Saliva-Based, COVID-19 RT-PCR Pooled Screening Strategy to Keep Schools Open

2022 ◽  
pp. 1-6
Author(s):  
Sofia Perea ◽  
Kyle Tretina ◽  
Kirk N. O’Donnell ◽  
Rebecca Love ◽  
Gabor Bethlendy ◽  
...  
Keyword(s):  
School Safety ◽  
Control Program ◽  
Screening Strategy ◽  
Contact Tracing ◽  
Rt Pcr ◽  
School Closures ◽  
Children And Adolescent ◽  
Work From Home ◽  
Screening Protocol ◽  
Before School

Abstract Background: As of March 2020, governments throughout the world implemented business closures, work from home policies, and school closures due to exponential increase of coronavirus disease 2019 (COVID-19) cases, leaving only essential workers being able to work on site. For most of the children and adolescent school closures during the first lockdown had significant physical and psychosocial consequences. Here, we describe a comprehensive Return to School program based on a behavior safety protocol combined with the use of saliva-based reverse transcriptase-polymerase chain reaction (RT-PCR) pooled screening technique to keep schools opened. Methods: The program had 2 phases: before school (safety and preparation protocols) and once at school (disease control program: saliva-based RT-PCR pooled screening protocol and contact tracing). Pooling: Aliquots of saliva from 24 individuals were pooled and 1 RT-PCR test was performed. If positive, the initial 24-pool was then retested (12 pools of 2). Individual RT-PCR tests from saliva samples from positive pools of 2 were performed to get an individual diagnosis. Results: From August 31 until December 20, 2020 (16-wk period) a total of 3 pools, and subsequent 3 individual diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) disease were reported (2 teachers and 1 staff). Conclusion: Until COVID-19 vaccine can be administered broadly to all-age children, saliva-based RT-PCR pooling testing is the missing piece we were searching for to keep schools opened.

scholarly journals Can a ‘3-tier Screening’ Strategy be Adopted during COVID-19 Pandemic for Safer Air Travel and to Help Curb its Spread Across Borders?

2021 ◽  
Vol 1 (1) ◽  
pp. 62-64
Author(s):  
Mohammad Shahid
Keyword(s):  
Detection Method ◽  
Screening Strategy ◽  
Air Travel ◽  
Antigen Detection ◽  
Destination Country ◽  
Rt Pcr ◽  
Screening Protocol ◽  
Entire World ◽  
Pcr Test

Since the appearance of SARS-CoV-2 in 2019, it spread quickly crossing geographical borders and thus affected almost the entire world. It was alarming to note its quick spread, which obviously was due to the increased frequency and ease of air travel in this era. Currently, many airlines (and countries too) have a prerequisite to have a negative COVID-19 RT-PCR test within 72 hrs. prior to boarding the flight. Although all the necessary precautions are strictly enforced during air travel, there is still a possibility that a person with a negative COVID-19 test (RT-PCR) around 72hrs prior to boarding the flight would have an infection and that the person would pass it on to fellow passengers on board and thus can further spread SARS-CoV-2 infection into the community if robust action is not initiated. There is also a subconscious apprehension among the passengers that co-passengers may have an infection on board. This is especially worrisome seeing the appearance of new variants recently. Here I present the logistics for a ‘3-tier screening’ protocol (1st test by RT-PCR within 72hrs of the flight schedule, 2nd test by rapid antigen detection method 1-5hrs prior to flight schedule, 3rd test post-arrival or to follow the destination country post-arrival protocol), which would at least provide an extra filter to separate the recently identified positive cases and thus prevent the spread of this threatening disease across the borders.

scholarly journals Modeling the impact of school reopening and contact tracing strategies on Covid-19 dynamics in different epidemiologic settings in Brazil

2021 ◽  
Author(s):  
Marcelo Eduardo Borges ◽  
Leonardo Souto Ferreira ◽  
Silas Poloni ◽  
Ângela Maria Bagattini ◽  
Caroline Franco ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Transmission Rate ◽  
Disease Incidence ◽  
Demographic Data ◽  
School Closure ◽  
Mitigation Measures ◽  
Contact Tracing ◽  
School Closures ◽  
Infection Transmission ◽  
The Impact

Among the various non–pharmaceutical interventions implemented in response to the Covid–19 pandemic during 2020, school closures have been in place in several countries to reduce infection transmission. Nonetheless, the significant short and long–term impacts of prolonged suspension of in–person classes is a major concern. There is still considerable debate around the best timing for school closure and reopening, its impact on the dynamics of disease transmission, and its effectiveness when considered in association with other mitigation measures. Despite the erratic implementation of mitigation measures in Brazil, school closures were among the first measures taken early in the pandemic in most of the 27 states in the country. Further, Brazil delayed the reopening of schools and stands among the countries in which schools remained closed for the most prolonged period in 2020. To assess the impact of school reopening and the effect of contact tracing strategies in rates of Covid–19 cases and deaths, we model the epidemiological dynamics of disease transmission in 3 large urban centers in Brazil under different epidemiological contexts. We implement an extended SEIR model stratified by age and considering contact networks in different settings – school, home, work, and elsewhere, in which the infection transmission rate is affected by various intervention measures. After fitting epidemiological and demographic data, we simulate scenarios with increasing school transmission due to school reopening. Our model shows that reopening schools results in a non–linear increase of reported Covid-19 cases and deaths, which is highly dependent on infection and disease incidence at the time of reopening. While low rates of within[&ndash]school transmission resulted in small effects on disease incidence (cases/100,000 pop), intermediate or high rates can severely impact disease trends resulting in escalating rates of new cases even if other interventions remain unchanged. When contact tracing and quarantining are restricted to school and home settings, a large number of daily tests is required to produce significant effects of reducing the total number of hospitalizations and deaths. Our results suggest that policymakers should carefully consider the epidemiological context and timing regarding the implementation of school closure and return of in-person school activities. Also, although contact tracing strategies are essential to prevent new infections and outbreaks within school environments, our data suggest that they are alone not sufficient to avoid significant impacts on community transmission in the context of school reopening in settings with high and sustained transmission rates.

scholarly journals COVID-19 in a Rural Community: Outbreak Dynamics, Contact Tracing and Environmental RNA

2020 ◽  
Author(s):  
Isabel G. Fernández de Mera ◽  
Francisco J. Rodríguez del Río ◽  
José de la Fuente ◽  
Marta Pérez Sancho ◽  
Dolores Hervas ◽  
...  
Keyword(s):  
Rural Community ◽  
Public Service ◽  
Contact Tracing ◽  
Rt Pcr ◽  
Rna Surveillance ◽  
Petrol Station ◽  
Early Testing ◽  
Resource Deployment ◽  
The Village ◽  
Close Contacts

Background: Since March 2020, Spain is severely hit by the ongoing pandemic of coronavirus disease 19 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Understanding and disrupting the early transmission dynamics of the infection is crucial for impeding sustained transmission. Methods: We recorded all COVID-19 cases and traced their contacts in an isolated rural community. We also sampled 10 households, 6 public service sites and the wastewater from the village sewage for environmental SARS-CoV-2 RNA. Results: The first village patient diagnosed with COVID-19-compatible symptoms occurred on March 3, 2020, twelve days before lockdown. A peak of 39 cases occurred on March 30. By May 15, the accumulated number of symptomatic cases was 53 (6% of the population), of which only 22 (41%) had been tested and confirmed by RT-PCR as SARS-CoV-2 infected, including 16 hospitalized patients. Contacts (n=144) were six times more likely to develop symptoms. Environmental sampling detected SARS-CoV-2 RNA in two households with known active cases and in two public service sites: the petrol station and the pharmacy. Samples from other sites and the wastewater tested negative. Conclusions: The low proportion of patients tested by RT-PCR calls for urgent changes in disease management. We propose that early testing of all cases and their close contacts would reduce infection spread, reducing the disease burden and fatalities. In a context of restricted testing, environmental RNA surveillance might prove useful for early warning and to identify high-risk settings enabling a targeted resource deployment.

scholarly journals Epidemiological Survey and Screening Strategy for Dengue Virus in Blood Donors from Yunnan Province

2020 ◽  
Author(s):  
LING LI ◽  
YING LI ◽  
Shaofang Lu ◽  
Jing Dong ◽  
Haixia Xu ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Prevalence Rate ◽  
Screening Strategy ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Igm Antibodies ◽  
Blood Center ◽  
Nonstructural Protein 1 ◽  
Elisa Testing

Abstract BACKGROUND Dengue virus (DENV) can be transmitted through blood transfusion. DENV was not screened regularly in Xishuangbanna Blood Center. This study was conducted in Xishuangbanna Blood Center with an attempt to develop DENV screening strategies in one of China’s high-incidence areas.METHODS Blood samples were collected randomly between June 2019 and August 2019. These samples were first screened for dengue IgG and IgM antibodies using enzyme-linked immunosorbent assay (ELISA). All reactive samples and some randomly-chosen non-reactive samples were used to detect DENV RNAs using real time polymerase-chain-reaction (RT-PCR) assay. After RT-PCR assay, these samples were further tested for soluble nonstructural protein 1 (NS1) using colloidal gold method. The demographic data of DENV positive donors were collected.RESULTS A total of 2,254 donor samples were collected and tested for dengue IgG and IgM antibodies by ELISA between June 2019 and August 2019. ELISA testing revealed that 598 donor samples were anti-IgG and/or anti-IgM reactive, with a serological prevalence rate of 26.53%. Among all the donor samples, 26 were RT-PCR positive and/or NS1 positive. Moreover, there were significant differences in the prevalence rate of DENV in terms of occupation (P=0.001), education(P<0.001) and ethnicity (P=0.026). CONCLUSION The prevalence of DENV in Xishuangbanna Blood Center was higher than most other blood centers that have implemented DENV donor screening. Our study provides the first-hand data about the prevalence of DENV and allows development of a screening strategy for clinical use.

scholarly journals False Negative Mitigation in Group Testing for COVID-19 Screening

2021 ◽  
Vol 8 ◽  
Author(s):  
Amir Reza Alizad Rahvar ◽  
Safar Vafadar ◽  
Mehdi Totonchi ◽  
Mehdi Sadeghi
Keyword(s):  
Viral Load ◽  
False Negative ◽  
Group Testing ◽  
False Negative Rate ◽  
Screening Strategy ◽  
Web Interface ◽  
Rt Pcr ◽  
Promising Candidate ◽  
Testing Method ◽  
High False Negative Rate

After lifting the COVID-19 lockdown restrictions and opening businesses, screening is essential to prevent the spread of the virus. Group testing could be a promising candidate for screening to save time and resources. However, due to the high false-negative rate (FNR) of the RT-PCR diagnostic test, we should be cautious about using group testing because a group's false-negative result identifies all the individuals in a group as uninfected. Repeating the test is the best solution to reduce the FNR, and repeats should be integrated with the group-testing method to increase the sensitivity of the test. The simplest way is to replicate the test twice for each group (the 2Rgt method). In this paper, we present a new method for group testing (the groupMix method), which integrates two repeats in the test. Then we introduce the 2-stage sequential version of both the groupMix and the 2Rgt methods. We compare these methods analytically regarding the sensitivity and the average number of tests. The tradeoff between the sensitivity and the average number of tests should be considered when choosing the best method for the screening strategy. We applied the groupMix method to screening 263 people and identified 2 infected individuals by performing 98 tests. This method achieved a 63% saving in the number of tests compared to individual testing. Our experimental results show that in COVID-19 screening, the viral load can be low, and the group size should not be more than 6; otherwise, the FNR increases significantly. A web interface of the groupMix method is publicly available for laboratories to implement this method.

scholarly journals O-104 Low SARS-CoV-2 positivity rate in women included in ART programs following the recommendations of the Spanish scientific societies on reproduction (SEF/ASEBIR)

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
D Mataro ◽  
I Cuevas-Saiz ◽  
J A Castilla ◽  
J A Dominguez ◽  
N Prados ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Intrauterine Insemination ◽  
Cross Sectional Study ◽  
Screening Strategy ◽  
Clinical Interview ◽  
The Other ◽  
Medical Procedure ◽  
Rt Pcr ◽  
Cross Sectional ◽  
Aggregated Data

Abstract Study question What is the SARS-CoV-2 positivity rate following the Spanish Fertility Society (SEF)/Association for the Study of Reproductive Biology (ASEBIR) screening recommendations? Summary answer The SARS-CoV-2 positivity rate in the centers following the SEF/ASEBIR screening recommendations was 0.316% after the first survey and 0.364% after the second one What is known already Due to the Sars-Cov-2 pandemic, all the Medical Assisted Reproduction (MAR) centers in Spain had to interrupt their activity most of the time during the first pandemic wave. On April 27th activity was restarted, and SEF and ASEBIR jointly elaborated a guide describing their SARS-CoV-2 screening recommendations for MAR centers. This document aims to achieve a safe environment for patients and staff. It includes the possibility of screening patients through a targeted clinical interview and the use of reverse-transcriptase polymerase chain reaction (RT-PCR). The aim of this study is to quantify the SARS-CoV-2 positivity rate based on these recommendations. Study design, size, duration National multicenter cross-sectional study. Information was gathered from centers using an anonymous survey asking for aggregated data about the number of positive cases among screened patients, sent twice. The first survey covered the period April 27th - June 30th. Second survey covered July 1st - August 31st. Response rates among centres were 9% (29/319) and 6% (20/319), respectively. This study includes 2,695 and 4,068 screenings performed in the first and the second survey, respectively. Participants/materials, setting, methods The SEF/ASEBIR recommendations describe two screening strategies. Strategy (a) consists in a targeted clinical interview (TCI) evaluating clinical symptoms and exposure risk, first before starting the cycle, and before egg-retrieval, intrauterine insemination (IUI), and/or embryo transfer (ET). Suspicious cases could be confirmed by further RT-PCR testing. Strategy (b) consists in conducting the same first TCI, and a systematic RT-PCR testing before the medical procedure in all patients. All patients in both strategies have a TCI. Main results and the role of chance In the 1st survey, 1,177 screenings and 919 RT-PCR (78.07%) were performed before the egg-retrieval. One patient with a negative TCI and positive RT-PCR was detected, and the cycle was cancelled. 1,518 screenings and 1,161 RT-PCRs (76.48%) were performed before the ET/IUI. Two patients with a positive TCI were detected, one did not perform a RT-PCR, while the other resulted in a positive RT-PCR. Both cycles were cancelled. Besides, 5 patients with negative TCI performed a RT-PCR with a positive result; all 5 were cancelled. Overall, the SARS-CoV-2 positivity rate was 8/2533 (0.316%), of which 7/2533 (0.276%) were identified by RT-PCR testing. The 2nd survey included 1,376 screenings and 1,009 RT-PCR (73.32%) performed before the egg-retrieval. Four patients with negative TCI and further positive RT-PCR were detected, and their cycle was cancelled. 2,692 screenings and 2,134 RT-PCR (79.27%) were performed before ET/IUI. Two patients had a positive TCI, one with a negative, the other with a positive RT-PCR testing; both cycles were cancelled. Besides, 8 patients with negative TCI, but positive RT-PCR testing, were detected and their cycles cancelled. Overall, the SARS-CoV-2 positivity rate was 14/3846 (0.364%), of which 13/3846 (0.338%) after positive RT-PCR testing. Limitations, reasons for caution The criteria for performing the RT-PCR testing were not the same in all MAR Centres or even in the same centre at different times. Due to the low response rate of the study, we should not extend these results to all the MAR Centres in Spain. Wider implications of the findings The results of the surveys suggest that the SEF/ASEBIR recommendations could be a good screening strategy for SARS-Cov-2 at MAR Centres. Further survey collected at different times of the pandemic are warranted, including new strategies for screening as antigen tests or vaccination status. Trial registration number Not applicable

Using Test Positivity Rate (TPR) as an Indicator for Strategic Action in COVID-19: A Situational Analysis in Kerala, India

2021 ◽  
pp. 263394472110542
Author(s):  
Raman Swathy Vaman ◽  
Mathew J. Valamparampil ◽  
Anu Elizabeth Augustine
Keyword(s):  
Time Frame ◽  
Contact Tracing ◽  
Situational Analysis ◽  
New Wave ◽  
Primary Care System ◽  
Rt Pcr ◽  
Strategic Action ◽  
Daily Change ◽  
Timely Fashion ◽  
Polymerase Chain

Administrators and policymakers have relied on test positivity rate (TPR) for making policy decisions regarding local, regional, and national lockdowns. It has the advantage of easily available data with an easy technique for calculation on day-to-day basis. However, concerns are being raised regarding its use as a sole indicator for determining movement restrictions and lockdowns. The present review provides a perspective of the alterations in TPR in Kasaragod district of Kerala during the first half of 2021. The variations in the number of antigen and reverse transcription polymerase chain reaction (rt-PCR) tests along with the trend of proportion of rt-PCR test are depicted. In places like Kerala where primary care system and contact tracing is comparatively robust than several other regions, testing the appropriate persons in a timely fashion alone is sufficient to cause an upswing in the TPR. Rather than daily change, the overall change in a larger time frame of 1 to 2 weeks could give early warning regarding the emergence of a new wave. TPR alone may not be able to reflect the transmission patterns of COVID-19. Using 7-day median value of TPR along with weekly tests done per 10,000 population, 7-day rolling average of active cases per 10,000 population, or daily number of new positive cases per 10,000 population could bring out a more composite indicator. Such an indicator reflecting the disease dynamics at regional levels will enable people to improve their livelihood without compromising on COVID-19.

scholarly journals Current Avenues for COVID-19 Serology

2020 ◽  
Vol 56 (02) ◽  
pp. 087-090
Author(s):  
Saumya Srivastava ◽  
Vidhi Jain ◽  
Vijaya Lakshmi Nag ◽  
Sanjeev Misra ◽  
Kuldeep Singh
Keyword(s):  
Polymerase Chain Reaction ◽  
Gold Standard ◽  
Diagnostic Tests ◽  
Immune Status ◽  
Contact Tracing ◽  
Great Promise ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Diagnostic Assays ◽  
Polymerase Chain

AbstractDevelopment of rapid, reliable, and easy diagnostic tests with high-throughput is the need of the hour for laboratories combating the COVID-19 pandemic. While real-time polymerase chain reaction (RT-PCR) is the gold standard for diagnosing active infections, it is expensive and time-consuming. Serological diagnostic assays with a premise to aid rapid contact tracing, immune status determination, and identification of potential convalescent plasma donors hold great promise. Timely diagnosis, effective treatment, and future prevention are key to management of COVID-19.

scholarly journals Reducing contacts to stop SARS-CoV-2 transmission during the second pandemic wave in Brussels, Belgium

2020 ◽  
Author(s):  
Brecht Ingelbeen ◽  
Laurène Peckeu ◽  
Marie Laga ◽  
Ilona Hendrix ◽  
Inge Neven ◽  
...  
Keyword(s):  
European Commission ◽  
Risk Ratio ◽  
Reproduction Number ◽  
Case Reports ◽  
Contact Tracing ◽  
Social Mixing ◽  
Before School ◽  
Specific Number ◽  
Pandemic Wave ◽  
Close Contacts

AbstractBackgroundReducing contacts is a cornerstone of containing SARS-CoV-2. We evaluated the effect of physical distancing measures and of school reopening on contacts and consequently on SARS-CoV-2 transmission in Brussels, a hotspot during the second European wave.MethodsUsing SARS-CoV-2 case reports and contact tracing data during August-November 2020, we estimated changes in the age-specific number of reported contacts. We associated these trends with changes in the instantaneous reproduction number Rt and in age-specific transmission-events during distinct intervention periods in the Brussels region. Furthermore, we analysed trends in age-specific case numbers, pre- and post-school opening.FindingsWhen schools reopened and physical distancing measures relaxed, the weekly mean number of reported contacts surged from 2.01 (95%CI 1.73-2.29) to 3.04 (95%CI 2.93-3.15), increasing across all ages. The fraction of cases aged 10-19 years started increasing before school reopening, with no further increase following school reopening (risk ratio 1.23, 95%CI 0.79-1.94). During the subsequent month, 8.9% (67/755) of infections identified were from teenagers to other ages, while 17.0% (131/755) from other ages to teenagers. Rt peaked mid-September at 1.48 (95%CI 1.35-1.63). Reintroduction of physical distancing measures reduced reported contacts to 1.85 (95%CI 1.78-1.91), resulting in Rt dropping below 1 within 3 weeks.InterpretationThe second pandemic wave in Brussels was the result of increased contacts across all ages following school reopening. Stringent physical distancing measures, including closure of bars and limiting close contacts while schools remain open, reduced social mixing, in turn controlling SARS-CoV-2 transmission.FundingEuropean Commission H2020. GGC Brussel.

scholarly journals Detailed Overview of the Buildout and Integration of an Automated High-Throughput CLIA Laboratory for SARS-CoV-2 Testing on a Large Urban Campus

2021 ◽  
Author(s):  
Lena Landaverde ◽  
David McIntyre ◽  
James Robson ◽  
Dany Fu ◽  
Luis Ortiz ◽  
...  
Keyword(s):  
High Throughput ◽  
The United States ◽  
Clinical Testing ◽  
Rt Pcr ◽  
Testing Laboratory ◽  
Boston University ◽  
The Us ◽  
Screening Protocol ◽  
Urban Campus ◽  
Academic Year

In 2019, the first cases of SARS-CoV-2 were detected in Wuhan, China, and by early 2020 the cases were identified in the United States. SARS-CoV-2 infections increased in the US causing many states to implement stay-at-home orders and additional safety precautions to mitigate potential outbreaks. As policies changed throughout the pandemic and restrictions lifted, there was an increase in demand for Covid-19 testing which was costly, difficult to obtain, or had long turn-around times. Some academic institutions, including Boston University, created an on-campus Covid-19 screening protocol as part of planning for the safe return of students, faculty, and staff to campus with the option for in-person classes. At BU, we stood up an automated high-throughput clinical testing lab with the capacity to run 45,000 individual tests weekly by fall of 2020, with a purpose-built clinical testing laboratory, a multiplexed RT-PCR test, robotic instrumentation, and trained CLIA certified staff. There were challenges to overcome, including the supply chain issues for PPE testing materials, and equipment that were in high demand. The Boston University Clinical Testing Laboratory was operational at the start of the fall 2020 academic year. The lab performed over 1 million SARS-CoV-2 RT-PCR tests during the 2020-2021 academic year.

Sign in / Sign up

Export Citation Format

Share Document