scholarly journals Quantifying the Impact of Nasopharyngeal Specimen Quality on SARS-CoV-2 Test Performance

2021 ◽  
Author(s):  
Melissa Richard-Greenblatt ◽  
Matthew J Ziegler ◽  
Valerie Bromberg ◽  
Elizabeth Huang ◽  
Hatem Abdallah ◽  
...  
Keyword(s):  
Public Health ◽  
Linear Relationship ◽  
Human Gene ◽  
Health Interventions ◽  
Rt Pcr ◽  
Public Health Interventions ◽  
Gene Target ◽  
Specimen Quality ◽  
The Impact ◽  
Pcr Targeting

Abstract Background The SARS-CoV-2 reverse-transcription polymerase chain reaction (RT-PCR) cycle threshold (Ct) has been used to estimate quantitative viral load, with the goal of targeting isolation precautions for individuals with COVID-19 and guiding public health interventions. However, variability in specimen quality can alter the Ct values obtained from SARS-CoV-2 clinical assays. We sought to define how variable nasopharyngeal (NP) swab quality impacts clinical SARS-CoV-2 test sensitivity. Methods We performed amplification of a human gene target (β-actin) in parallel with a clinical RT-PCR targeting the SARS-CoV-2 ORF1ab gene for 1282 NP specimens collected from patients with clinical concern for COVID-19. We evaluated the relationship between NP specimen quality, characterized by late Ct values for the human gene target β-actin Ct, and the probability of SARS-CoV-2 detection via logistic regression, as well as the linear relationship between SARS-CoV-2 and β-actin Ct. Results Low quality NP swabs are less likely to detect SARS-CoV-2 (odds ratio 0.607, 95%CI 0.487 to 0.753). We observed a positive linear relationship between SARS-CoV-2 and β-actin Ct values (slope 0.181, 95%CI 0.097 to 0.264), consistent with a reduction in detection of 0.181 cycles for each additional cycle of the β-actin target. COVID-19 disease severity was not associated with β-actin Ct values. Conclusions Variability in NP specimen quality significantly impacts the performance of clinical SARS-CoV-2 assays, and caution should be taken when interpreting quantitative SARS-CoV-2 Ct results. If unrecognized, low quality NP specimens, which are characterized by a low level of amplifiable human DNA target, may limit the successful application of SARS-CoV-2 Ct values to direct infection control and public health interventions.

scholarly journals Impact of Nasopharyngeal Specimen Quality on SARS-CoV-2 Test Sensitivity

2020 ◽  
Author(s):  
Melissa Richard-Greenblatt ◽  
Matthew J. Ziegler ◽  
Valerie Bromberg ◽  
Elizabeth Huang ◽  
Hatem Abdallah ◽  
...  
Keyword(s):  
Public Health ◽  
Linear Relationship ◽  
Human Gene ◽  
Health Interventions ◽  
Rt Pcr ◽  
Public Health Interventions ◽  
Gene Target ◽  
Test Sensitivity ◽  
Specimen Quality ◽  
Pcr Targeting

AbstractBackgroundThe SARS-CoV-2 reverse-transcription polymerase chain reaction (RT-PCR) cycle of threshold (Ct) has been used to estimate quantitative viral load, with the goal of targeting isolation precautions for individuals with COVID-19 and guiding public health interventions. However, variability in specimen quality can alter the Ct values obtained from SARS-CoV-2 clinical assays. We sought to define how variable nasopharyngeal (NP) swab quality impacts clinical SARS-CoV-2 test sensitivity.MethodsWe performed amplification of a human gene target (β-actin) in parallel with a clinical RT-PCR targeting the SARS-CoV-2 ORF1ab gene for 1311 NP specimens collected from patients with clinical concern for COVID-19. We evaluated the relationship between NP specimen quality, characterized by high Ct values for the human gene target β-actin Ct, and the probability of SARS-CoV-2 detection via logistic regression, as well as the linear relationship between SARS-CoV-2 and β-actin Ct.ResultsLow quality NP swabs are less likely to detect SARS-CoV-2 (odds ratio 0.654, 95%CI 0.523 to 0.802). We observed a positive linear relationship between SARS-CoV-2 and β-actin Ct values (slope 0.169, 95%CI 0.092 to 0.247). COVID-19 disease severity was not associated with β-actin Ct values.ConclusionsVariability in NP specimen quality accounts for significant differences in the sensitivity of clinical SARS-CoV-2 assays. If unrecognized, low quality NP specimens, which are characterized by a low level of amplifiable human DNA target, may limit the application of SARS-CoV-2 Ct values to direct infection control and public health interventions.

scholarly journals Evolution of disease transmission during the COVID-19 pandemic: patterns and determinants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jie Zhu ◽  
Blanca Gallego
Keyword(s):  
Public Health ◽  
Disease Transmission ◽  
Clustering Algorithm ◽  
Health Interventions ◽  
Transmission Model ◽  
Model Parameters ◽  
Public Health Interventions ◽  
Forecasting Accuracy ◽  
Time Lagged ◽  
The Impact

AbstractEpidemic models are being used by governments to inform public health strategies to reduce the spread of SARS-CoV-2. They simulate potential scenarios by manipulating model parameters that control processes of disease transmission and recovery. However, the validity of these parameters is challenged by the uncertainty of the impact of public health interventions on disease transmission, and the forecasting accuracy of these models is rarely investigated during an outbreak. We fitted a stochastic transmission model on reported cases, recoveries and deaths associated with SARS-CoV-2 infection across 101 countries. The dynamics of disease transmission was represented in terms of the daily effective reproduction number ($$R_t$$ R t ). The relationship between public health interventions and $$R_t$$ R t was explored, firstly using a hierarchical clustering algorithm on initial $$R_t$$ R t patterns, and secondly computing the time-lagged cross correlation among the daily number of policies implemented, $$R_t$$ R t , and daily incidence counts in subsequent months. The impact of updating $$R_t$$ R t every time a prediction is made on the forecasting accuracy of the model was investigated. We identified 5 groups of countries with distinct transmission patterns during the first 6 months of the pandemic. Early adoption of social distancing measures and a shorter gap between interventions were associated with a reduction on the duration of outbreaks. The lagged correlation analysis revealed that increased policy volume was associated with lower future $$R_t$$ R t (75 days lag), while a lower $$R_t$$ R t was associated with lower future policy volume (102 days lag). Lastly, the outbreak prediction accuracy of the model using dynamically updated $$R_t$$ R t produced an average AUROC of 0.72 (0.708, 0.723) compared to 0.56 (0.555, 0.568) when $$R_t$$ R t was kept constant. Monitoring the evolution of $$R_t$$ R t during an epidemic is an important complementary piece of information to reported daily counts, recoveries and deaths, since it provides an early signal of the efficacy of containment measures. Using updated $$R_t$$ R t values produces significantly better predictions of future outbreaks. Our results found variation in the effect of early public health interventions on the evolution of $$R_t$$ R t over time and across countries, which could not be explained solely by the timing and number of the adopted interventions.

The Impact of Public Health Interventions on Delaying and Mitigating against Replacement by SARS-CoV-2 Variants of Concern

2021 ◽  
Author(s):  
Jianhong Wu ◽  
Francesca Scarabel ◽  
Bushra Majeed ◽  
Nicola Luigi Bragazzi ◽  
James Orbinski
Keyword(s):  
Public Health ◽  
Health Interventions ◽  
Public Health Interventions ◽  
The Impact

Syphilis epidemiology and public health interventions in Western Australia from 1991 to 2009

Sexual Health ◽  
2012 ◽  
Vol 9 (3) ◽  
pp. 272 ◽  
Author(s):  
Kellie S. H. Kwan ◽  
Carolien M. Giele ◽  
Heath S. Greville ◽  
Carole A. Reeve ◽  
P. Heather Lyttle ◽  
...  
Keyword(s):  
Public Health ◽  
Western Australia ◽  
Aboriginal People ◽  
Congenital Syphilis ◽  
The United States ◽  
Health Interventions ◽  
Public Health Interventions ◽  
Sex With Men ◽  
Notification Data ◽  
The Impact

Objectives To describe the epidemiology of congenital and infectious syphilis during 1991–2009, examine the impact of public health interventions and discuss the feasibility of syphilis elimination among Aboriginal people in Western Australia (WA). Methods: WA congenital and infectious syphilis notification data in 1991–2009 and national infectious syphilis notification data in 2005–2009 were analysed by Aboriginality, region of residence, and demographic and behavioural characteristics. Syphilis public health interventions in WA from 1991–2009 were also reviewed. Results: During 1991–2009, there were six notifications of congenital syphilis (50% Aboriginal) and 1441 infectious syphilis notifications (61% Aboriginal). During 1991–2005, 88% of notifications were Aboriginal, with several outbreaks identified in remote WA. During 2006–2009, 62% of notifications were non-Aboriginal, with an outbreak in metropolitan men who have sex with men. The Aboriginal : non-Aboriginal rate ratio decreased from 173 : 1 (1991–2005) to 15 : 1 (2006–2009). Conclusions: These data demonstrate that although the epidemiology of syphilis in WA has changed over time, the infection has remained endemic among Aboriginal people in non-metropolitan areas. Given the continued public health interventions targeted at this population, the limited success in eliminating syphilis in the United States and the unique geographical and socioeconomic features of WA, the elimination of syphilis seems unlikely in this state.

The Economics of Infectious Diseases

2018 ◽  
Author(s):  
Katharina Hauck
Keyword(s):  
Public Health ◽  
Infectious Diseases ◽  
Disease Transmission ◽  
Health Interventions ◽  
Health System Strengthening ◽  
Economic Research ◽  
Economic Evaluations ◽  
Research Needs ◽  
Public Health Interventions ◽  
The Impact

Economics can make immensely valuable contributions to our understanding of infectious disease transmission and the design of effective policy responses. The one unique characteristic of infectious diseases makes it also particularly complicated to analyze: the fact that it is transmitted from person to person. It explains why individuals’ behavior and externalities are a central topic for the economics of infectious diseases. Many public health interventions are built on the assumption that individuals are altruistic and consider the benefits and costs of their actions to others. This would imply that even infected individuals demand prevention, which stands in conflict with the economic theory of rational behavior. Empirical evidence is conflicting for infected individuals. For healthy individuals, evidence suggests that the demand for prevention is affected by real or perceived risk of infection. However, studies are plagued by underreporting of preventive behavior and non-random selection into testing. Some empirical studies have shown that the impact of prevention interventions could be far greater than one case prevented, resulting in significant externalities. Therefore, economic evaluations need to build on dynamic transmission models in order to correctly estimate these externalities. Future research needs are significant. Economic research needs to improve our understanding of the role of human behavior in disease transmission; support the better integration of economic and epidemiological modeling, evaluation of large-scale public health interventions with quasi-experimental methods, design of optimal subsidies for tackling the global threat of antimicrobial resistance, refocusing the research agenda toward underresearched diseases; and most importantly to assure that progress translates into saved lives on the ground by advising on effective health system strengthening.

scholarly journals Impact of Public Health Interventions on Seasonal Influenza Activity During the COVID-19 Outbreak in Korea

2020 ◽  
Author(s):  
Hyunju Lee ◽  
Heeyoung Lee ◽  
Kyoung-Ho Song ◽  
Eu Suk Kim ◽  
Jeong Su Park ◽  
...  
Keyword(s):  
Public Health ◽  
Seasonal Influenza ◽  
Health Interventions ◽  
Influenza Surveillance ◽  
Influenza B ◽  
Public Health Interventions ◽  
National Response ◽  
Influenza Activity ◽  
High Level ◽  
The Impact

Abstract Background Coronavirus disease 2019 (COVID-19) was introduced in Korea early with a large outbreak in mid-February. We reviewed the public health interventions used during the COVID-19 outbreak and describe the impact on seasonal influenza activity in Korea. Methods National response strategies, public health interventions and daily COVID-19–confirmed cases in Korea were reviewed during the pandemic. National influenza surveillance data were compared between 7 sequential seasons. Characteristics of each season, including rate of influenza-like illness (ILI), duration of epidemic, date of termination of epidemic, distribution of influenza virus strain, and hospitalization, were analyzed. Results After various public health interventions including enforced public education on hand hygiene, cough etiquette, staying at home with respiratory symptoms, universal mask use in public places, refrain from nonessential social activities, and school closures the duration of the influenza epidemic in 2019/2020 decreased by 6–12 weeks and the influenza activity peak rated 49.8 ILIs/1000 visits compared to 71.9–86.2 ILIs/1000 visits in previous seasons. During the period of enforced social distancing from weeks 9–17 of 2020, influenza hospitalization cases were 11.9–26.9-fold lower compared with previous seasons. During the 2019/2020 season, influenza B accounted for only 4%, in contrast to previous seasons in which influenza B accounted for 26.6–54.9% of all cases. Conclusions Efforts to activate a high-level national response not only led to a decrease in COVID-19 but also a substantial decrease in seasonal influenza activity. Interventions applied to control COVID-19 may serve as useful strategies for prevention and control of influenza in upcoming seasons.

scholarly journals Bayesian Model Averaging with Change Points to Assess the Impact of Vaccination and Public Health Interventions

Epidemiology ◽  
2017 ◽  
Vol 28 (6) ◽  
pp. 889-897 ◽  
Author(s):  
Esra Kürüm ◽  
Joshua L. Warren ◽  
Cynthia Schuck-Paim ◽  
Roger Lustig ◽  
Joseph A. Lewnard ◽  
...  
Keyword(s):  
Public Health ◽  
Bayesian Model ◽  
Bayesian Model Averaging ◽  
Model Averaging ◽  
Health Interventions ◽  
Change Points ◽  
Public Health Interventions ◽  
The Impact

scholarly journals Fistula as a Public Health challenge in Pakistan

2018 ◽  
Vol 13 (2) ◽  
Author(s):  
Shamoon Noushad ◽  
Shershah Syed ◽  
Sadaf Ahmed
Keyword(s):  
Public Health ◽  
Obstetric Fistula ◽  
Secondary Data ◽  
Health Interventions ◽  
Public Health Interventions ◽  
Healthcare Facilities ◽  
Public Health Challenge ◽  
Effective Public Health ◽  
The Impact

Aims: To explore the impact of obstetric fistula in the county and to propose effective public health interventions that can help to prevent the condition with a long-term goal of eradicating the condition. Methods: The survey and analysis included secondary data addressing women's experiences of fistula; dynamics and limitationsdetermining women's access to in healthcare facilities for fistula management; and restraintsof health professional as well as health inequities. Results: It was assessed that recently, many hospitals and organizations in the country go on board on intercessions to address the impact of the illness, however, much importance is on pinpointing and discussing the existing cases rather than focusing on public health interventions that can help to prevent and eventually eradicate the condition in Pakistan.

scholarly journals The Impact of Public Health Interventions on The First and Second Waves of COVID-19 in Trinidad And Tobago – A Simple Epidemic Model

2020 ◽  
Author(s):  
Loren De Freitas ◽  
Han-I Wang
Keyword(s):  
Public Health ◽  
Decision Making ◽  
Trinidad And Tobago ◽  
Specific Treatment ◽  
Health Interventions ◽  
Public Health Interventions ◽  
Support Methods ◽  
The Impact ◽  
Second Wave ◽  
Combined Interventions

Introduction The COVID-19 pandemic has resulted in more than 35 million confirmed cases worldwide. Currently, there is no specific treatment for the disease or available vaccine to reduce the spread of COVID-19. As such, countries rely on a range of public health interventions to assist in halting the spread of transmission. Caribbean countries have also adopted many public health interventions. In this paper, we use mathematical modelling to demonstrate the impact of public health interventions on the progression of COVID-19 in order to provide timely decision support. Methods A cohort Markov model, based on the concept of the SEIR model, was built to reflect the characteristics of the COVID-19 virus. Five possible public health interventions in the first wave and a projection of current second wave were simulated using the constructed model. Results The model results indicate that the strictest combined interventions of complete border closure and lockdown were the most effective with the number of deaths less than ten in the first wave. For the current second wave, it will take around 30 days for the pandemic to pass its peak after implementing the wearing of face masks policy. Conclusions This paper shows the impact of common public health interventions on the COVID-19 pandemic, using Trinidad and Tobago as an example. Such impacts may be useful in reducing delays in decision-making and improving compliance by populations. However, given the limitations associated with mathematical models, decision-making should be guided by economic assessments, infectious disease and public health expertise.

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