Comparison of COVID-19 Antigen Test and HRCT Chest with RT- PCR Test for Diagnosis of COVID-19

Introduction: We aim to compare Rapid Antigen Test and HRCT chest with Reverse Transcriptase-Polymerase chain reaction (RT-PCR) for diagnosis of COVID-19. Methods: This was a cross-sectional analytical study that included patients tested with RT-PCR and at least one of Rapid Antigen test or HRCT chest, conducted at College of Medical Sciences, Bharatpur, from June 2020 to Feb 2021 after obtaining the ethical clearance. Data analysis was done using statistical packages for social sciences version 16. Results: 315 of 755(41.7%) patients had positive RT-PCR and 18.4% of 733 patients had positive antigen test. Of 600 patients, 106(14.0%) were found to have CO-RADS 1,152(20.1%) had CO-RADS 2, 77(10.2%) had CO-RADS 3, 18(2.4%) had CO-RADS 4 and 247(32.7%) had CO-RADS 5 score on HRCT. Rapid Antigen Test was found to have 43.6% sensitivity, 98.6% specificity, 95.6% Positive predictive value (PPV) and 72.1% negative predictive value (NPV).CO-RADS scoring system was able to distinguish between RT-PCR positive and RT-PCR negative results with an average Area under curve 0.787. CO-RADS 5 had a sensitivity of 71.6%, specificity of 85.1%, PPV of 80.6% and NPV of 77.6% for a positive RT-PCR result. A combination of CO-RADS 1 in HRCT chest and Negative Antigen test can predict PCR negative result with 23.6% sensitivity, 97.3% specificity, 90.5% PPV and 54.0% NPV. Conclusions: Rapid Antigen Test is a better tool for confirmation rather than screening of COVID-19. HRCT chest with higher CO-RADS can be useful to diagnose COVID-19 in suspected patients, even if RT-PCR is negative.

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Role of Covid Antigen in the Diagnosis of Covid Positive in Obstetric Patients

10.53350/pjmhs2115103356 ◽

2021 ◽

Vol 15 (10) ◽

pp. 3356-3358

Author(s):

Ambreen Fatima ◽

Nidda Yaseen ◽

Amna Fareed ◽

Kashif Ali Samin ◽

Shumaela Kanwal ◽

...

Keyword(s):

Nucleic Acid ◽

Early Detection ◽

Negative Predictive Value ◽

Predictive Value ◽

False Negative ◽

Nucleic Acid Amplification ◽

Antigen Test ◽

Rt Pcr ◽

Cross Sectional ◽

Specificity And Sensitivity

Background and Aim: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) rapid emergence postured significant challenges on the health system in recent years. The early detection of cases is thought to be critical in preventing this pandemic by coronavirus disease (COVID-19), especially important in the obstetrical population due to theirs numerous interactions with another parturient when hospitalized for delivery. Therefore, the present study aimed to assess the COVID antigen test performance in COVID-positive obstetrics patients. Materials and Methods: This cross-sectional study was conducted on 1296 Covid-19 asymptomatic women admitted to the Obstetrics and Gynaecology Department of Muhammad Teaching Hospital & Medical College, Peshawar and Fauji Foundation Hospital, Rawalpindi for the duration of six months from February 2021 to July 2021. Antigen-based test rapid diagnostic test (RDT) was used for screening out COVID-19 positive obstetrics patients or women through nasopharyngeal swabs. Women with negative rapid antigen test results were confirmed with RT-polymers chain reaction test of nucleic acid amplification tests (NAAT). Ethical approval and informed consent were taken from the hospital ethical committee and each individual respectively. All the known positive COVID-19 patients during admission were excluded. SPSS version 24 was used for data analysis. Results: The overall prevalence of rapid antigen-positive tested patients was 13.2% (171/1296). The prevalence of positive tested women through rapid antigen test, Nucleic Acid Amplification Test (NAAT), and RT-PCR were 27 (2.1%), 51 (3.9%), and 93 (7.2%) respectively. Of the total 1296 rapid antigen tests, 27 were positive, and the false-negative confirmed positive by NAAT was 144.Thus the sensitivity of the rapid antigen test was 15.8% and the negative predictive value was 93.7%. Of the total 298 Nucleic Acid Amplification Tested had sensitivity and negative predictive value of 89.6% and 99.06% respectively. RT-PCR was carried out on 972 patients, positive diagnosed cases were 36 while 15 were initially negative and were positive with the test was repeated. The sensitivity and negative predictive value was 71.45% and 95.8% respectively. Conclusion: Our study found that Ag-RDT plays a significant role in SARS-CoV-2 early detection in infected individuals, with high specificity and sensitivity to disease infectious stage, whether symptomatic or asymptomatic, and can be used as a decision supported tool. Early detection of COVID-19 status in women admitted for delivery could benefit neonatal protection care. Keywords: Covid-19; Rapid antigen test; RT-PCR test

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

10.1101/2022.01.05.22268788 ◽

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.

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Descriptive Analysis of Chest Computed Tomography Scan in Coronavirus Disease 2019 Pneumonia: Correlation with Reverse Transcription-polymerase Chain Reaction and Clinical Features

Open Access Macedonian Journal of Medical Sciences ◽

10.3889/oamjms.2021.6224 ◽

2021 ◽

Vol 9 (B) ◽

pp. 865-871

Author(s):

Rusli Muljadi ◽

Mira Yuniarti ◽

Ricardo Tan ◽

Teodorus Alfons Pratama ◽

Ignatius Bima Prasetya ◽

...

Keyword(s):

Social Sciences ◽

Ct Scan ◽

Cross Sectional Study ◽

Chest Ct ◽

Rt Pcr ◽

Chain Reaction ◽

Cross Sectional ◽

The Social ◽

Polymerase Chain ◽

Chest Ct Scan

BACKGROUND: Reverse transcriptase-polymerase chain reaction (RT-PCR) is the primary diagnostic tool to confirm coronavirus disease 2019 (COVID-2019) due to its high specificity. However, it has relatively low sensitivity and time consuming. In contrast, chest computed tomography (CT) has high sensitivity and achieves quick results. It may, therefore, play a critical role in screening and diagnosing COVID-19. A cross-sectional study was done in 212 patients with confirmed cases and patients under surveillance for COVID-19 tested for RT-PCR and chest CT scan. Statistical analysis was performed using SPSS Version 23 (Statistical Package for the Social Sciences, IBM Corp., Armonk, NY, USA). AIM: We aim to investigate the diagnostic value of chest CT in correlation to RT-PCR in Indonesia. METHODS: A cross-sectional study was done in 212 patients with confirmed cases and patients under surveillance for COVID-19 tested for RT-PCR and chest CT scan. Statistical analysis was performed using SPSS Version 23 (Statistical Package for the Social Sciences, IBM Corp., Armonk, NY, USA). RESULTS: From a total of 212 patients, 92% of them were diagnosed as confirmed cases of COVID-19. It was found that the sensitivity of CT scan for COVID-19 patients was 72.3% (65.5% and 78.5%) with positive predictive value (PPV) of 93.9% (90.9% and 96.0%) and the sensitivity and PPV improve in symptomatic patients. Typical chest CT scan lesions were 8.0 times which were more likely (3.9–16.4; p <0.001) to be detected in symptomatic patients while patients with severe CT scan findings were 4.4 times more likely (3.0–6.5; p <0.001) to be admitted to the intensive care unit. CONCLUSION: A high PPV suggests that a chest CT scan can detect COVID-19 lesions, but the absence of the lesions would not exclude the disease’s presence.

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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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A meta-analysis of accuracy and sensitivity of chest CT and RT-PCR in COVID-19 diagnosis

Scientific Reports ◽

10.1038/s41598-020-80061-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Fatemeh Khatami ◽

Mohammad Saatchi ◽

Seyed Saeed Tamehri Zadeh ◽

Zahra Sadat Aghamir ◽

Alireza Namazi Shabestari ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Reverse Transcriptase ◽

Ct Scan ◽

Predictive Value ◽

Meta Analysis ◽

Chest Ct ◽

Rt Pcr ◽

Chain Reaction ◽

Polymerase Chain ◽

Chest Ct Scan

AbstractNowadays there is an ongoing acute respiratory outbreak caused by the novel highly contagious coronavirus (COVID-19). The diagnostic protocol is based on quantitative reverse-transcription polymerase chain reaction (RT-PCR) and chests CT scan, with uncertain accuracy. This meta-analysis study determines the diagnostic value of an initial chest CT scan in patients with COVID-19 infection in comparison with RT-PCR. Three main databases; PubMed (MEDLINE), Scopus, and EMBASE were systematically searched for all published literature from January 1st, 2019, to the 21st May 2020 with the keywords "COVID19 virus", "2019 novel coronavirus", "Wuhan coronavirus", "2019-nCoV", "X-Ray Computed Tomography", "Polymerase Chain Reaction", "Reverse Transcriptase PCR", and "PCR Reverse Transcriptase". All relevant case-series, cross-sectional, and cohort studies were selected. Data extraction and analysis were performed using STATA v.14.0SE (College Station, TX, USA) and RevMan 5. Among 1022 articles, 60 studies were eligible for totalizing 5744 patients. The overall sensitivity, specificity, positive predictive value, and negative predictive value of chest CT scan compared to RT-PCR were 87% (95% CI 85–90%), 46% (95% CI 29–63%), 69% (95% CI 56–72%), and 89% (95% CI 82–96%), respectively. It is important to rely on the repeated RT-PCR three times to give 99% accuracy, especially in negative samples. Regarding the overall diagnostic sensitivity of 87% for chest CT, the RT-PCR testing is essential and should be repeated to escape misdiagnosis.

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Reactive Lymphoid Hyperplasia or Tubercular Lymphadenitis: Can Real-Time PCR on Fine-Needle Aspirates Help Physicians in Concluding the Diagnosis?

Acta Cytologica ◽

10.1159/000488871 ◽

2018 ◽

Vol 62 (3) ◽

pp. 204-208 ◽

Cited By ~ 1

Author(s):

Vivek Gupta ◽

Arvind Bhake

Keyword(s):

Lymph Node ◽

Lymph Nodes ◽

Real Time ◽

Predictive Value ◽

Lymphoid Hyperplasia ◽

Reactive Lymphoid Hyperplasia ◽

Rt Pcr ◽

Likelihood Ratios ◽

Diagnostic Challenge ◽

Cross Sectional

Background: Enlarged lymph nodes in adult patients often present a diagnostic challenge. In the absence of granuloma or necrosis, the cytology/tissue findings are misleading and relate the enlarged lymph nodes to reactive lymphoid hyperplasia (RLH), because granuloma formation is an immunological response that usually takes 14–100 days to develop. This study assesses the role of real-time (RT)-PCR in the diagnosis of the Mycobacterium complex (MTBC) in lymph node aspirates compared with culture in cases of RLH. Methods: A cross-sectional study was conducted on 112 patients, aged 15–74 years, with a diagnosis of RLH on cytology. RT-PCR for MTBC detection and culture on Löwenstein-Jensen medium for tubercular bacilli was done on lymph node aspirates. Comparative values with reference to culture were calculated. The χ2 value, positive predictive value (PPV), negative predictive value (NPV), and likelihood ratios (LR) were calculated. Results: Out of 112 RLH cases, 35 (31%) were positive on both RT-PCR and culture. RT-PCR was positive in 43 cases and culture was positive in 44 cases. The χ2 test was found to be highly significant. PPV, NPV, positive LR, and negative LR were 81.4%, 87%, 6.76, and 0.23, respectively. Conclusion: RT-PCR for MTBC proves to be useful in arriving at a conclusive diagnosis in patients with a cytological diagnosis of RLH.

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Self-medication Pattern and Prevalence Among Iranian Medical Sciences Students

Current Drug Safety ◽

10.2174/1574886314666191022095058 ◽

2020 ◽

Vol 15 (1) ◽

pp. 45-52 ◽

Cited By ~ 2

Author(s):

Nastaran Niroomand ◽

Mohsen Bayati ◽

Mozhgan Seif ◽

Somayeh Delavari ◽

Sajad Delavari

Keyword(s):

Medical Science ◽

Cross Sectional Study ◽

Medical Sciences ◽

Negative Effects ◽

Self Medication ◽

Medication Usage ◽

Chi Square ◽

Cross Sectional ◽

Over The Counter ◽

Negative Results

Background: Self-medication could be risky behavior and has negative effects. While Over the Counter (OTC) drugs are available at drugstores, the behavior has become prevalent among the general population. Objective: This study aimed at surveying self-medication behavior among medical sciences students of Shiraz, Iran. Methods: A sample of 396 students from medical, paramedical, and health sciences disciplines were included in this cross-sectional study. They were asked to fill a questionnaire about their demographics and socioeconomic status, medication usage and self-medication in the last six months, information about the correct use of medication, and information about negative results of selfmedication. Data were analyzed using chi-square, t-test and logistic regression model using R statistical software. Results: Almost 72% of participants reported self-medication in the past sixth months. The main reasons included trust in their own diagnosis (59.9%), mildness of the disease (56.6%), and having previous experience about the disease (56%). Cough or cold (84.5%), headache (66.3%), and body pain (60.2%) were the most frequent diseases that led to self-medication. The majority of the participants (77.7%) reported they select their medicine on their own decision. Furthermore, self-medication was highly related to having medicine stock at home (OR=2.692), having less information about negative results of self-medication (OR=0.835), and more non-syllabus study time (OR=1.041). Conclusions: Although, medical science students have information about the treatment of illnesses, they should be more informed about negative results and side-effects of self-medication. They should also share their knowledge with society to decrease self-medication.

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Evaluation of Etiology of Epistaxis and its Management in Dhulikhel Hospital

Kathmandu University Medical Journal ◽

10.3126/kumj.v13i1.13753 ◽

2015 ◽

Vol 13 (1) ◽

pp. 49-55 ◽

Cited By ~ 1

Author(s):

I Shrestha ◽

M Pokharel ◽

BL Shrestha ◽

A Dhakal ◽

RCM Amatya

Keyword(s):

Surgical Treatment ◽

Analytical Study ◽

Cost Effective ◽

Medical Intervention ◽

P Value ◽

Medical Sciences ◽

Cross Sectional ◽

Institutional Review ◽

Specific Objective ◽

Non Surgical Treatment

Background Epistaxis is one of the most common and most difficult emergencies presenting in 7-14% of the general population each year. Although its lifetime incidence is about 60%, only 6% require formal medical intervention but they can be serious and even life threatening.Objective The main objectives are to study different etiology, types, modality of treatment of epistaxis. Specific objective is also to find out if the modality of treatment is associated with age, site, amount of bleeding and etiology.Method It is a prospective, cross sectional, longitudinal, analytical study done in Department of ENT, Dhulikhel hospital, Kathmandu University School of Medical Sciences (KUSMS) from Aug. 2010 to Aug. 2013. Data was collected. This study was cleared through institutional review committee of hospital. Statistical analysis was done using SPSS 16.0.Result 487 patients were studied during the period. There was significant association between age group with type of treatment (p value 0.002); and with admission (p value < 0.001). Significance in the study was also shown in the correlation between site of bleeding and the type of treatment and also with alcohol intake with site of bleeding (p value < 0.001).However there was no significance between hypertension and the type of treatment methods chosen (p value >0.01).Conclusion Management of epistaxis is challenging. Most are managed by non surgical means whereas some by surgical treatment. Non surgical treatment is still useful, safe and cost effective. Type of treatment and need for hospital stay is related to age and site of bleeding.Kathmandu University Medical Journal Vol.13(1) 2015; 49-55

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Accuracy of real-time polymerase chain reaction to detect Schistosoma mansoni – infected individuals from an endemic area with low parasite loads

Parasitology ◽

10.1017/s003118202000089x ◽

2020 ◽

Vol 147 (10) ◽

pp. 1140-1148

Author(s):

Fernanda do Carmo Magalhães ◽

Samira Diniz Resende ◽

Carolina Senra ◽

Carlos Graeff-Teixeira ◽

Martin Johannes Enk ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Schistosoma Mansoni ◽

Real Time ◽

Diagnostic Methods ◽

Control Measures ◽

Rt Pcr ◽

Chain Reaction ◽

Cross Sectional ◽

Intestinal Schistosomiasis ◽

Polymerase Chain

AbstractDue to the efforts to control schistosomiasis transmission in tropical countries, a large proportion of individuals from endemic areas present low parasite loads, which hinders diagnosis of intestinal schistosomiasis by the Kato-Katz (KK) method. Therefore, the development of more sensitive diagnostic methods is essential for efficient control measures. The aim was to evaluate the accuracy of a real-time polymerase chain reaction (RT-PCR) to detect Schistosoma mansoni DNA in fecal samples of individuals with low parasite loads. A cross-sectional population-based study was conducted in a rural community (n = 257) in Brazil. POC-CCA® was performed in urine and feces were used for RT-PCR. In addition, fecal exams were completed by 18 KK slides, saline gradient and Helmintex techniques. The combined results of the three parasitological tests detected schistosome eggs in 118 participants (45.9%) and composed the consolidated reference standard (CRS). By RT-PCR, 117 out of 215 tested samples were positive, showing 91.4% sensitivity, 80.2% specificity and good concordance with the CRS (kappa = 0.71). RT-PCR identified 86.9% of the individuals eliminating less than 12 eggs/g of feces, demonstrating much better performance than POC-CCA® (50.8%). Our results showed that RT-PCR is a valuable alternative for the diagnosis of intestinal schistosomiasis in individuals with very low parasite loads.

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Prognostic Value of Circulating Melanoma Cells Detected by Reverse Transcriptase–Polymerase Chain Reaction

Journal of Clinical Oncology ◽

10.1200/jco.2003.01.128 ◽

2003 ◽

Vol 21 (5) ◽

pp. 767-773 ◽

Cited By ~ 65

Author(s):

Giuseppe Palmieri ◽

Paolo A. Ascierto ◽

Francesco Perrone ◽

Sabrina M.R. Satriano ◽

Alessandro Ottaiano ◽

...

Keyword(s):

Polymerase Chain Reaction ◽

Subgroup Analysis ◽

Peripheral Blood ◽

Predictive Value ◽

Prognostic Value ◽

Rt Pcr ◽

Chain Reaction ◽

Blood Samples ◽

Stage Of Disease ◽

Polymerase Chain

Purpose: Factors that are predictive of prognosis in patients who are diagnosed with malignant melanoma (MM) are widely awaited. Detection of circulating melanoma cells (CMCs) by reverse transcriptase-polymerase chain reaction (RT-PCR) has recently been postulated as a possible negative prognostic factor. Two main questions were addressed: first, whether the presence of CMCs, defined as the patient being positive for any of the three markers, had a prognostic role; and second, what the predictive value of each individual marker was. Patients and Methods: A consecutive series of 200 melanoma patients observed between January 1997 and December 1997, with stage of disease ranging from I to IV, was analyzed by semiquantitative RT-PCR. Tyrosinase, p97, and MelanA/MART1 were used as markers to CMCs on baseline peripheral blood samples. Progression-free survival (PFS) was used as a unique end point and was described by the product limit method. Multivariable analysis was applied to verify whether the auspicated prognostic value of these markers was independent of the stage of disease, and a subgroup analysis was performed that excluded patients with stage IV disease. Results: Overall, 32% (64 of 200) of patients progressed, and a median PFS of 52 months in the whole series was observed. The presence of CMCs and the markers individually or combined was predictive of prognosis in the univariate analysis but did not provide additional prognostic information to the stage of disease in multivariable models. In the subgroup analysis of stage (ie, I–III subgroup), similar results were observed. Conclusion: Detection of CMCs in peripheral blood samples at the time of MM diagnosis by semiquantitative RT-PCR does not add any significant predictive value to the stage of disease. Thus, this approach should not be used in clinical practice, and further studies are required to determine its usefulness.

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