scholarly journals Rapid Antigen Test Combine with Nucleic Acid Detection: A Better Strategy for COVID-19 Screening at Points of Entry

2022 ◽  
Author(s):  
Zhiqing Zhan ◽  
Jie Li ◽  
Zhangkai J. Cheng
Keyword(s):  
Early Stage ◽  
High Sensitivity ◽  
High Viral Load ◽  
Nucleic Acid Detection ◽  
Rt Pcr ◽  
The Face ◽  
Polymerase Chain ◽  
Asymptomatic Infections ◽  
Post Entry ◽  
Antigen Tests

AbstractThe coronavirus disease 2019 (COVID-19) pandemic has imposed an enormous disease burden worldwide, and the Delta variant now has become dominant in 53 countries. Recently published studies have shown that during periods of high viral load, rapid antigen tests (RAT) yield similar results to reverse transcriptase-polymerase chain reaction (RT-PCR) tests, and when used in serial screening (e.g., every three days), it has a high sensitivity. In this perspective, we recommend RT-PCR combined with RAT at points of entry: (i) RAT can be added to the detection phase at ports of entry to detect asymptomatic infections as early as possible; (ii) RAT can be added to post-entry quarantine every three days or less to reduce the rate of missed detection in later quarantine; (iii) Adding regular RAT to regular PCR testing for key airport personnel to prevent cross-infection and conduct closed-off management. In the face of sporadic Delta variant outbreaks, the combination of the two could help rapid triage and management of suspected populations at an early stage and thus contain the outbreak more quickly and effectively. We also discuss the issue whether the current antigen detection reagents can cope with various SARS-CoV-2 variants.

scholarly journals High Sensitivity and NPV for BinaxNOW Rapid Antigen Test in Children at a Mass Testing Site During Prevalent Delta Variant

2022 ◽  
Author(s):  
Kristie J Sun ◽  
Mary Jane E Vaeth ◽  
Matthew L Robinson ◽  
Maryam Elhabashy ◽  
Ishaan Gupta ◽  
...  
Keyword(s):  
Predictive Value ◽  
High Sensitivity ◽  
High Volume ◽  
Educational Opportunities ◽  
Antigen Test ◽  
Sample Collection ◽  
Rt Pcr ◽  
Polymerase Chain ◽  
Testing Site ◽  
Antigen Tests

SARS-CoV-2 continues to develop new, increasingly infectious variants, such as delta and omicron. Here, we evaluate the efficacy of the Abbott BinaxNOW Rapid Antigen Test against the gold standard of Reverse Transcription Polymerase Chain Reaction (RT-PCR) in 1054 pediatric participants presenting to a state-owned high-volume Coronavirus Disease 2019 (COVID-19) testing site. During the testing period, the delta variant was predominant. Prior to sample collection, symptomatic and exposure status was collected for all participants based on Centers for Disease Control (CDC) criteria. RT-PCR results demonstrated an overall prevalence rate of 5.2%. For all participants, the sensitivity of the rapid antigen tests was 92.7% (95% CI 82.4% - 98.0%) and specificity was 98.0% (95% CI 97.0%-98.8%). For symptomatic participants, the sensitivity was 92.3% (95% CI 74.9% - 99.1%), specificity was 96.6% (95% CI 93.6%- 98.4%), positive predictive value (PPV) was 72.7% (95% CI 54.5% - 86.7%) and negative predictive value (NPV) was 99.2% (95% CI 98.2% - 100%). Among asymptomatic participants, the sensitivity was 92.6% (95% CI 75.7% - 99.1%), specificity was 98.6% (95% CI 97.5% - 99.3%) the PPV was 71.4% (95% CI 53.7% - 85.4%) and the NPV was 99.7% (95% CI 99.0% - 100%). Our reported sensitivity and NPV are higher than other pediatric studies, but specificity and PPV are lower. Importance Children are especially impacted by the disease and its ability to disrupt educational opportunities. Although vaccinations have been approved for children 5 years and older, many children remain unvaccinated. Widespread testing may improve the ability for children to remain in in-person activities, minimizing absences from school and extracurriculars. Highly accurate rapid antigen tests may be vital to containing future COVID-19 waves while mitigating detrimental effects.

scholarly journals Evaluation of the performance of the COVID-19 rapid antigen tests in a tertiary level hospital in Bangladesh.

2021 ◽  
Author(s):  
Mohammad Jahidur Rahman Khan ◽  
Md. Shahadat Hossain ◽  
Samshad Jahan Shumu ◽  
Md. Selim Reza ◽  
Farzana Mim ◽  
...  
Keyword(s):  
Viral Load ◽  
Real Time ◽  
Sensitivity And Specificity ◽  
Detection Rate ◽  
High Sensitivity ◽  
Rt Pcr ◽  
College Hospital ◽  
Medical College ◽  
Qrt Pcr ◽  
Antigen Tests

Abstract Background: While the COVID-19 pandemic is a worldwide crisis, tests with high sensitivity and specificity are essential for identifying and managing COVID-19 patients. Globally, several rapid antigen tests RATs for COVID-19 have been developed, but their clinical efficacy has not been well established. This study aimed to evaluate the performance of several rapid antigen tests (RATs) to diagnose SARS-CoV-2 infection.Methods: This prospective observational study was conducted at Shaheed Suhrawardy Medical College hospital from February 2021 to April 2021 in Dhaka, Bangladesh. This study included the patients admitted in this hospital at the COVID-19 isolation unit or referred from the triage facility of the outdoor department of this hospital suspected as COVID-19 case. Two nasopharyngeal samples were collected simultaneously. one sample was used on the spot for the RAT. The other was sent to the adjacent Shaheed Suhrawardy Medical College COVID-19 RT-PCR laboratory for real-time reverse transcription-polymerase chain reaction (qRT-PCR). The performance of the RAT was evaluated using the results of qRT-PCR as a reference.Results: A total of 223 patients were included in this study, and the real-time RT-PCR detected SARS-CoV-2 in 84 (37.7%) patients. Of these 84 patients, 9 (10.7%) were asymptomatic. The overall sensitivity and specificity of RATs were 78.6% and 99.3%, respectively. The sensitivity was 81.3% in symptomatic cases and 55.6% in asymptomatic cases. False-negatives were observed in 18 patients, 3 of whom were asymptomatic and had a low viral load (cycle threshold (Ct) > 30). The detection rate of RATs was 100% when the Ct value was up to 24. The detection rate was 42.3% when the Ct was >29. The detection rate of RATs was 92.3% when the onset of symptoms was within three days. The detection rate was 33.3% when the onset of symptoms was >7 days.Conclusions: RATs for COVID-19 used in this study delivered an acceptable performance in patients with high viral load and within the first week of the onset of symptoms. They can be used as a supplementary method to RT-PCR for the diagnosis of COVID-19 patients.

scholarly journals Prediction of the Spatial Origin of Puumala Virus Infections Using L Segment Sequences Derived from a Generic Screening PCR

Viruses ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 694 ◽  
Author(s):  
Weiss ◽  
Klempa ◽  
Tenner ◽  
Kruger ◽  
Hofmann
Keyword(s):  
Phylogenetic Signal ◽  
High Sensitivity ◽  
Puumala Virus ◽  
Virus Infections ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Polymerase Chain ◽  
L Segment ◽  
Virus Strains

To screen diagnostic specimens for the presence of hantavirus genomes or to identify new hantaviruses in nature, the pan-hanta L-PCR assay, a broadly reactive nested reverse transcription polymerase chain reaction (RT-PCR) assay targeting the L segment, is highly preferred over other assays because of its universality and high sensitivity. In contrast, the geographic allocation of Puumala virus strains to defined outbreak regions in Germany was previously done based on S segment sequences. We show that the routinely generated partial L segment sequences resulting from the pan-hanta L-PCR assay provide sufficient phylogenetic signal to inform the molecular epidemiology of the Puumala virus. Consequently, an additional S segment analysis seems no longer necessary for the identification of the spatial origin of a virus strain.

Prognostic Significance of Occult Metastases Detected by Sentinel Lymphadenectomy and Reverse Transcriptase–Polymerase Chain Reaction in Early-Stage Melanoma Patients

1999 ◽  
Vol 17 (10) ◽  
pp. 3238-3244 ◽  
Author(s):  
Peter J. Bostick ◽  
Donald L. Morton ◽  
Roderick R. Turner ◽  
Kelly T. Huynh ◽  
He-Jing Wang ◽  
...  
Keyword(s):  
Early Stage ◽  
Disease Relapse ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Sentinel Lymphadenectomy ◽  
Increased Risk ◽  
Melanoma Metastases ◽  
Melanoma Patients ◽  
Polymerase Chain ◽  
Mrna Markers

PURPOSE: Detection of micrometastases in the regional tumor-draining lymph nodes is critical for accurate staging and prognosis in melanoma patients. We hypothesized that a multiple-mRNA marker (MM) reverse transcriptase–polymerase chain reaction (RT-PCR) assay would improve the detection of occult metastases in the sentinel node (SN), compared with hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC), and that MM expression is predictive of disease relapse. PATIENTS AND METHODS: Seventy-two consecutive patients with clinical early-stage melanoma underwent sentinel lymphadenectomy (SLND). Their SNs were serially sectioned and assessed for MAGE-3, MART-1, and tyrosinase mRNA expression by RT-PCR, in parallel with H&E staining and IHC, for melanoma metastases. MM expression in the SNs was correlated with H&E and IHC assay results, standard prognostic factors, and disease-free survival. RESULTS: In 17 patients with H&E- and/or IHC-positive SNs, 16 (94%) expressed two or more mRNAmarkers. Twenty (36%) of 55 patients with histopathologically negative SNs expressed two or more mRNA markers. By multivariate analysis, patients at increased risk of metastases to the SN had thicker lesions (P = .03), were 60 years of age or younger (P < .05), and/or were MM-positive (P < .001). Patients with histopathologically melanoma-free SNs who were MM-positive, compared with those who were positive for one or fewer mRNA markers, were at increased risk of recurrence (P = .02). Patients who were MM-positive with histopathologically proven metastases in the SN were at greatest risk of disease relapse (P = .01). CONCLUSION: H&E staining and IHC underestimate the true incidence of melanoma metastases. MM expression in the SN more accurately reflects melanoma micrometastases and is also a more powerful predictor of disease relapse than are H&E staining and IHC alone.

scholarly journals A case of SARS-CoV-2 carrier for 32 days with several times false negative nucleic acid tests

2020 ◽  
Author(s):  
Lingjie Song ◽  
Guibao Xiao ◽  
Xianqin Zhang ◽  
Zhan Gao ◽  
Shixia Sun ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Clinical Symptoms ◽  
Early Stage ◽  
Antiviral Treatment ◽  
Immune Therapy ◽  
False Negative ◽  
Clinical Manifestations ◽  
Nucleic Acid Detection ◽  
Rt Pcr ◽  
Nucleic Acid Tests

AbstractIn 2019, a novel coronavirus (SARS-CoV-2) was first discovered in Wuhan, Hubei, China, causing severe respiratory disease in humans, and has been identified as a public health emergency of international concern. With the spread of the virus, there are more and more false negative cases of RT-PCR nucleic acid detection in the early stage of potential infection. In this paper, we collected the epidemiological history, clinical manifestations, outcomes, laboratory results and images of a SARS-CoV-2 carrier with no significant past medical history. The patient was quarantined because of her colleague had been diagnosed. After the onset of clinical symptoms, chest CT results showed patchy ground-glass opacity (GGO) in her lungs, but it took a total of nine nucleic acid tests to confirm the diagnosis, among which the first eight RT-PCR results were negative or single-target positive. In addition to coughing up phlegm during her stay in the hospital, she did not develop chills, fever, abdominal pain, diarrhea and other clinical symptoms. Since initial antiviral treatment, the lung lesions were absorbed. But the sputum nucleic acid test was still positive. In combination with antiviral and immune therapy, the patient tested negative for the virus. Notably, SARS-CoV-2 was detected only in the lower respiratory tract samples (sputum) throughout the diagnosis and treatment period. This is a confirmed case of SARS-CoV-2 infection with common symptoms, and her diagnosis has undergone multiple false negatives, suggesting that it is difficult to identify certain carriers of the virus and that such patients may also increase the spread of the SARS-CoV-2.

scholarly journals The accuracy of saliva versus nasopharyngeal and/or oropharyngeal samples for the detection of SARS-CoV-2 in children. A rapid systematic review and meta-analysis

2021 ◽  
Author(s):  
Sharonjit Kaur Dhillon ◽  
Petra Schelstraete ◽  
Laura Cornelissen ◽  
Yves Lafort ◽  
Jesper Bonde ◽  
...  
Keyword(s):  
Meta Analysis ◽  
High Viral Load ◽  
Reference Standard ◽  
Rt Pcr ◽  
Comparative Performance ◽  
Additional Information ◽  
Asymptomatic Children ◽  
Comparable Performance ◽  
Polymerase Chain ◽  
Meta Analyses

Background The comparative performance of saliva and nasopharyngeal samples for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by reverse transcriptase polymerase chain reaction (RT-PCR) in children remains unclear. As schools reopen around the world, there is an interest in the use of saliva samples for detection of SARS-CoV-2 in children to circumvent barriers with nasopharyngeal sampling. We systematically reviewed the literature to understand the performance of saliva sampling using RT-PCR on naso- and/or oropharyngeal swabs as the reference standard. Methods Articles from PubMed/MEDLINE and Living Evidence were accessed until 28th April 2021. A search method without restriction to children population was applied and during the review phase, if a study included patients <18 years old, authors were contacted to provide additional information on the subset of children. Studies were eligible if they reported on matched saliva and naso- and/or oropharyngeal samples, taken from the same patient on the same day. Studies using other respiratory samples such as sputum samples were excluded. Each paired patient sample had to be tested on the same RT-PCR platform. Results Ten studies were included, comprising 1486 matched saliva and on naso- and/or oropharyngeal pairs from children aged 0 to 18 years old. The pooled absolute sensitivity and specificity of saliva sampling using RT-PCR on nasopharyngeal samples as the reference standard was 84.5% (95% CI; 78.0%-90.3%) and 99.5% (95% CI; 98.2%-100.0%). Comparable performance of saliva to nasopharyngeal samples was shown in both symptomatic and asymptomatic children. Stratified analyses of various covariates showed no significant differences. Discussion Our pooled accuracy estimates of RT-PCR SARS-CoV-2 testing on saliva in children did not seem to be different from meta-analyses of studies that enrolled mainly adults. Saliva could potentially be considered an alternative sampling method for screening in children and to pick up those with high viral load.

SARS-CoV-2 in spent dialysate from chronic peritoneal dialysis patients with COVID-19

Kidney360 ◽  
2020 ◽  
pp. 10.34067/KID.0006102020
Author(s):  
Xiaoling Wang ◽  
Amrish Patel ◽  
Lela Tisdale ◽  
Zahin Haq ◽  
Xiaoling Ye ◽  
...  
Keyword(s):  
Peritoneal Dialysis ◽  
Nasal Swab ◽  
Early Stage ◽  
Acid Extraction ◽  
Rt Pcr ◽  
Bacteriophage Ms2 ◽  
Spent Dialysate ◽  
Polymerase Chain ◽  
Genomic Regions ◽  
Rule Out

Background To date it is unclear whether SARS-CoV-2 is present in spent dialysate from peritoneal dialysis (PD) patients with COVID-19. Our aim was to assess the presence or absence of SARS-CoV-2 in spent dialysate from chronic PD patients with confirmed diagnosis of COVID-19. Methods Spent PD dialysate samples from COVID-19 positive PD patients were collected between March and August 2020. The multiplexed real-time reverse transcriptase-polymerase chain reaction assay contained primer/probe sets specific to different SARS-CoV-2 genomic regions and to bacteriophage MS2 as internal process control for nucleic acid extraction. Demographic and clinical data were obtained from patients' electronic health records. Results A total of 26 spent PD dialysate samples were collected from 11 patients from 10 dialysis centers. Spent PD dialysate samples were collected on average 25±13 days (median 20, range 10 to 45) after onset of symptoms. The temporal distance of PD effluent collection relative to the closest positive nasal swab RT PCR was 15±11 days (median 14; range 1 to 41). All 26 PD effluent samples tested negative at three SARS-CoV-2 genomic regions. Conclusions Our findings indicate the absence of SARS-CoV-2 in spent PD dialysate collected 10 days or later after the onset of COVID-19 symptoms. We cannot rule out presence of SARS-CoV-2 in spent PD dialysate in the early stage of COVID-19.

Interlaboratory Evaluation of a New Reverse Transcriptase Polymerase Chain Reaction–Based Enzyme-Linked Immunosorbent Assay for the Detection of Circulating Melanoma Cells: A Multicenter Study of the Dermatologic Cooperative Oncology Group

2001 ◽  
Vol 19 (6) ◽  
pp. 1723-1727 ◽  
Author(s):  
U. Reinhold ◽  
C. Berkin ◽  
A.-K. Bosserhoff ◽  
A. Deutschmann ◽  
C. Garbe ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Tumor Cells ◽  
High Sensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Blood Samples ◽  
Melanoma Patients ◽  
Polymerase Chain ◽  
Interlaboratory Reproducibility

PURPOSE: Reverse transcription-polymerase chain reaction (RT-PCR)–based detection of tyrosinase mRNA is the most frequently used laboratory method for the detection of circulating tumor cells in melanoma patients. However, previously published results showed considerable variability in the PCR positivity rates. MATERIALS AND METHODS: We designed a collaborative study to assess the sensitivity, specificity, and clinical relevance of a new standardized RT-PCR–based enzyme-linked immunosorbent assay (ELISA) for the detection of circulating melanoma cells. Blood samples of healthy donors mixed with cells of a melanoma cell line were prepared in a blinded fashion, and aliquots were sent to seven participating laboratories experienced in RT-PCR. RESULTS: The results demonstrate a high sensitivity (1 melanoma cell/mL blood) and specificity (no false-negatives and 7.4% [2 of 28] false-positives) of the assay and a satisfactory rate of interlaboratory reproducibility. The analysis of aliquots of blinded samples derived from 60 melanoma patients identified tyrosinase mRNA in 17 of 60 (28.3%): three (20%) of 15 stage I patients, two (13.3%) of 15 stage II patients, five (35.7%) of 14 stage III patients, and seven (43.8%) of 16 stage IV patients. The interlaboratory reproducibility of positive samples, however, was extremely low and indicates the presence of low amounts of target mRNA. CONCLUSION: Reverse transcriptase-PCR ELISA has a high sensitivity and specificity for the detection of tyrosinase mRNA in peripheral blood cells. The low interlaboratory reproducibility for the detection of tumor cells in blood samples of melanoma patients, however, raises the question of relevance of this assay for clinical use.

scholarly journals Evaluation of Nucleocapsid and Spike Protein-Based Enzyme-Linked Immunosorbent Assays for Detecting Antibodies against SARS-CoV-2

2020 ◽  
Vol 58 (6) ◽  
Author(s):  
Wanbing Liu ◽  
Lei Liu ◽  
Guomei Kou ◽  
Yaqiong Zheng ◽  
Yinjuan Ding ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Early Stage ◽  
Disease Onset ◽  
High Sensitivity ◽  
Spike Protein ◽  
Nucleic Acid Detection ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Positive Rate

ABSTRACT At present, PCR-based nucleic acid detection cannot meet the demands for coronavirus infectious disease (COVID-19) diagnosis. Two hundred fourteen confirmed COVID-19 patients who were hospitalized in the General Hospital of Central Theater Command of the People’s Liberation Army between 18 January and 26 February 2020 were recruited. Two enzyme-linked immunosorbent assay (ELISA) kits based on recombinant severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleocapsid protein (rN) and spike protein (rS) were used for detecting IgM and IgG antibodies, and their diagnostic feasibility was evaluated. Among the 214 patients, 146 (68.2%) and 150 (70.1%) were successfully diagnosed with the rN-based IgM and IgG ELISAs, respectively; 165 (77.1%) and 159 (74.3%) were successfully diagnosed with the rS-based IgM and IgG ELISAs, respectively. The positive rates of the rN-based and rS-based ELISAs for antibody (IgM and/or IgG) detection were 80.4% and 82.2%, respectively. The sensitivity of the rS-based ELISA for IgM detection was significantly higher than that of the rN-based ELISA. We observed an increase in the positive rate for IgM and IgG with an increasing number of days post-disease onset (d.p.o.), but the positive rate of IgM dropped after 35 d.p.o. The positive rate of rN-based and rS-based IgM and IgG ELISAs was less than 60% during the early stage of the illness, 0 to 10 d.p.o., and that of IgM and IgG was obviously increased after 10 d.p.o. ELISA has a high sensitivity, especially for the detection of serum samples from patients after 10 d.p.o., so it could be an important supplementary method for COVID-19 diagnosis.

scholarly journals Conidiophore Stalk-less1 Encodes a Putative Zinc-Finger Protein Involved in the Early Stage of Conidiation and Mycelial Infection in Magnaporthe oryzae

2009 ◽  
Vol 22 (4) ◽  
pp. 402-410 ◽  
Author(s):  
Zhuangzhi Zhou ◽  
Guihua Li ◽  
Chunhua Lin ◽  
Chaozu He
Keyword(s):  
Zinc Finger ◽  
Magnaporthe Oryzae ◽  
Wild Type Strain ◽  
Zinc Finger Protein ◽  
Early Stage ◽  
Host Cells ◽  
Rt Pcr ◽  
Finger Protein ◽  
Polymerase Chain ◽  
Putative Zinc Finger

Over recent decades, many pathogenicity genes of Magnaporthe oryzae have been identified but only a very limited number of genes have been identified that encode components of the conidiogenesis pathway. We report here a T-DNA insertional mutant that completely lost conidiation ability. Further investigation revealed that this mutant did not develop any conidiophore, and that the T-DNA was integrated into an annotated gene designated as conidiophore stalk-less1 or COS1. Complementation experiments suggested that COS1 may be a determinant of conidiation. Sequence analysis revealed that COS1 putatively encodes a 491-amino-acid zinc-finger protein and the protein was revealed localized to nucleus. Reverse-transcriptase polymerase chain reaction (RT-PCR)-based expression analysis indicated that two homologues of conidiophore-related genes were affected by the cos1 mutation, suggesting that Cos1 may function as a transcriptional regulator controlling genes responsible for conidiation. Inoculations of rice roots and wounded leaves with mycelia suggested that COS1 is not required for pathogenicity. Moreover, mutation of COS1 may aggravate infection of wounded leaves. Interestingly, different from the wild-type strain, mycelia of the cos1 mutant successfully infected host cells and caused visible symptoms on unwounded leaf blades and sheaths, indicating that Cos1 may have a role in some unknown mechanism of mycelial infection of M. oryzae.

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