Pooling in a Pod: A Strategy for COVID-19 Testing to Facilitate a Safe Return to School

The COVID-19 pandemic prompted widespread closures of primary and secondary schools. Routine testing of asymptomatic students and staff members, as part of a comprehensive mitigation program, can help schools open safely. “Pooling in a pod” is a public health surveillance strategy whereby testing cohorts (pods) are based on social relationships and physical proximity. Pooled testing provides a single laboratory test result for the entire pod, rather than a separate result for each person in the pod. During the 2020-2021 school year, an independent preschool–grade 12 school in Washington, DC, used pooling in a pod for weekly on-site point-of-care testing of all staff members and students. Staff members and older students self-collected anterior nares samples, and trained staff members collected samples from younger students. Overall, 12 885 samples were tested in 1737 pools for 863 students and 264 staff members from November 30, 2020, through April 30, 2021. The average pool size was 7.4 people. The average time from sample collection to pool test result was 40 minutes. The direct testing cost per person per week was $24.24, including swabs. During the study period, 4 surveillance test pools received positive test results for COVID-19. A post-launch survey found most parents (90.3%), students (93.4%), and staff members (98.8%) were willing to participate in pooled testing with confirmatory tests for pool members who received a positive test result. The proportion of students in remote learning decreased by 62.2% for students in grades 6-12 ( P < .001) and by 92.4% for students in preschool to grade 5 after program initiation ( P < .001). Pooling in a pod is a feasible, cost-effective surveillance strategy that may facilitate safe, sustainable, in-person schooling during a pandemic.

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SafeSwab, a sample collection and dispensing device for near-patient testing

10.1101/2021.08.20.21262386 ◽

2021 ◽

Author(s):

Thomas E Grys ◽

Kathrine McAulay ◽

Darrell Ingram ◽

Craig Duffy ◽

Ashley Williams ◽

...

Keyword(s):

Los Angeles ◽

Health Systems ◽

Point Of Care ◽

Digital Health ◽

Rapid Test ◽

Sample Collection ◽

Patient Instruction ◽

Self Testing ◽

Test Result ◽

Rapid Test Result

The COVID-19 pandemic has accelerated the pace of innovation around virtual care visits and testing technology. Here we present the SafeSwab (Safe Health Systems, Los Angeles, CA), an integrated, universal sample collection and dispensing device that is designed to minimize user error and enable rapid testing in a point of care or self-testing format. The SafeSwab was used with the Safe Health Systems HealthCheck digital health application to enable self-testing by patients using lateral flow tests for SARS-CoV-2 antigen or for antibodies against SARS-CoV-2. Patients (n=74) using the SafeSwab produced a valid rapid test result in 96% of attempts, and 96% of patients felt confident that they had collected a good sample. The Safe HealthCheck app has an integrated image analysis algorithm, AutoAdapt LFA, that interprets a picture of a rapid test result, and the algorithm interpreted the result correctly 100% of the time. The SafeSwab was found to be versatile and easy to use for both self-collected nasal sampling as well as fingerstick blood sampling. The use of Safe Health Systems HealthCheck app allows an integrated solution for patient instruction and test interpretation

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Point-of-Care/Chairside aMMP-8 Analytics of Periodontal Diseases’ Activity and Episodic Progression

Diagnostics ◽

10.3390/diagnostics8040074 ◽

2018 ◽

Vol 8 (4) ◽

pp. 74 ◽

Cited By ~ 16

Author(s):

Ismo Räisänen ◽

Anna Heikkinen ◽

Eva Siren ◽

Taina Tervahartiala ◽

Dirk-Rolf Gieselmann ◽

...

Keyword(s):

Point Of Care ◽

Periodontal Diseases ◽

Cost Effective ◽

Disease Status ◽

Tissue Destruction ◽

Treatment Needs ◽

Cross Sectional ◽

Treatment Need ◽

Periodontal Index ◽

Test Result

Traditional periodontal disease diagnostics are based mainly on clinical examination and radiographs. They assess only past tissue destruction and provide no information on the current disease status or its future progression. The objective is to find out if an active matrix metalloproteinase-8 (aMMP-8) point-of-care (PoC) test could provide a cost-effective way to get around this limitation. This cross-sectional study used 47 adolescents and 70 adults, who were clinically examined and their aMMP-8 PoC tested. The aMMP-8 PoC test results and patients’ treatment need, based on the community periodontal index of treatment needs (CPITN), were compared and analyzed using Fisher’s exact test. In terms of CPITN, the aMMP-8 PoC test gave no false positives for both adolescents and adults. All healthy patients got a negative test result, while a positive test result indicated periodontal treatment need correctly. Finally, there was a significant association between a patient’s aMMP-8 PoC test result and his/her treatment need (p = 0.001 for adolescents, p = 0.001 for adults). In conclusion, more accurate diagnostics of periodontal diseases’ activity and progression using an aMMP-8 PoC test may help to reduce oral health care costs by reducing patient overtreatment, improving patient outcome, and reducing the need for complex periodontal therapy.

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Evaluation of SARS-CoV-2 rapid antigen diagnostic tests for saliva samples

10.1101/2021.05.14.21257100 ◽

2021 ◽

Author(s):

Marie Hagbom ◽

Noelia Carmona-Vicente ◽

Sumit Sharma ◽

Henrik Olsson ◽

Mikael Jamtberg ◽

...

Keyword(s):

Disease Transmission ◽

Nucleocapsid Protein ◽

Limit Of Detection ◽

Point Of Care ◽

Rapid Test ◽

Cost Effective ◽

Rapid Response ◽

Diagnostic Tools ◽

Sample Collection ◽

Saliva Test

Background: The COVID-19 pandemic has highlighted the need for rapid, cost effective and easy-to-use diagnostic tools for SARS-CoV-2 rapid antigen detection (RAD) for use in point of care settings or as self-tests, to limit disease transmission. Using saliva samples would further greatly facilitate sample collection, diagnostic feasibility, and mass screening. Objective: We tested two rapid antigen immunochromatographic tests designed for detection of SARS-CoV-2 in saliva: Rapid Response COVID-19 Antigen Rapid Test Cassette for oral fluids (Rapid Response) and DIAGNOS COVID-19 Antigen Saliva Test (DIAGNOS). Evaluation of detection limit was performed with purified SARS-CoV-2 nucleocapsid protein and titrated live SARS-CoV-2 virus and compared to Abbott Panbio COVID-19 Ag Rapid Test (Panbio) designed for nasopharyngeal samples. Sensitivity and specificity were further evaluated on RT-qPCR positive and negative saliva samples from individuals hospitalized with COVID-19 (n=34); and asymptomatic health care personnel (n=20). Results: The limit of detection of the saliva test from DIAGNOS was comparable with the Panbio test and showed higher sensitivity than Rapid Response for both nucleocapsid protein and diluted live viruses. DIAGNOS and Rapid Response further detected seven (47%) and five (33%), respectively, of the 15 RT-qPCR positive saliva samples in individuals hospitalized with COVID-19. Of the 39 RT-qPCR negative samples, all were negative with both tests (specificity 100%; 95% c.i. 0.91-1.00). Only one of the RT-qPCR positive saliva samples (Ct 21.6) contained infectious virus as determined by cell culture and was also positive using the saliva RADs. Conclusion: The results show that the DIAGNOS test exhibit a similar limit of detection as the Panbio RAD and may be an important and easy-to-use saliva RAD complement to detect infectious individuals.

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Pooled testing efficiency increases with test frequency

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2105180119 ◽

2022 ◽

Vol 119 (2) ◽

pp. e2105180119

Author(s):

Ned Augenblick ◽

Jonathan Kolstad ◽

Ziad Obermeyer ◽

Ao Wang

Keyword(s):

Cost Effective ◽

Short Paper ◽

Infection Rates ◽

Repeated Testing ◽

Pooled Testing ◽

Testing Frequency ◽

Rapid Spread ◽

Natural Sampling ◽

Testing Cost ◽

Frequent Testing

Pooled testing increases efficiency by grouping individual samples and testing the combined sample, such that many individuals can be cleared with one negative test. This short paper demonstrates that pooled testing is particularly advantageous in the setting of pandemics, given repeated testing, rapid spread, and uncertain risk. Repeated testing mechanically lowers the infection probability at the time of the next test by removing positives from the population. This effect alone means that increasing frequency by x times only increases expected tests by around x. However, this calculation omits a further benefit of frequent testing: Removing infections from the population lowers intragroup transmission, which lowers infection probability and generates further efficiency. For this reason, increasing testing frequency can paradoxically reduce total testing cost. Our calculations are based on the assumption that infection rates are known, but predicting these rates is challenging in a fast-moving pandemic. However, given that frequent testing naturally suppresses the mean and variance of infection rates, we show that our results are very robust to uncertainty and misprediction. Finally, we note that efficiency further increases given natural sampling pools (e.g., workplaces, classrooms) that induce correlated risk via local transmission. We conclude that frequent pooled testing using natural groupings is a cost-effective way to provide consistent testing of a population to suppress infection risk in a pandemic.

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Point-of-care detection of SARS-CoV-2 in nasopharyngeal swab samples using an integrated smartphone-based centrifugal microfluidic platform

10.1101/2020.11.04.20225888 ◽

2020 ◽

Author(s):

Ruben R. G. Soares ◽

Ahmad S. Akhtar ◽

Inês F. Pinto ◽

Noa Lapins ◽

Donal Barrett ◽

...

Keyword(s):

Direct Detection ◽

Point Of Care ◽

Cost Effective ◽

Nucleic Acid Amplification ◽

Nasopharyngeal Swab ◽

Sample Collection ◽

Resource Limited Settings ◽

Microfluidic Platform ◽

Agarose Beads ◽

Resource Limited

AbstractWith its origin estimated around December 2019 in Wuhan, China, the ongoing 2020 SARS-CoV-2 pandemic is a major global health challenge, resulting in more than 45 million infections and 1.2 million deaths. The demand for scalable, rapid and sensitive viral diagnostics is thus particularly pressing at present to help contain the rapid spread of infection and prevent overwhelming the capacity of health systems. While high-income countries have managed to rapidly expand diagnostic capacities, such is not the case in resource-limited settings of low- to medium-income countries.Aiming at developing cost-effective viral load detection systems for point-of-care COVID-19 diagnostics in resource-limited and resource-rich settings alike, we report the development of an integrated modular centrifugal microfluidic platform to perform loop-mediated isothermal amplification (LAMP) of viral RNA directly from heat-inactivated nasopharyngeal swab samples. The discs were pre-packed with dried n-benzyl-n-methylethanolamine modified agarose beads used as a versatile post-nucleic acid amplification signal enhancement strategy, allowing fluorescence detection via a smartphone camera and simple optics. The platform provided sample-to-answer analysis within 1 hour from sample collection and a detection limit between 100 and 1000 RNA copies in 10 μL reaction volume. Furthermore, direct detection of non-extracted SARS-CoV-2 RNA in nasopharyngeal swab samples from patients with Ct values below 26 (n=25 plus 6 PCR negative samples) was achieved with ∼94% sensitivity and 100% specificity, thus being fit-for-purpose to diagnose patients with a high risk of viral transmission. These results show significant promise towards bringing routine point-of-care COVID-19 diagnostics closer to resource-limited settings.

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Pooling-in-a-pod: A Strategy for COVID-19 Testing to Facilitate Safe Return to School

10.1101/2021.03.24.21254230 ◽

2021 ◽

Author(s):

Ethan M. Berke ◽

Lori M. Newman ◽

Suzanna Jemsby ◽

Natasha Bhalla ◽

Natalie E. Sheils ◽

...

Keyword(s):

Public Health ◽

Social Relationships ◽

Public Health Surveillance ◽

Point Of Care ◽

Public Health Practice ◽

Health Surveillance ◽

Pool Size ◽

Sample Collection ◽

Surveillance Strategy ◽

Physical Proximity

ABSTRACTThe COVID-19 pandemic has prompted widespread primary and secondary school closures. Routine testing of asymptomatic students and staff, as part of a comprehensive program, can help schools open safely. “Pooling-in-a-pod” is a public health surveillance strategy whereby testing cohorts are composed based on social relationships and physical proximity. Pooling-in-a-pod allowed for weekly on-site point-of-care testing of all staff and students at an independent preschool to grade 12 school in Washington, D.C. Staff and older students self-collected anterior nares samples, and trained staff collected samples from younger students. Overall, 6,746 samples were tested for 815 students and 276 staff between November 30, 2020, and March 3, 2021. The average pool size was 7.3 people. Sample collection to pool result time averaged 40 minutes. The direct testing cost per person per week was $24.77, including swabs. One surveillance test pool was positive. During the study period, daily new cases in Washington, D.C., ranged from 24 – 46 per 100,000 population. A post-launch survey found most parents (90.3%), students (93.4%), and staff (98.8%) were willing to participate in pooled testing with confirmatory tests for positive pool members. The school reported a 32.6% decrease in virtual learning after initiation of the program. Pooling-in-a-pod is feasible, cost-effective, and an acceptable COVID-19 surveillance strategy for schools. School officials and policymakers can leverage this strategy to facilitate safe, sustainable, in-person schooling.SUMMARY1)What is the current understanding of this subject?Routine COVID-19 testing as part of a comprehensive strategy to operate schools safely is currently not widely implemented.2)What does this report add to the literature?“Pooling-in-a-pod,” is a public health surveillance strategy whereby cohorts are composed based on social relationships and physical proximity. 6,746 samples were tested in 969 pools (average pool size 7.3 people) in a Washington, D.C. school, thereby requiring fewer test kits and less expense. The program was widely acceptable.3)What are the implications for public health practice?Pooling-in-a-pod allows for more accessible testing to facilitate safe in-person schooling and minimize the negative effects of distance learning.

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Testing for resistance: Point-of-care testing as a communicational tool in antibiotic prescribing

Communication & Medicine ◽

10.1558/cam.32191 ◽

2018 ◽

Vol 14 (3) ◽

pp. 229-240

Author(s):

Johanna Lindell

Keyword(s):

Point Of Care ◽

Rapid Test ◽

Antibiotic Use ◽

Treatment Recommendation ◽

Antibiotic Prescribing ◽

Communicative Practices ◽

Effective Strategies ◽

Reactive Protein ◽

Point Of Care Test ◽

Test Result

As antibiotic resistance becomes a growing health emergency, effective strategies are needed to reduce inappropriate antibiotic use. In this article, one such strategy – communicative practices associated with the C-reactive protein point-of care test – is investigated. Building on a collection of 31 videorecorded consultations from Danish primary care, and using conversation analysis, this study finds that the rapid test can be used throughout the consultation to incrementally build the case for a nonantibiotic treatment recommendation, both when the test result is forecast and reported. The study also finds that the format of reports of elevated results differs from that of ‘normal’ results, resulting in a subtle shift of authority from doctor to test.

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Aptamer-Based Diagnostic Systems for the Rapid Screening of TB at the Point-of-Care

Diagnostics ◽

10.3390/diagnostics11081352 ◽

2021 ◽

Vol 11 (8) ◽

pp. 1352

Author(s):

Darius Riziki Martin ◽

Nicole Remaliah Sibuyi ◽

Phumuzile Dube ◽

Adewale Oluwaseun Fadaka ◽

Ruben Cloete ◽

...

Keyword(s):

Low Income ◽

Point Of Care ◽

Health Care Systems ◽

Cost Effective ◽

Rapid Screening ◽

Low Income Countries ◽

Sputum Smear ◽

Diagnostic Systems ◽

Molecular Tests ◽

Rapid Tests

The transmission of Tuberculosis (TB) is very rapid and the burden it places on health care systems is felt globally. The effective management and prevention of this disease requires that it is detected early. Current TB diagnostic approaches, such as the culture, sputum smear, skin tuberculin, and molecular tests are time-consuming, and some are unaffordable for low-income countries. Rapid tests for disease biomarker detection are mostly based on immunological assays that use antibodies which are costly to produce, have low sensitivity and stability. Aptamers can replace antibodies in these diagnostic tests for the development of new rapid tests that are more cost effective; more stable at high temperatures and therefore have a better shelf life; do not have batch-to-batch variations, and thus more consistently bind to a specific target with similar or higher specificity and selectivity and are therefore more reliable. Advancements in TB research, in particular the application of proteomics to identify TB specific biomarkers, led to the identification of a number of biomarker proteins, that can be used to develop aptamer-based diagnostic assays able to screen individuals at the point-of-care (POC) more efficiently in resource-limited settings.

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Longitudinal remotely mentored self-performed lung ultrasound surveillance of paucisymptomatic Covid-19 patients at risk of disease progression

The Ultrasound Journal ◽

10.1186/s13089-021-00231-9 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Andrew W. Kirkpatrick ◽

Jessica L. McKee ◽

John M. Conly

Keyword(s):

At Risk ◽

Lung Ultrasound ◽

Point Of Care ◽

Human Life ◽

Vital Signs ◽

Home Monitoring ◽

Cost Effective ◽

Care Providers ◽

Vital Signs Monitoring ◽

Ultrasound Probes

AbstractCOVID-19 has impacted human life globally and threatens to overwhelm health-care resources. Infection rates are rapidly rising almost everywhere, and new approaches are required to both prevent transmission, but to also monitor and rescue infected and at-risk patients from severe complications. Point-of-care lung ultrasound has received intense attention as a cost-effective technology that can aid early diagnosis, triage, and longitudinal follow-up of lung health. Detecting pleural abnormalities in previously healthy lungs reveal the beginning of lung inflammation eventually requiring mechanical ventilation with sensitivities superior to chest radiographs or oxygen saturation monitoring. Using a paradigm first developed for space-medicine known as Remotely Telementored Self-Performed Ultrasound (RTSPUS), motivated patients with portable smartphone support ultrasound probes can be guided completely remotely by a remote lung imaging expert to longitudinally follow the health of their own lungs. Ultrasound probes can be couriered or even delivered by drone and can be easily sterilized or dedicated to one or a commonly exposed cohort of individuals. Using medical outreach supported by remote vital signs monitoring and lung ultrasound health surveillance would allow clinicians to follow and virtually lay hands upon many at-risk paucisymptomatic patients. Our initial experiences with such patients are presented, and we believe present a paradigm for an evolution in rich home-monitoring of the many patients expected to become infected and who threaten to overwhelm resources if they must all be assessed in person by at-risk care providers.

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N-protein presents early in blood, dried blood and saliva during asymptomatic and symptomatic SARS-CoV-2 infection

Nature Communications ◽

10.1038/s41467-021-22072-9 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Dandan Shan ◽

Joseph M. Johnson ◽

Syrena C. Fernandes ◽

Hannah Suib ◽

Soyoon Hwang ◽

...

Keyword(s):

Single Molecule ◽

High Performance ◽

Point Of Care ◽

Capillary Blood ◽

Molecular Testing ◽

Sample Collection ◽

Protein Assay ◽

N Protein ◽

Protein Levels ◽

Percent Agreement

AbstractThe COVID-19 pandemic continues to have an unprecedented impact on societies and economies worldwide. There remains an ongoing need for high-performance SARS-CoV-2 tests which may be broadly deployed for infection monitoring. Here we report a highly sensitive single molecule array (Simoa) immunoassay in development for detection of SARS-CoV-2 nucleocapsid protein (N-protein) in venous and capillary blood and saliva. In all matrices in the studies conducted to date we observe >98% negative percent agreement and >90% positive percent agreement with molecular testing for days 1–7 in symptomatic, asymptomatic, and pre-symptomatic PCR+ individuals. N-protein load decreases as anti-SARS-CoV-2 spike-IgG increases, and N-protein levels correlate with RT-PCR Ct-values in saliva, and between matched saliva and capillary blood samples. This Simoa SARS-CoV-2 N-protein assay effectively detects SARS-CoV-2 infection via measurement of antigen levels in blood or saliva, using non-invasive, swab-independent collection methods, offering potential for at home and point of care sample collection.

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