Trends ◽  
Age Groups ◽  
The Elderly ◽  
Temporal Variations ◽  
Contact Tracing ◽  
Annual Percent Change ◽  
Detection Rates ◽  
Percent Change ◽  
Series Study

Objective. To describe the temporal trends of leprosy indicators among the elderly in Brazil in 2001 – 2018. Methods. This was an ecological time-series study of new leprosy cases in the elderly reported to the Notifiable Diseases Information System. Prais-Winsten generalized linear regression was used to estimate temporal variations. Results. There were 687 317 new leprosy cases in Brazil from 2001 – 2018, of which 129 214 (18.8%) were among elderly people. Overall detection rates in the elderly and of new cases with grade-2 disability showed a falling trend, with an annual percent change of -4.6% (95%CI = -5.1 to -4.0) and -3.9% (95%CI = -4.6 to -3.2). New case and new multibacillary case proportions showed an increasing trend, with an annual percent change of 2.9% (95%CI = 2.6 to 3.3) and 1.4% (95%CI = 1.0 to 1.7), respectively. Detection rates for new leprosy cases in elderly people in Brazil are decreasing, but the proportion of new cases and multibacillary cases are trending upwards. Conclusions. New cases are shifting to older age groups, and demographic transition and immunosenescence are an influence. Inadequate reduction of grade-2 disability indicates a high risk of physical disability persists. Improved contact tracing and more effective action are needed in this age group.

A tale of two island nations: SARS-COV-2 management in Mauritius and New Zealand (Preprint)

2020 ◽  
Author(s):  
Mohabeer Teeluck ◽  
Ramanand Jeeneea ◽  
Kaviraj S Sukon
Keyword(s):  
New Zealand ◽  
Index Case ◽  
Health Sector ◽  
Cross Sectional Study ◽  
Contact Tracing ◽  
Age Group ◽  
Success Story ◽  
Cross Sectional ◽  
Detection Rates ◽  
Initial Wave

BACKGROUND Mauritius has not had any community acquired SARS-COV-2 case for 6 months and is continuing to maintain control over the disease so far. In this study we discuss how the disease initially spread and use New Zealand, another SARS-COV-2 success story, as the comparator. OBJECTIVE This study aims to explore how the initial wave progressed in Mauritius, by looking at who was most affected, who were most likely to transmit the disease, what were the most effective measures and how the authorities can be best prepared going forward. METHODS Exploratory retrospective analysis of all confirmed cases in Mauritius between 18th March and 30th August 2020. Additionally, a comparative cross-sectional study for confirmed cases between New Zealand and Mauritius. RESULTS There were 355 confirmed cases, 62.0% males, median age = 38 years. The majority (64.8%) were asymptomatic during their infection. New Zealanders in the age-group 10-19 years of age were more prone to infections in contrast to the same age category in Mauritius (P=.006). Contact-tracing was effective in both countries, with 65.3% and 66.3% case detection rates in Mauritius and New Zealand respectively. There were 5 major case clusters in Mauritius and there was an association between delay in notification to authorities and spread from each index case. Health sector workers who were infected, made up of 10.4% of Mauritian cases and 14.3% in New Zealand. The geographical coverage of SARS-COV-2 transmission was 67 percent in Mauritius compared to 45 percent in New Zealand. The test positivity rate was above five percent for only the first three weeks of the outbreak in Mauritius whilst it remained below five percent throughout the outbreak in New Zealand. CONCLUSIONS Mauritius over-achieved in its fight against SARS-COV-2. Application of the lessons learnt will help better face further waves of the pandemic. We outline five recommendations to attain this objective.

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