scholarly journals A Diagnostic Model to Predict SARS-CoV-2 Positivity in Emergency Department Using Routine Admission Hematological Parameters

Diagnostics ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1566
Author(s):  
Rossana Soloperto ◽  
Giovanna Guiotto ◽  
Giuseppe Tozzi ◽  
Maurizio Fumi ◽  
Angelo Tozzi
Keyword(s):  
Emergency Department ◽  
Hematological Parameters ◽  
False Negative ◽  
Diagnostic Errors ◽  
High Sensitivity ◽  
Nasopharyngeal Swab ◽  
Diagnostic Model ◽  
Rt Pcr ◽  
Early Management ◽  
Cumulative Score

Early detection of SARS-CoV-2 in the emergency department (ED) is a crucial necessity, especially in settings of overcrowding: establishing a pre-diagnostic test probability of infection would help to triage patients and reduce diagnostic errors, and it could be useful in resource-limited countries. Here, we established and validated a clinical predictor of infection based on routine admission hematological parameters. The diagnostic model was developed by comparing 85 consecutive patients with symptomatic COVID-19 confirmed by RT-PCR with 85 symptomatic, SARS-CoV-2-negative controls. Abnormal hematological parameters significantly (p < 0.05) associated with SARS-CoV-2 infection were used to derive a “cumulative score” between 0 and 16. The model was validated in an independent cohort of 170 SARS-CoV-2-positive patients. Several routine hematology parameters were significantly (p < 0.05) associated with SARS-CoV-2 infection. A “cumulative score” score ≥7 discriminated COVID-19-postive patients from controls with a sensitivity of 94% and specificity of 100% (p < 0.001). The high sensitivity of the predictive model was confirmed in the prospective validation set, and the cumulative score (i) predicted SARS-CoV-2 positivity even when the first oro-nasopharyngeal swab RT-PCR result was reported as a false negative in both cohorts and (ii) resulted to be independent from disease severity. The cumulative score based on routine blood parameters can be used to predict an early and accurate diagnosis of SARS-CoV-2 infection in symptomatic patients, thereby facilitating triage and optimizing early management and isolation from the COVID-19 free population, particularly useful in overcrowding situations and in resource-poor settings.

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

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.

scholarly journals Diagnosis of SARS-Cov-2 Infection by RT-PCR Using Specimens Other Than Naso- and Oropharyngeal Swabs: A Systematic Review and Meta-Analysis

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 363
Author(s):  
Vânia M. Moreira ◽  
Paulo Mascarenhas ◽  
Vanessa Machado ◽  
João Botelho ◽  
José João Mendes ◽  
...  
Keyword(s):  
Systematic Review ◽  
Clinical Performance ◽  
Point Of Care ◽  
Meta Analysis ◽  
High Sensitivity ◽  
Nasopharyngeal Swab ◽  
Sample Collection ◽  
Rt Pcr ◽  
Oropharyngeal Swab ◽  
Nucleic Acid Assays

The rapid and accurate testing of SARS-CoV-2 infection is still crucial to mitigate, and eventually halt, the spread of this disease. Currently, nasopharyngeal swab (NPS) and oropharyngeal swab (OPS) are the recommended standard sampling techniques, yet, these have some limitations such as the complexity of collection. Hence, several other types of specimens that are easier to obtain are being tested as alternatives to nasal/throat swabs in nucleic acid assays for SARS-CoV-2 detection. This study aims to critically appraise and compare the clinical performance of RT-PCR tests using oral saliva, deep-throat saliva/posterior oropharyngeal saliva (DTS/POS), sputum, urine, feces, and tears/conjunctival swab (CS) against standard specimens (NPS, OPS, or a combination of both). In this systematic review and meta-analysis, five databases (PubMed, Scopus, Web of Science, ClinicalTrial.gov and NIPH Clinical Trial) were searched up to the 30th of December, 2020. Case-control and cohort studies on the detection of SARS-CoV-2 were included. The methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS 2). We identified 1560 entries, 33 of which (1.1%) met all required criteria and were included for the quantitative data analysis. Saliva presented the higher accuracy, 92.1% (95% CI: 70.0–98.3), with an estimated sensitivity of 83.9% (95% CI: 77.4–88.8) and specificity of 96.4% (95% CI: 89.5–98.8). DTS/POS samples had an overall accuracy of 79.7% (95% CI: 43.3–95.3), with an estimated sensitivity of 90.1% (95% CI: 83.3–96.9) and specificity of 63.1% (95% CI: 36.8–89.3). The remaining index specimens could not be adequately assessed given the lack of studies available. Our meta-analysis shows that saliva samples from the oral region provide a high sensitivity and specificity; therefore, these appear to be the best candidates for alternative specimens to NPS/OPS in SARS-CoV-2 detection, with suitable protocols for swab-free sample collection to be determined and validated in the future. The distinction between oral and extra-oral salivary samples will be crucial, since DTS/POS samples may induce a higher rate of false positives. Urine, feces, tears/CS and sputum seem unreliable for diagnosis. Saliva testing may increase testing capacity, ultimately promoting the implementation of truly deployable COVID-19 tests, which could either work at the point-of-care (e.g. hospitals, clinics) or at outbreak control spots (e.g., schools, airports, and nursing homes).

scholarly journals Inappropriate Nasopharyngeal Sampling for SARS-CoV-2 Detection Is a Relevant Cause of False-Negative Reports

2020 ◽  
Vol 163 (3) ◽  
pp. 459-461 ◽  
Author(s):  
Antonio Piras ◽  
Davide Rizzo ◽  
Sergio Uzzau ◽  
Giacomo De Riu ◽  
Salvatore Rubino ◽  
...  
Keyword(s):  
Nasal Obstruction ◽  
Negative Impact ◽  
Present Report ◽  
False Negative ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Radiologic Findings ◽  
Negative Findings ◽  
Current Outbreak ◽  
Polymerase Chain

Reverse transcriptase polymerase chain reaction (RT-PCR) detection of SARS-CoV-2 mRNA on nasopharyngeal swab is the standard for diagnosing active COVID-19 disease in asymptomatic cases and in symptomatic patients without the typical radiologic findings. For the present COVID-19 outbreak in Italy, we describe 4 symptomatic patients with negative RT-PCR results at the first nasopharyngeal swab, which became positive when collected a few hours later by an otolaryngologist. All the patients showed nasal obstruction. The present report suggests that inadequate nasopharyngeal sampling performed by untrained operators in the presence of nasal obstruction can be a relevant case of false-negative findings at RT-PCR, with a clear negative impact on the efforts to contain the current outbreak.

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 COVID-19 pneumonia: Significance of diagnostic approaches other than PCR testing

2020 ◽  
Vol 4 (7) ◽  
pp. 25-28
Author(s):  
Jovan Javorac ◽  
Dejan Živanović ◽  
Ana Milenković ◽  
Zvonko Dimoski
Keyword(s):  
False Negative ◽  
Fatal Outcome ◽  
High Sensitivity ◽  
Lung Parenchyma ◽  
Diagnostic Methods ◽  
Pcr Analysis ◽  
Nasopharyngeal Swab ◽  
Test Results ◽  
Radiological Findings ◽  
Diagnostic Approaches

The infection by SARS-CoV-2 virus leads to the development of COVID-19 disease, which can manifest asymptomatically, or cause pneumonia caracterised by mild to severe symptoms, with potential fatal outcome. The gold diagnostic standard for COVID-19 disease is the PCR analysis of biological materials sampled by nasopharyngeal swab. However, despite the high sensitivity of this diagnostic method, our clinical experience has shown that in some cases, false-negative PCR test results can be obtained. This paper reports a case of a patient with developed pneumonia that could be related to COVID-19 disease based on the clinical picture, laboratory and radiological findings, but two nasopharyngeal swabs were negative for SARS-CoV-2 after PCR analysis. The patient was treated with the therapy recommended for COVID-19, achieving both clinical and radiological improvement, which indicates that the infection by SARS-CoV-2 virus was probably the UN-derlying factor of of the inflammatory process in the lung parenchyma. Therefore, the aim of this paper is to highlight the importance of other diagnostic methods in diagnosing COVID-19, not only PCR testing.

scholarly journals Evaluation of SARS-CoV-2 Antigen-Based Rapid Diagnostic Kits in Pakistan: Formulation of COVID-19 National Testing Strategy.

2020 ◽  
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 ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Cross Sectional ◽  
Negative Results ◽  
Treatment And Prevention

Abstract Rapid 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 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). 100/33000 (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.

scholarly journals Multicenter evaluation of the Panbio™ COVID-19 Rapid Antigen-Detection Test for the diagnosis of SARS-CoV-2 infection

2020 ◽  
Author(s):  
Paloma Merino-Amador ◽  
Jesús Guinea ◽  
Irene Muñoz-Gallego ◽  
Patricia González-Donapetry ◽  
Juan-Carlos Galán ◽  
...  
Keyword(s):  
Viral Load ◽  
Clinical Symptoms ◽  
False Negative ◽  
Rapid Test ◽  
Antigen Detection ◽  
Nasopharyngeal Swab ◽  
Diagnostic Strategy ◽  
Rt Pcr ◽  
University Hospitals ◽  
Kappa Score

AbstractThe standard RT-PCR assay for COVID-19 is laborious and time-consuming, limiting the availability of testing. Rapid antigen-detection tests are faster and less expensive; however, the reliability of these tests must be validated before they can be used widely. The objective of this study was to determine the reliability of the PanbioTM COVID-19 Ag Rapid Test Device (PanbioRT) (Abbott) for SARS-CoV-2 in nasopharyngeal swab specimens. This was a prospective multicenter study in ten Spanish university hospitals of patients from hospital units with clinical symptoms or epidemiological criteria for COVID-19. Patients whose onset of symptoms or exposure was more than 7 days earlier were excluded. Two nasopharyngeal exudate samples were taken to perform the PanbioRT and a diagnostic RT-PCR test. Among the 958 patients studied, 359 (37.5%) were positive by RT-PCR and 325 (33.9%) were also positive by the PanbioRT. Agreement was 95.7% (kappa score: 0.90). All 34 false-negative PanbioRT results were in symptomatic patients, with 23.5% of them at 6–7 days since the onset of symptoms and 58.8% presenting CT >30 values for RT-PCR, indicating a low viral load. Overall sensitivity and specificity for the PanbioRT were 90.5% and 98.8%, respectively. The PanbioRT provides good clinical performance as a point-of-care test, with even more reliable results for patients with a shorter clinical course of the disease or a higher viral load. While this study has had a direct impact on the national diagnostic strategy for COVID-19 in Spain, the results must be interpreted based on the local epidemiological context.

scholarly journals Time scale performance of rapid antigen testing for SARS-COV-2: evaluation of ten rapid antigen assays

2021 ◽  
Author(s):  
Zakarya Abusrewil ◽  
Inas M Alhudiri ◽  
Hamza Kaal ◽  
Salah Edin El Meshri ◽  
Fawzi O Ebrahim ◽  
...  
Keyword(s):  
Sensitivity And Specificity ◽  
Symptom Onset ◽  
False Negative ◽  
Rapid Test ◽  
High Sensitivity ◽  
Molecular Diagnostic ◽  
Nasopharyngeal Swab ◽  
Viral Loads ◽  
Biotechnology Research ◽  
Antigen Tests

Background: There is a great demand for more rapid tests for SARS-COV-2 detection to reduce waiting time, boost public health strategies for combating disease, decrease costs, and prevent overwhelming laboratory capacities. This study was conducted to assess the performance of 10 antigen-based rapid assays for the detection of SARS-CoV-2 in nasopharyngeal swab specimens. Methods: We analyzed 231 nasopharyngeal samples collected from October 2020-December 2020, from suspected COVID-19 cases and contacts of positive cases at Biotechnology Research Center laboratories, Tripoli, Libya. The performance of 10 COVID-19 Ag rapid test devices (Fluorecare, ESPLINE, RapiGen, Abbott Panbio, Flowflex, Acon, Assut Europe, Orient Gene, CerTest, Bioperfectus, AMP) for the detection of SARS-CoV-2 antigen was compared to RT-qPCR. Results: Among the 108 positive samples detected by RT-qPCR, the COVID-19 antigen (Ag) tests detected 83, giving a sensitivity of 76.85% (95% CI, 67.75- 84.43). 161 patients were symptomatic. The median cycle threshold was 25. The mean duration from symptom onset was 6.6 plus/minus 4.3 days. Sensitivity and specificity during the first 6 days of symptoms and in samples with high viral loads ct<25, was 96.4%. No false positives were detected by any of the Ag tests utilized in this study. False negative samples had a median Ct of 34 and average duration of onset of symptoms of 11.3 days (range=5-20). Conclusions: Rapid antigen test diagnosis has high sensitivity and specificity in early disease when patients present less than 7 days of symptom onset. Patients are encouraged to test as soon as they get COVID-19 related symptoms within 1 week and to seek medical advice within 24 hrs. if they develop disturbed smell/taste. The use of rapid antigen tests is important for controlling COVID-19 pandemic and reducing burden on molecular diagnostic laboratories.

scholarly journals Comparison of Tracheal vs Nasopharyngeal Secretions for SARS-CoV-2 RT-PCR Testing in Patients With Tracheostomy

2020 ◽  
pp. 019459982098070
Author(s):  
Anya Costeloe ◽  
Mohammad-Nadim Samad ◽  
Seilesh Babu ◽  
Christopher Metz
Keyword(s):  
Emergency Department ◽  
Cohort Study ◽  
Average Duration ◽  
Control Group ◽  
Nasopharyngeal Swab ◽  
Rt Pcr ◽  
Viral Shedding ◽  
Academic Hospitals ◽  
Viral Testing ◽  
Experimental Group

This study compares nasopharyngeal and tracheal samples for COVID-19 viral testing in patients with a tracheostomy. This was a prospective cohort study done at 2 academic hospitals between March and June 2020. Patients admitted through the emergency department who had a COVID-19 test and an existing tracheostomy or underwent a tracheostomy during the admission period were included. Patients with a positive initial nasopharyngeal swab were placed in the experimental group (n = 8), while those with a negative swab were the control group (n = 7). Nasopharyngeal and tracheal samples underwent COVID-19 testing using the Abbott RealTime SARS-CoV-2 RNA assay. Fourteen patients underwent tracheostomy, and 1 had an existing tracheostomy. The average duration of viral shedding in nasopharyngeal samples was 20.9 days. One patient (6.7%) tested positive in tracheal secretions after a negative nasopharyngeal swab. In the remaining patients (93.3%), the nasopharyngeal and tracheal specimens correlated.

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