scholarly journals New Insight into Laboratory Tests and Imaging Modalities for Fast and Accurate Diagnosis of COVID-19: Alternative Suggestions for Routine RT-PCR and CT—A Literature Review

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Amir Khorasani ◽  
Amir Chegini ◽  
Arezoo Mirzaei
Keyword(s):  
False Negative ◽  
Imaging Modalities ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain ◽  
Magnetic Resonance Imaging Mri ◽  
Insight Into

The globally inimitable and unremitting outbreak of COVID-19 infection confirmed the emergency need for critical detection of human coronavirus infections. Laboratory diagnostic tests and imaging modalities are two test groups used for the detection of COVID-19. Nowadays, real-time polymerase chain reaction (RT-PCR) and computed tomography (CT) have been frequently utilized in the clinic. Some limitations that confront with these tests are false-negative results, tests redone for follow-up procedure, high cost, and unable to do for all patients. To overcome these limitations, modified and alternative tests must be considered. Among these tests, RdRp/Hel RT-PCR assay had the lowest diagnostic limitation and highest sensitivity and specificity for the detection of SARS-CoV-2 RNA in both respiratory tract and nonrespiratory tract clinical specimens. On the other hand, lung ultrasound (LUS) and magnetic resonance imaging (MRI) are CT-alternative imaging modalities for the management, screening, and follow-up of COVID-19 patients.

Scoring System for the Diagnosis of COVID-19

2020 ◽  
Vol 13 (1) ◽  
pp. 413-414 ◽  
Author(s):  
Mohamed Farouk Allam
Keyword(s):  
Scoring System ◽  
Clinical Symptoms ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Negative Results ◽  
False Negative Results ◽  
Symptoms And Signs

Due to the international spread of COVID-19, the difficulty of collecting nasopharyngeal swab specimen from all suspected patients, the costs of RT-PCR and CT, and the false negative results of RT-PCR assay in 41% of COVID-19 patients, a scoring system is needed to classify the suspected patients in order to determine the need for follow-up, home isolation, quarantine or the conduction of further investigations. A scoring system is proposed as a diagnostic tool for suspected patients. It includes Epidemiological Evidence of Exposure, Clinical Symptoms and Signs, and Investigations (if available). This scoring system is simple, could be calculated in a few minutes, and incorporates the main possible data/findings of any patient.

scholarly journals Diagnosis of COVID-19 by Serology in Admitted Patients with Negative RT-PCR Assay

2021 ◽  
Author(s):  
Mitra Rezaei ◽  
Parvaneh Baghaei ◽  
Makan Sadr ◽  
Afshin Moniri ◽  
Abdolreza Babamahmoodi ◽  
...  
Keyword(s):  
Diagnostic Yield ◽  
Serological Test ◽  
False Negative ◽  
Diagnostic Methods ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Serological Tests ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain

Considering the increasing prevalence and burden of coronavirus disease 2019 (COVID-19) disease and false-negative results in routine reverse transcription-polymerase chain reaction (RT-PCR) tests, additional diagnostic methods are needed to diagnose active cases of this disease. This prospective study was conducted on patients, in whom clinical and radiological symptoms/signs were in favor of COVID-19 while their first PCR test was negative. Later on, a second RT-PCR was performed and serological evaluation was carried out and results were compared with each other. Out of 707 patients who had been referred to the hospital and were clinically and radiologically suspicious of disease, 137 patients with negative RT-PCR tests entered the study. RT-PCR assay became positive for the second time in 45 (32.8%). Anti-COVID-19 IgM and IgG antibodies were positive in 83 (60.6%) and 86 (62.8%) patients, respectively. Finally, it was determined that serological test was diagnostic in 73% of patients and the diagnostic yield of serology was significantly higher after the first week of illness (54.8% in the first week and 88% after that). Taking advantage of both serological tests and RT-PCR helps in diagnosing 83.9% of cases. Based on the present study, the serology may be useful as a complementary test and in parallel to RT-PCR assay for diagnosis of COVID-19 among admitted symptomatic cases.

scholarly journals Reducing False Negative PCR Test for COVID-19

2020 ◽  
Vol 9 (3) ◽  
pp. 408-410
Author(s):  
Fatemeh Bahreini ◽  
Rezvan Najafi ◽  
Razieh Amini ◽  
Salman Khazaei ◽  
Saeid Bashirian
Keyword(s):  
Polymerase Chain Reaction ◽  
Real Time ◽  
False Negative ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Creative Commons ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain ◽  
Pcr Test

As the SARS-CoV-2 (COVID-19) pandemic spreads rapidly, there is need for a diagnostic test with high accuracy to detect infected individuals especially those without symptoms. Real-time polymerase chain reaction (RT-PCR) is a common molecular test for diagnosing SARS-CoV-2. If some factors are not taken into consideration when performing this test, it can have a relatively large number of false negative results. In this article, we discuss important considerations that could lead to false negative test reduction. Key words: • SARS-CoV-2 • COVID-19 • Real time polymerase chain reaction • RT-PCR test • Diagnosis • False negatives • Genetics • Emerging disease   Copyright © 2020 Bahreini et al. Published by Global Health and Education Projects, Inc. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0)which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in this journal, is properly cited.

scholarly journals False-Negative Nasopharyngeal Swab RT-PCR Assays in Typical COVID-19: Role of Ultra-low-dose Chest CT and Bronchoscopy in Diagnosis

2020 ◽  
Author(s):  
Marco Marando ◽  
Adriana Tamburello ◽  
Pietro Gianella
Keyword(s):  
Low Dose ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Oral Swab ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain ◽  
Pcr Assays

On 11 March 2020, the WHO declared COVID-19 a pandemic and global health emergency. We describe the clinical features and role of ultra-low-dose chest computed tomography (CT) and bronchoscopy in the diagnosis of coronavirus disease (COVID-19). In our patient, who was highly suggestive clinically and radiologically for COVID-19, we had two false-negative results for nasopharyngeal and oral swab reverse-transcriptase polymerase chain reaction (RT-PCR) assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Eventually, we confirmed the diagnosis using bronchoscopy and bronchoalveolar lavage (BAL).

scholarly journals Impact of false negative results of RT-PCR test for SARS-CoV-2 in COVID-19 case count as applied to Mexico

2020 ◽  
Author(s):  
Isaac J. Núñez ◽  
Pablo F. Belaunzarán-Zamudio ◽  
Yanink Caro-Vega
Keyword(s):  
False Negative ◽  
Open Data ◽  
Clinical Samples ◽  
Rt Pcr ◽  
Negative Results ◽  
Case Count ◽  
False Negative Results ◽  
True Number ◽  
High Prevalence ◽  
Polymerase Chain

Underestimation of the number of cases during the COVID-19 pandemic has been a constant concern worldwide. Case confirmation is based on identification of SARS-CoV-2 RNA using real time polymerase chain reaction (RT-PCR) in clinical samples. However, these tests have suboptimal sensitivity, especially during the early and late course of infection. Using open data, we estimated that among 1 343 730 people tested in Mexico since February 27th, there were 838 377 (95% CL 734 605 - 1 057 164) cases, compared with 604 376 considering only positive tests. ICU admissions and deaths were around 16% and 9% higher than reported. Thus, we show that accounting for the sensitivity of SARS-Cov-2 RT-PCR diagnostic tests is a simple way to improve estimations for the true number of COVID-19 cases in tested people, particularly in high-prevalence populations. This could aid to better inform public health measures and reopening policies.

Development of a Polymerase Chain Reaction Assay for Detection of Burkholderia mallei, a Potent Biological Warfare Agent

2016 ◽  
Vol 66 (5) ◽  
pp. 458 ◽  
Author(s):  
Vijai Pal ◽  
Sandeep Singh ◽  
Arvind Kumar Tiwari ◽  
Y.K. Jaiswal ◽  
G.P. Rai
Keyword(s):  
Polymerase Chain Reaction ◽  
Tap Water ◽  
False Negative ◽  
Burkholderia Mallei ◽  
Chain Reaction ◽  
Pcr Assay ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain ◽  
Rapid Tool

Burkholderia mallei is the etiological agent of glanders, primarily a disease of equines. B. mallei is closely related to B. pseudomallei, the causative agent of melioidosis. Therefore, detection of B. mallei and its differentiation from B. pseudomallei, has always been troublesome. In present investigation, a B. mallei specific DNA sequence was identified by performing BLASTn search using ~3000 ORFs of B. mallei NCTC 10229. A polymerase chain reaction (PCR) assay with internal amplification control (IAC) was developed for detection of B. mallei and its differentiation from B. pseudomallei. The PCR assay could amplify a specific 224-bp fragment from all the six B. mallei strains used in the study, whereas other closely related organisms were tested negative. The detection limit of the assay was found to be 10 pg of purified DNA of B. mallei. Incorporation of IAC in the assay makes the results reliable as false negative results which may arise due to presence of PCR inhibitors, can be avoided. For validation, the assay was tested on tap water, Bengal gram and grass artificially spiked with B. mallei. The developed assay can be used as a simple and rapid tool for detection of B. mallei.

scholarly journals COVID-19 – the challenge to treat a disease and not a positive RT-PCR test

Pharmacia ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 155-161
Author(s):  
Maria Georgieva Moneva-Sakelarieva ◽  
Yozlem Ali Kobakova ◽  
Petar Yordanov Atanasov ◽  
Danka Petrova Obreshkova ◽  
Stefka Achkova Ivanova ◽  
...  
Keyword(s):  
False Negative ◽  
Rapid Test ◽  
Rt Pcr ◽  
Negative Results ◽  
False Negative Results ◽  
Chest X Ray ◽  
Pulmonary Changes ◽  
Coagulation Status ◽  
Pcr Test

The new pandemic disease COVID is quick spread worldwide.The primary method used for diagnosing of COVID-19 is detecting viral nucleic acids. The main problem with RT-PCR test is the false negative results. The negative RT-PCR does not exclude a SARS-CoV-2 infection and this method should not be used as the only diagnostic criteria. The RT-PCR result does not change the complex treatment of the disease. The aim of the current study is to compare the four groups clinical cases of the different parameters: RT-PCR test, rapid test, clinical picture, laboratory tests as hematology, inflammatory markers, coagulation status and chemistry and imaging examinations: Chest X-ray at and Chest CT scan. Complex therapeutic approach has been implemented: antibiotic, inflammatory, anticoagulants, oxygen therapy, hepatoprotectors, antimycotics, fibrinolytics, probiotics, essential oils, vitamins. During the follow-up period, a tendency for significant reduction and resorption of the pulmonary changes on the CT scans has been seen.

Factors Associated with False Negative and False Positive RT-PCR Test Results for COVID-19 Detection

2021 ◽  
Author(s):  
Shirin Hakimi
Keyword(s):  
False Positive ◽  
False Negative ◽  
Great Accuracy ◽  
Test Time ◽  
Test Results ◽  
Rt Pcr ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain ◽  
Relevant Factors

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has spread rapidly and developed the current pandemic and the stressful lifestyle in addition with extreme pressure on people was the consequence of its increasing mortality rate. Since COVID-19 is highly infectious, it is crucial to diagnose the disease timely and initiate preventive measures to control the epidemic. Therefore, the need for accurate detection of this virus has been increased dramatically. Real-Time reverse-transcription Polymerase Chain Reaction (RT-PCR) tests are considered a gold standard to detect SARS-CoV-2 RNA. Besides, the recent pandemic has posed the most serious challenge in PCR applications to date. Although RT-PCR has great accuracy, some factors can reduce the efficiency of this test. Time of testing and type of sample are typical elements that may cause false negative results. Furthermore, false positive cases would be the result of contamination and unoptimized primers. In this paper, the relevant factors creating false positive and false negative results have been investigated in depth to increase the awareness of clinicians.

scholarly journals Radiologists versus Deep Convolutional Neural Networks: A Comparative Study for Diagnosing COVID-19

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Abdulkader Helwan ◽  
Mohammad Khaleel Sallam Ma’aitah ◽  
Hani Hamdan ◽  
Dilber Uzun Ozsahin ◽  
Ozum Tuncyurek
Keyword(s):  
Neural Networks ◽  
False Negative ◽  
Rt Pcr ◽  
Deep Convolutional Neural Networks ◽  
Efficient Tool ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain ◽  
Low Sensitivity ◽  
Rule Out

The reverse transcriptase polymerase chain reaction (RT-PCR) is still the routinely used test for the diagnosis of SARS-CoV-2 (COVID-19). However, according to several reports, RT-PCR showed a low sensitivity and multiple tests may be required to rule out false negative results. Recently, chest computed tomography (CT) has been an efficient tool to diagnose COVID-19 as it is directly affecting the lungs. In this paper, we investigate the application of pre-trained models in diagnosing patients who are positive for COVID-19 and differentiating it from normal patients, who tested negative for coronavirus. The study aims to compare the generalization capabilities of deep learning models with two thoracic radiologists in diagnosing COVID-19 chest CT images. A dataset of 3000 images was obtained from the Near East Hospital, Cyprus, and used to train and to test the three employed pre-trained models. In a test set of 250 images used to evaluate the deep neural networks and the radiologists, it was found that deep networks (ResNet-18, ResNet-50, and DenseNet-201) can outperform the radiologists in terms of higher accuracy (97.8%), sensitivity (98.1%), specificity (97.3%), precision (98.4%), and F1-score (198.25%), in classifying COVID-19 images.

scholarly journals COVID-19: Test, Test and Test

2020 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Fatima A Saleh ◽  
Aleen Sleem
Keyword(s):  
Diagnostic Testing ◽  
False Negative ◽  
Detection Methods ◽  
Nucleic Acid Detection ◽  
Rt Pcr ◽  
Negative Results ◽  
Immunological Tests ◽  
False Negative Results ◽  
Different Types ◽  
Polymerase Chain

A new virus was identified in late December 2019 when China reported the first cases of pneumonia in Wuhan, and a global COVID-19 pandemic followed. The world was not late to respond, with a number of sweeping measures ranging from social distancing protocols, stringent hygienic practices, and nation-wide lockdowns, as well as COVID-19 testing campaigns in an attempt to prevent the transmission of the disease and contain the pandemic. Currently, different types of diagnostic testing have been adopted globally, such as nucleic acid detection tests, immunological tests and imaging approaches; however, real-time reverse transcriptase–polymerase chain reaction (RT-PCR) remains the “gold standard” for detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pre-analytical factors, such as specimen selection and collection, are crucial for RT-PCR, and any suboptimal collection may contribute to false-negative results. Herein, we address some of the specimen types that have been used in molecular detection methods for COVID-19. However, the pandemic is still evolving, and information might change as more studies are conducted.

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