Scoring System for the Diagnosis of COVID-19

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.

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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

Canadian Respiratory Journal ◽

10.1155/2020/4648307 ◽

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.

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

European Journal of Case Reports in Internal Medicine ◽

10.12890/2020_001680 ◽

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).

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

Pharmacia ◽

10.3897/pharmacia.68.e61906 ◽

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.

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

Iranian Journal of Allergy Asthma and Immunology ◽

10.18502/ijaai.v20i4.6949 ◽

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.

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Performance Characteristics of BinaxNOW COVID-19 Antigen Card for Screening Asymptomatic Individuals in a University Setting

Journal of Clinical Microbiology ◽

10.1128/jcm.03282-20 ◽

2021 ◽

Author(s):

Nkemakonam C Okoye ◽

Adam P Barker ◽

Kenneth Curtis ◽

Richard R Orlandi ◽

Emily A Snavely ◽

...

Keyword(s):

False Negative ◽

Analytical Sensitivity ◽

Rt Pcr ◽

Pcr Assay ◽

Viral Loads ◽

University Of Utah ◽

Negative Results ◽

False Negative Results ◽

Asymptomatic Individuals ◽

Positive Agreement

We compared the performance of the Abbott BinaxNOW COVID-19 Antigen Card to a standard RT-PCR assay (ThermoFisher TaqPath COVID-19 Combo Kit) for the detection of SARS-CoV-2 in 2,645 asymptomatic students presenting for screening at the University of Utah. SARS-CoV-2 RNA was detected in 1.7% of the study participants by RT-PCR. BinaxNOW identified 24 infections but missed 21 infections that were detected by RT-PCR. The analytical sensitivity (positive agreement) and analytical specificity (negative agreement) for the BinaxNOW was 53.3% and 100%, respectively when compared against the RT-PCR assay. The median cycle threshold (Ct) value in the specimens that had concordant positive BinaxNOW antigen result was significantly lower compared to those that were discordant (Ct 17.6 vs. 29.6; p < 0.001). In individuals with presumably high viral loads (Ct < 23.0), a 95.8% positive agreement was observed between the RT-PCR assay and BinaxNOW. Due to the possibility of false negative results, caution must be taken when utilizing rapid antigen testing for screening asymptomatic individuals.

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Evaluation of SARS-CoV-2 antigen-based rapid diagnostic kits in Pakistan: formulation of COVID-19 national testing strategy

Virology Journal ◽

10.1186/s12985-021-01505-3 ◽

2021 ◽

Vol 18 (1) ◽

Author(s):

Umar Saeed ◽

Sara Rizwan Uppal ◽

Zahra Zahid Piracha ◽

Azhar Rasheed ◽

Zubair Aftab ◽

...

Keyword(s):

Gold Standard ◽

Injection Drug Users ◽

Drug Users ◽

Diagnostic Testing ◽

False Negative ◽

Cross Sectional Study ◽

Nasopharyngeal Swab ◽

Rt Pcr ◽

Cross Sectional ◽

Negative Results

AbstractRapid diagnosis of SARS-CoV-2 during pandemic enables timely treatment and prevention of COVID-19. Evaluating the accuracy and reliability of rapid diagnostic testing kits is crucial for surveillance and diagnosis of SARS-CoV-2 infections in general population, injection drug users, multi-transfused populations, healthcare workers, prisoners, barbers and other high risk populations. The aim of this study was to evaluate performance and effectiveness of nasopharyngeal swab (NSP) and saliva based rapid antigen detection testing kits in comparison with USFDA approved triple target gold standard real-time polymerase chain reaction. A cross-sectional study was conducted on 33,000 COVID-19 suspected patients. From RT-PCR positive patients, nasopharyngeal swab (NSP) and saliva samples were obtained for evaluation of rapid COVID-19 testing kits (RDT). 100/33,000 (0.3%) of specimens were RT-PCR positive for SARS-CoV-2. Among RT-PCR positive, 62% were males, 34% were females, and 4% were children. The NSP-RDT (Lepu Medical China) analysis revealed 53% reactivity among males, 58% reactivity among females, and 25% reactivity among children. However saliva based RDT (Lepu Medical China) analysis showed 21% reactivity among males and 23% among females, and no reactivity in children. False negative results were significantly more pronounced in saliva based RDT as compared to NSP-RDT. The sensitivity of these NSP-RDT and saliva based RDT were 52% and 21% respectively. The RDTs evaluated in this study showed limited sensitivities in comparison to gold standard RT-PCR, indicating that there is a dire need in Pakistan for development of suitable testing to improve accurate COVID-19 diagnosis in line with national demands.

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Superiority of MALDI-TOF Mass Spectrometry over Real-Time PCR for SARS-CoV-2 RNA Detection

Viruses ◽

10.3390/v13050730 ◽

2021 ◽

Vol 13 (5) ◽

pp. 730

Author(s):

Magda Rybicka ◽

Ewa Miłosz ◽

Krzysztof Piotr Bielawski

Keyword(s):

Mass Spectrometry ◽

Gold Standard ◽

Viral Genome ◽

False Negative ◽

Rt Pcr ◽

Rna Detection ◽

Maldi Tof ◽

Negative Results ◽

False Negative Results ◽

Pcr Test

At present, the RT-PCR test remains the gold standard for early diagnosis of SARS-CoV-2. Nevertheless, there is growing evidence demonstrating that this technique may generate false-negative results. Here, we aimed to compare the new mass spectrometry-based assay MassARRAY® SARS-CoV-2 Panel with the RT-PCR diagnostic test approved for clinical use. The study group consisted of 168 suspected patients with symptoms of a respiratory infection. After simultaneous analysis by RT-PCR and mass spectrometry methods, we obtained discordant results for 17 samples (10.12%). Within fifteen samples officially reported as presumptive positive, 13 were positive according to the MS-based assay. Moreover, four samples reported by the officially approved RT-PCR as negative were positive in at least one MS assay. We have successfully demonstrated superior sensitivity of the MS-based assay in SARS-CoV-2 detection, showing that MALDI-TOF MS seems to be ideal for the detection as well as discrimination of mutations within the viral genome.

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Distribution of SARS-CoV-2 PCR Cycle Threshold Values Provide Practical Insight Into Overall and Target-Specific Sensitivity Among Symptomatic Patients

American Journal of Clinical Pathology ◽

10.1093/ajcp/aqaa133 ◽

2020 ◽

Vol 154 (4) ◽

pp. 479-485 ◽

Cited By ~ 4

Author(s):

Blake W Buchan ◽

Jessica S Hoff ◽

Cameron G Gmehlin ◽

Adriana Perez ◽

Matthew L Faron ◽

...

Keyword(s):

Viral Load ◽

Limit Of Detection ◽

False Negative ◽

Age Group ◽

Rt Pcr ◽

Patient Age ◽

Cycle Threshold ◽

Negative Results ◽

Patient Âgé ◽

False Negative Results

Abstract Objectives We examined the distribution of reverse transcription polymerase chain reaction (RT-PCR) cycle threshold (CT) values obtained from symptomatic patients being evaluated for coronavirus disease 2019 (COVID-19) to determine the proportion of specimens containing a viral load near the assay limit of detection (LoD) to gain practical insight to the risk of false-negative results. We also examined the relationship between CT value and patient age to determine any age-dependent difference in viral load or test sensitivity. Methods We collected CT values obtained from the cobas severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) assay corresponding to 1,213 combined nasopharyngeal-oropharyngeal specimens obtained from symptomatic individuals that were reported as positive or presumptive positive for SARS-CoV-2. CT values were stratified by SARS-CoV target and patient age group. Results In total, 93.3% to 98.4% of specimens demonstrated CT values greater than 3× the assay LoD, at which point false-negative results would not be expected. The mean of CT values between age groups was statistically equivalent with the exception of patients in age group 80 to 89 years, which demonstrated slightly lower CTs. Conclusions Based on the distribution of observed CT values, including the small proportion of specimens with values near the assay LoD, there is a low risk of false-negative RT-PCR results in combined nasopharyngeal-oropharyngeal specimens obtained from symptomatic individuals.

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