scholarly journals Virology, Molecular Pathogenesis and Diagnosis of SARS-CoV-2: A Systematic Review

2021 ◽  
Vol 23 (08) ◽  
pp. 352-365
Author(s):  
Vyas Sonal ◽  
◽  
Kaur Jasmine ◽  
Pahari Pratyay Kumar ◽  
Nain Parminder ◽  
...  
Keyword(s):  
Systematic Review ◽  
Nucleic Acid ◽  
Detection Method ◽  
Nucleic Acid Amplification Test ◽  
Molecular Pathogenesis ◽  
Diagnostic Methods ◽  
Nucleic Acid Amplification ◽  
Swine Flu ◽  
Molecular Virology ◽  
Different Types

After past episodes of Zika, Nipah and Ebola viruses and also previous emergencies due to other viruses like swine flu and bird flu viruses, now in 21st century global disaster caused by nCoV virus. As the virus is still investigated for proper identification, there are very less option in choosing the proper detection method. So we have reviewed various article for giving an idea about pathogenesis and diagnostic methods. We had screened Google Scholar database with the keywords nCoV pathogenesis, molecular immune pathogenesis of COVID-19, virology of SARS-CoV-2, diagnosis of SARS-CoV-2 and advancement of nCoV diagnosis. In the final review we have included a total of 84 articles. As a result we have reviewed the molecular virology along with molecular pathogenesis of COVID-19 in human body. We have found various ongoing researches on detection of nCoV related to nucleic acid amplification test, different types of RT-qPCR, serological assay and different HRCT methods.

scholarly journals A Retrospective Cross-Sectional Study of the Utility of Cartridge-Based Nucleic Acid Amplification Test in Diagnosis of Pulmonary and Extrapulmonary Tuberculosis in People Living with HIV in Second Highest HIV Prevalent State in India

2021 ◽  
Author(s):  
Tade Bagbi ◽  
Ningthoukhongjam Reema ◽  
S. Bhagyabati Devi ◽  
Thangjam Gautam Singh ◽  
Mohammad Jaleel ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Cross Sectional Study ◽  
Nucleic Acid Amplification Test ◽  
Nucleic Acid Amplification ◽  
Rifampicin Resistance ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Sectional Study ◽  
Cross Sectional ◽  
Smear Negative

Abstract Introduction Tuberculosis (TB) in people living with human immunodeficiency virus (PLHIV) is difficult to diagnose due to fewer organisms in sputum and extrapulmonary samples. Sputum culture takes 4 to 8 weeks for growth of the mycobacteria. Delayed treatment for TB in PLHIV leads to increased mortality. This study evaluated cartridge-based nucleic acid amplification test (CBNAAT) as a diagnostic tool for diagnosis of pulmonary TB (PTB) and extrapulmonary TB (EPTB) in PLHIV in the second most HIV prevalent state in India and for comparing its efficacy between Ziehl–Neelsen (ZN) staining sputum smear–positive and sputum smear–negative TB. Methods This cross-sectional study was conducted in RIMS, Imphal, with 167 PLHIV patients, age 15 years or older, having signs and symptoms of TB. Appropriate samples for sputum microscopy and CBNAAT were sent. Conclusion The overall sensitivity of sputum smear for acid-fast bacillus (AFB) was found to be 30.71% and that of CBNAAT was 38.57%. Sensitivity of CBNAAT for sputum smear–positive and sputum smear–negative TB was 100 and 11.3%, respectively. Sensitivity of ZN smear for AFB of EPTB sample was 48.1% and that of CBNAAT was 59.25%. In both PTB and EPTB, CBNAAT showed an increase in diagnosis of microbiologically confirmed PTB cases by 7.8 and 11.1%, respectively, over and above the cases diagnosed by ZN smear microscopy. Rifampicin resistance was detected in five patients. We conclude that CBNAAT is a rapid test with better sensitivity in diagnosis of PTB and EPTB in PLHIV, compared with ZN smear microscopy. It detects rifampicin resistance for multidrug-resistant TB and helps in early treatment intervention.

scholarly journals Nucleic Acid Amplification Test Quantitation as Predictor of Toxin Presence in Clostridium difficile Infection

2017 ◽  
Vol 56 (3) ◽  
Author(s):  
M. J. T. Crobach ◽  
N. Duszenko ◽  
E. M. Terveer ◽  
C. M. Verduin ◽  
E. J. Kuijper
Keyword(s):  
Nucleic Acid ◽  
Clostridium Difficile ◽  
Characteristic Curve ◽  
Nucleic Acid Amplification Test ◽  
Nucleic Acid Amplification ◽  
Toxin A ◽  
Toxin B ◽  
Content Type ◽  
Quantitative Results ◽  
Testing Algorithm

ABSTRACT Multistep algorithmic testing in which a sensitive nucleic acid amplification test (NAAT) is followed by a specific toxin A and toxin B enzyme immunoassay (EIA) is among the most accurate methods for Clostridium difficile infection (CDI) diagnosis. The obvious shortcoming of this approach is that multiple tests must be performed to establish a CDI diagnosis, which may delay treatment. Therefore, we sought to determine whether a preliminary diagnosis could be made on the basis of the quantitative results of the first test in algorithmic testing, which provide a measure of organism burden. To do so, we retrospectively analyzed two large collections of samples ( n = 2,669 and n = 1,718) that were submitted to the laboratories of two Dutch hospitals for CDI testing. Both hospitals apply a two-step testing algorithm in which a NAAT is followed by a toxin A/B EIA. Of all samples, 208 and 113 samples, respectively, tested positive by NAAT. Among these NAAT-positive samples, significantly lower mean quantification cycle ( C q ) values were found for patients whose stool eventually tested positive for toxin, compared with patients who tested negative for toxin (mean C q values of 24.4 versus 30.4 and 26.8 versus 32.2; P < 0.001 for both cohorts). Receiver operating characteristic curve analysis was performed to investigate the ability of C q values to predict toxin status and yielded areas under the curve of 0.826 and 0.854. Using the optimal C q cutoff values, prediction of the eventual toxin A/B EIA results was accurate for 78.9% and 80.5% of samples, respectively. In conclusion, C q values can serve as predictors of toxin status but, due to the suboptimal correlation between the two tests, additional toxin testing is still needed.

scholarly journals Prospective study to find out the role of gastric aspirate examination by Ziehl-Neelsen staining (ZN staining) and cartridge based nucleic acid amplification test (CB-NAAT) as a diagnostic method in childhood tuberculosis

2018 ◽  
Vol 5 (4) ◽  
pp. 1609
Author(s):  
Akansha Arora ◽  
Anil Jain ◽  
B. S. Karnawat ◽  
Rakesh Kumawat
Keyword(s):  
Nucleic Acid ◽  
Predictive Value ◽  
Nucleic Acid Amplification Test ◽  
Nucleic Acid Amplification ◽  
Mantoux Test ◽  
P Value ◽  
Specific Method ◽  
Gastric Aspirate ◽  
Tuberculosis In Children

Background: Tuberculosis in children has been relatively neglected mainly because clinical diagnosis has low specificity, radiological interpretation is subject to inter-observer variability and the tuberculin skin test is a marker of exposure, not disease. The recent introduction of Cartridge based nucleic acid amplification test has significantly transformed the diagnostics of tuberculosis in adults but its application for Paediatric Tuberculosis is under evaluation. Therefore, authors conducted a study on role of gastric aspirate examination by ZN stain and Cartridge based nucleic acid amplification test in the diagnosis of childhood Tuberculosis.Methods: Authors did a prospective hospital-based study from Nov 2016 to Nov 2017 consisting of 100 randomly selected patients suspected of tuberculosis who had their gastric aspirate tested for CBNAAT and ZN stain for acid fast bacilli (AFB) along with Mantoux test and other routine investigations. Chi square test was used.Results: Culture positive tuberculosis was found in 21 out of 100 children. The sensitivity, specificity, positive predictive value and negative predictive value for CBNAAT were 76.1%, 98.7%, 94.1% and 93.9% and for ZN stain were 47.6%, 98.7%, 90.9% and 87.6% respectively. Positive history of contact (p value 0.0217), reactive Mantoux test (p value < 0.001) and low socioeconomic status were independently associated with a positive CBNAAT result.Conclusions: Analysis of gastric aspirate samples with CBNAAT is a sensitive and specific method for rapid diagnosis of pulmonary tuberculosis in children who cannot produce sputum. Compared with microscopy, CBNAAT offers better sensitivity and its scale up will improve access to tuberculosis diagnostics in children.

scholarly journals EVALUATION OF CARTRIDGE-BASED NUCLEIC ACID AMPLIFICATION TEST FOR DIAGNOSIS OF TUBERCULOSIS IN CHILDREN IN VARIOUS BODY FLUIDS

2019 ◽  
Vol 6 (7) ◽  
pp. 349-352
Author(s):  
Dipti Agarwal ◽  
Rakesh Bhatia ◽  
Rajeshwar Dayal ◽  
Rhythm Khera ◽  
Shamrendra Narayan ◽  
...  
Keyword(s):  
Nucleic Acid ◽  
Body Fluids ◽  
Nucleic Acid Amplification Test ◽  
Nucleic Acid Amplification ◽  
Tuberculosis In Children

scholarly journals Association of Cartridge Based Nucleic Acid Amplification Test (CBNAAT) Grading on the Basis of Cycle Threshold Value with Conventional Microbiological Diagnosis in Pediatric Tuberculosis

2021 ◽  
Vol 7 (2) ◽  
pp. 72-77
Author(s):  
Bineeta Kashyap ◽  
Neha Gupta ◽  
Pooja Dewan ◽  
NP Singh ◽  
Ashwani Khanna
Keyword(s):  
Nucleic Acid ◽  
Positive Association ◽  
Threshold Value ◽  
Nucleic Acid Amplification Test ◽  
Nucleic Acid Amplification ◽  
Microbiological Diagnosis ◽  
Significant Positive Association ◽  
Cycle Threshold ◽  
Culture Positivity ◽  
Pediatric Tuberculosis

Background: Microbiological confirmation of tuberculosis disease in children remains difficult due to paucibacillary disease and inability to obtain optimal samples. Recently introduced Cartridge based nucleic acid amplification test (CBNAAT) has improved microbiological diagnosis in pediatric tuberculosis. Objectives: We aimed to study association of CBNAAT grading based on cycle threshold value with conventional microbiological diagnosis. Methodology: This prospective study was conducted over a period from November 2016 to October 2017 in the Departments of Microbiology and Pediatrics, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi. CBNAAT positive pediatric TB cases ≤12 years were recruited and subjected to Ziehl-Neelsen staining for acid fast bacilli (AFB) & culture on Lowenstein Jensen medium. CBNAAT positivity was graded based on cycle threshold value: very low, low, medium and high. Results: Smear and culture positivity was highest (100%) among specimens with high positive CBNAAT result based on CT value. Time to culture positivity was inversely related to CBNAAT grading (p=0.000). Conclusion: CBNAAT grading has significant positive association with smear and culture positivity. Bangladesh Journal of Infectious Diseases 2020;7(2):72-77

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