scholarly journals Evaluation of COVID-19 RT-qPCR Test in Multi sample Pools

2020 ◽  
Vol 71 (16) ◽  
pp. 2073-2078 ◽  
Author(s):  
Idan Yelin ◽  
Noga Aharony ◽  
Einat Shaer Tamar ◽  
Amir Argoetti ◽  
Esther Messer ◽  
...  
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
False Negative ◽  
Rna Extraction ◽  
False Negative Rate ◽  
Positive Sample ◽  
Recent Emergence ◽  
Single Positive ◽  
Polymerase Chain ◽  
Pool Test ◽  
Current Screening

Abstract Background The recent emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) led to a current pandemic of unprecedented scale. Although diagnostic tests are fundamental to the ability to detect and respond, overwhelmed healthcare systems are already experiencing shortages of reagents associated with this test, calling for a lean immediately applicable protocol. Methods RNA extracts of positive samples were tested for the presence of SARS-CoV-2 using reverse transcription quantitative polymerase chain reaction, alone or in pools of different sizes (2-, 4-, 8-, 16-, 32-, and 64-sample pools) with negative samples. Transport media of additional 3 positive samples were also tested when mixed with transport media of negative samples in pools of 8. Results A single positive sample can be detected in pools of up to 32 samples, using the standard kits and protocols, with an estimated false negative rate of 10%. Detection of positive samples diluted in even up to 64 samples may also be attainable, although this may require additional amplification cycles. Single positive samples can be detected when pooling either after or prior to RNA extraction. Conclusions As it uses the standard protocols, reagents, and equipment, this pooling method can be applied immediately in current clinical testing laboratories. We hope that such implementation of a pool test for coronavirus disease 2019 would allow expanding current screening capacities, thereby enabling the expansion of detection in the community, as well as in close organic groups, such as hospital departments, army units, or factory shifts.

scholarly journals Evaluation of COVID-19 RT-qPCR test in multi-sample pools

2020 ◽  
Author(s):  
Idan Yelin ◽  
Noga Aharony ◽  
Einat Shaer Tamar ◽  
Amir Argoetti ◽  
Esther Messer ◽  
...  
Keyword(s):  
Diagnostic Tests ◽  
False Negative ◽  
False Negative Rate ◽  
Positive Sample ◽  
Testing Laboratories ◽  
Recent Emergence ◽  
Single Positive ◽  
Pool Test ◽  
Current Screening ◽  
A Current

AbstractThe recent emergence of SARS-CoV-2 lead to a current pandemic of unprecedented levels. Though diagnostic tests are fundamental to the ability to detect and respond, many health systems are already experiencing shortages of reagents associated with this test. Here, testing a pooling approach for the standard RT-qPCR test, we find that a single positive sample can be detected even in pools of up to 32 samples, with an estimated false negative rate of 10%. Detection of positive samples diluted in even up to 64 samples may also be attainable, though may require additional amplification cycles. As it uses the standard protocols, reagents and equipment, this pooling method can be applied immediately in current clinical testing laboratories. We hope that such implementation of a pool test for COVID-19 would allow expanding current screening capacities thereby enabling the expansion of detection in the community, as well as in close integral groups, such as hospital departments, army units, or factory shifts.

scholarly journals Pooling of Upper Respiratory Specimens Using a SARS-CoV-2 Real-time RT-PCR Assay Authorized for Emergency Use in Low-Prevalence Populations for High-Throughput Testing

2020 ◽  
Vol 7 (11) ◽  
Author(s):  
Gwynngelle A Borillo ◽  
Ron M Kagan ◽  
Russell E Baumann ◽  
Boris M Fainstein ◽  
Lamela Umaru ◽  
...  
Keyword(s):  
Real Time ◽  
False Negative ◽  
False Negative Rate ◽  
Nucleic Acid Amplification ◽  
Rt Pcr ◽  
Pooled Testing ◽  
Negative Results ◽  
Single Positive ◽  
Upper Respiratory ◽  
Respiratory Specimens

Abstract Background Nucleic acid amplification testing is a critical tool for addressing the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Specimen pooling can increase throughput and conserve testing resources but requires validation to ensure that reduced sensitivity does not increase the false-negative rate. We evaluated the performance of a real-time reverse transcription polymerase chain reaction (RT-PCR) test authorized by the US Food and Drug Administration (FDA) for emergency use for pooled testing of upper respiratory specimens. Methods Positive specimens were selected from 3 prevalence groups, 1%–3%, >3%–6%, and >6%–10%. Positive percent agreement (PPA) was assessed by pooling single-positive specimens with 3 negative specimens; performance was assessed using Passing-Bablok regression. Additionally, we assessed the distributions of RT-PCR cycle threshold (Ct) values for 3091 positive specimens. Results PPA was 100% for the 101 pooled specimens. There was a linear relationship between Ct values for pooled and single-tested specimens (r = 0.96–0.99; slope ≈ 1). The mean pooled Ct shifts at 40 cycles were 2.38 and 1.90, respectively, for the N1 and N3 targets. The median Cts for 3091 positive specimens were 25.9 (N1) and 24.7 (N3). The percentage of positive specimens with Cts between 40 and the shifted Ct was 1.42% (N1) and 0.0% (N3). Conclusions Pooled and individual testing of specimens positive for SARS-CoV-2 demonstrated 100% agreement, which demonstrates the viability of pooled specimens for SARS-COV-2 testing using a dual-target RT-PCR system. Pooled specimen testing can help increase testing capacity for SARS-CoV-2 with a low risk of false-negative results.

scholarly journals Pooled Testing for Expanding COVID-19 Mass Surveillance

2020 ◽  
Vol 14 (3) ◽  
pp. e42-e43 ◽  
Author(s):  
Angela Felicia Sunjaya ◽  
Anthony Paulo Sunjaya
Keyword(s):  
Diagnostic Testing ◽  
Pcr Amplification ◽  
The United States ◽  
Positive Sample ◽  
Pooled Testing ◽  
Blood Banks ◽  
Massive Scale ◽  
Polymerase Chain ◽  
Pool Test ◽  
Mass Surveillance

ABSTRACTDiagnostic testing to identify patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) plays a key role to control the coronavirus disease (COVID-19) pandemic. While several countries have implemented the use of diagnostic testing in a massive scale as a cornerstone for infection control and surveillance, other countries affected by the pandemic are hampered by its limited testing capacity. Pooled testing was first introduced in the 1940s and is now used for screening in blood banks. Testing is done by pooling multiple individual samples together. Only in the case of a positive pool test would individual samples of the pool be tested, thus substantially reducing the number of tests needed. Several studies regarding their use for SARS CoV-2 have been done in the United States, Israel, and Germany. Studies have shown that an individual positive sample can still be detected in pools of up to 32 samples, and possibly even 64 samples, provided that additional polymerase chain reaction (PCR) amplification cycles are conducted with a sensitivity of 96%. Simulation studies to determine optimal pool size and pooling techniques have also been conducted. Based on these studies, pooled testing is shown to be able to detect positive samples with sufficient accuracy and can easily be used with existing equipment and personnel for population-wide screening.

scholarly journals COVID-19 automatic diagnosis with CT images using the novel Transformer architecture

2021 ◽  
Author(s):  
Gabriel Sousa Silva Costa ◽  
Anselmo C. Paiva ◽  
Geraldo Braz Júnior ◽  
Marco Melo Ferreira
Keyword(s):  
Intelligent System ◽  
State Of The Art ◽  
False Negative ◽  
False Negative Rate ◽  
Ct Images ◽  
The Novel ◽  
Chain Reaction ◽  
High False Negative Rate ◽  
Polymerase Chain ◽  
Low Sensitivity

Even though vaccines are already in use worldwide, the COVID-19 pandemic is far from over, with some countries re-establishing the lockdown state, the virus has taken over 2 million lives until today, being a serious health issue. Although real-time reverse transcription-polymerase chain reaction (RTPCR) is the first tool for COVID-19 diagnosis, its high false-negative rate and low sensitivity might delay accurate diagnosis. Therefore, fast COVID-19 diagnosis and quarantine, combined with effective vaccination plans, is crucial for the pandemic to be over as soon as possible. To that end, we propose an intelligent system to classify computed tomography (CT) of lung images between a normal, pneumonia caused by something other than the coronavirus or pneumonia caused by the coronavirus. This paper aims to evaluate a complete selfattention mechanism with a Transformer network to capture COVID-19 pattern over CT images. This approach has reached the state-of-the-art in multiple NLP problems and just recently is being applied for computer vision tasks. We combine vision transformer and performer (linear attention transformers), and also a modified vision transformer, reaching 96.00% accuracy.

scholarly journals Investigation of pooling strategies using clinical COVID-19 samples for more efficient diagnostic testing

2020 ◽  
Author(s):  
Samantha H Adikari ◽  
Emily Z Alipio Lyon ◽  
Attelia D Hollander ◽  
Alina Deshpande ◽  
Elizabeth Hong-Geller
Keyword(s):  
Diagnostic Testing ◽  
Rna Extraction ◽  
Positive Sample ◽  
Viral Rna ◽  
Clinical Samples ◽  
Extraction Column ◽  
Diagnostic Assay ◽  
Significant Difference ◽  
Pooling Strategies ◽  
Single Positive

When testing large numbers of clinical COVID-19 samples for diagnostic purposes, pooling samples together for processing can offer significant reductions in the materials, reagents, time, and labor needed. We have evaluated two different strategies for pooling independent nasopharyngeal swab samples prior to testing with an EUA-approved SARS-CoV-2 RT-qPCR diagnostic assay. First, in the Dilution Study, we assessed the assay's ability to detect a single positive clinical sample diluted in multiple negative samples before the viral RNA extraction stage. We observed that positive samples with Ct values at ~30 can be reliably detected in pools of up to 30 independent samples, and positive samples with Ct values at ~35 can be detected in pools of 5 samples. Second, in the Reloading Study, we assessed the efficacy of reloading QIAamp viral RNA extraction columns numerous times using a single positive sample and multiple negative samples. We determined that one RNA extraction column can be reloaded with up to 20 clinical samples (1 positive and 19 negatives) sequentially without any loss of signal in the diagnostic assay. Furthermore, we found there was no significant difference in assay readout whether the positive sample was loaded first or last in a series of 20 samples. These results demonstrate that different pooling strategies can lead to increased process efficiencies for COVID-19 clinical diagnostic testing.

High False-Negative Rate of HER2 Quantitative Reverse Transcription Polymerase Chain Reaction of the Oncotype DX Test: An Independent Quality Assurance Study

2011 ◽  
Vol 29 (32) ◽  
pp. 4279-4285 ◽  
Author(s):  
David J. Dabbs ◽  
Molly E. Klein ◽  
Syed K. Mohsin ◽  
Raymond R. Tubbs ◽  
Yongli Shuai ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Quality Assurance ◽  
Reverse Transcription ◽  
False Negative ◽  
False Negative Rate ◽  
Oncotype Dx ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Negative Rate ◽  
Polymerase Chain

Purpose HER2 (ERBB2) status is an important prognostic and predictive marker in breast carcinoma. In recent years, Genomic Health (GHI), purveyors of the Oncotype DX test, has been separately reporting HER2 by reverse transcription polymerase chain reaction (RT-PCR) to oncologists. Because of the lack of independent evaluation, this quality assurance study was undertaken to define the concordance rate between immunohistochemistry (IHC)/fluorescent in situ hybridization (FISH) and GHI RT-PCR HER2 assay. Methods All patients at three participating laboratories (Magee-Womens Hospital [Pittsburgh, PA], Cleveland Clinic [Cleveland, OH], and Riverside Methodist Hospital [Columbus, OH]) with available HER2 RT-PCR results from GHI were included in this study. All IHC-positive and equivocal patient cases were further evaluated and classified by FISH at respective laboratories. Results Of the total 843 patient cases, 784 (93%) were classified as negative, 36 (4%) as positive, and 23 (3%) as equivocal at the three institutions using IHC/FISH. Of the 784 negative patient cases, 779 (99%) were also classified as negative by GHI RT-PCR assay. However, all 23 equivocal patient cases were reported as negative by GHI. Of the 36 positive cases, only 10 (28%; 95% CI, 14% to 45%) were reported as positive, 12 (33%) as equivocal, and 14 (39%) as negative. Conclusion There was an unacceptable false-negative rate for HER2 status with GHI HER2 assay in this independent study. This could create confusion in the decision-making process for targeted treatment and potentially lead to mismanagement of patients with breast cancer if only GHI HER2 information is used.

scholarly journals Flocked swab might be one main reason causing the high false-negative rate in COVID-19 screening----the advantages of a novel silicone swab

2020 ◽  
Author(s):  
Jianye Zhou ◽  
Zhongtian Bai ◽  
Xiaoping Liu ◽  
Yaqiong Guo ◽  
Nan Jiang ◽  
...  
Keyword(s):  
False Negative ◽  
Rna Extraction ◽  
False Negative Rate ◽  
Principal Component ◽  
Human Society ◽  
Sample Collection ◽  
Cotton Swab ◽  
High False Negative Rate ◽  
Rna Concentration

SummaryRNA testing using RT-PCR can provide direct evidence for diagnoses of COVID-19 which has brought unexpected disasters and changes to our human society. However, the absorption of cotton swab for RNA lysates may lead to a low concentration of detectable RNA, which might be one of the main reasons for the unstable positive detecting rate. We designed and manufactured a kind of silicone swab with concave-convex structure, and further compared the effects of silicone and cotton swab on RNA extraction. Principal component analysis and Paired Wilcoxcon test suggested that a higher RNA concentration and A260/A280 would be obtained using silicone swab. The results indicated that our silicone swab had a more excellent ability to sample than the cotton swab, characterized by the higher quantity and quality of extracted RNA. Thus, we advised that the current cotton swabs need to be improved urgently in COVID-19 diagnoses and the process of “sample collection” and “sample pre-processing” must be standardized and emphasized.HighlightsThe current cotton swabs need to be improved urgently in COVID-19 screening.

scholarly journals Variation in False-Negative Rate of Reverse Transcriptase Polymerase Chain Reaction–Based SARS-CoV-2 Tests by Time Since Exposure

2020 ◽  
Vol 173 (4) ◽  
pp. 262-267 ◽  
Author(s):  
Lauren M. Kucirka ◽  
Stephen A. Lauer ◽  
Oliver Laeyendecker ◽  
Denali Boon ◽  
Justin Lessler
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcriptase ◽  
False Negative ◽  
False Negative Rate ◽  
Chain Reaction ◽  
Negative Rate ◽  
Polymerase Chain
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