scholarly journals Comparison of Auramine Phenol and ZN Staining in Diagnosis of Pulmonary Tuberculosis with GeneXpert MTB/RIF as Gold Standard

2020 ◽  
Vol 9 (3) ◽  
pp. 190-194
Author(s):  
Naureen Saeed ◽  
Fatima-tuz-zuhra ◽  
Nadeem Ikram ◽  
Farhana Shaukat ◽  
Fareeha Sardar
Keyword(s):  
Pulmonary Tuberculosis ◽  
Positive Predictive Value ◽  
Predictive Value ◽  
Gold Standard ◽  
Sputum Sample ◽  
False Negative ◽  
Smear Microscopy ◽  
Predictive Values ◽  
Pulmonary Tb ◽  
Sensitivity Specificity

Background: Pakistan faces an immense burden of pulmonary tuberculosis (TB) due to large number of cases and limited resources. Despite the recent advancement in the diagnostic techniques for pulmonary TB, smear microscopy is still a useful technique for the diagnosis of this disease. This study was conducted in order to compare the diagnostic value of Auramine stain with the conventional Ziehl-Neelsen (ZN) stain on the sputum smear for the diagnosis of pulmonary TB, keeping GeneXpert MTB/RIF as the gold standard. Method: This cross-sectional study was conducted on 356 suspected patients of pulmonary TB referred to the Pathology laboratory from TB ward and OPD of District Head Quarter (DHQ) teaching hospital Rawalpindi, Pakistan. Sputum specimen were collected and two smears were prepared from each sputum sample on which Auramine phenol and Ziehl-Neelsen staining were carried out as per WHO recommendations. All these samples were further tested using Gene Xpert MTB/RIF technique. The sensitivity, specificity, Positive predictive value (PPV) and Negative predictive values (NPV) of ZN and Auramine stain were calculated and compared with GeneXpert MTB/RIF technique. Results: Out of the total 356 samples, 64(18%) were positive and 291(82%) were negative by GeneXpert which was taken as the gold standard. On comparison with GeneXpert, percentage of true positive was greater in case of Auramine than ZN stained samples (16.29% versus 12.92%), while the percentage of false positive was same for both staining techniques (0.28%). There were lesser false negative cases observed in samples stained by Auramine as compared to the ones stained by ZN (1.68% versus 5.05%). The sensitivity, specificity, positive predictive value and negative predictive values were 97.87%, 94.17%, 71.88 and 99.66%, respectively for the ZN staining and 98.31%, 97.98%, 90.63% and 99.66% respectively, for the Auramine phenol staining. Conclusion: Smear microscopy using Auramine phenol stain is a useful technique for the diagnosis of pulmonary TB. The Auramine phenol staining with fluorescent microscopy is found to be superior to ZN staining because of higher sensitivity and specificity. Keywords: Auramine phenol, Fluorescence microscopy, GeneXpert, Mycobacterium tuberculosis, Ziehl-Neelsen

scholarly journals Evaluation of Gene Xpert Mtb/Rif Assay for the Detection of Mycobacterium Tuberculosis in Sputum of Patients Suspected of Pulmonary Tuberculosis Visiting National Tuberculosis Centre, Thimi, Bhaktapur, Nepal

2017 ◽  
Vol 13 (1) ◽  
pp. 16-22
Author(s):  
Ashok Thapa ◽  
P Gurung ◽  
G R Ghimire
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Pulmonary Tuberculosis ◽  
Predictive Value ◽  
Sputum Sample ◽  
Culture Method ◽  
Smear Microscopy ◽  
National Tuberculosis ◽  
Standard Culture ◽  
Sensitivity Specificity ◽  
And Control

Introduction: Tuberculosis (TB) is one of the most deadly and common major infectious diseases in developing countries. Rapid and accurate diagnosis of tuberculosis is indispensable to adequately manage the disease and control its transmission. The objective of this study was to evaluate Gene Xpert MTB/RIF Assay for detection of M. tuberculosis in sputum of patients suspected of pulmonary tuberculosis and its comparison with traditional conventional methods.Methodology: A total of 138 patients sputum samples were collected and processed. Gene Xpert MTB/ RIF Assay, culture method and smear microscopy were performed under standard guideline inside biosafety cabinet class II. Data were reported, structured and analyzed using SPSS version 16.00. Study was carried out from June to November 2014.Results: Assay detected M. tuberculosis in 37 (26.81%) samples out of total 138. Of these 37, 10 and 3 were resistance and indeterminate to rifampicin respectively. Culture, Ziehl-Neelsen staining and Auramine staining were positive in 43 (31.16%), 18 (13.04%) and 24 (17.39%) samples respectively. Sensitivity, specificity, Positive predictive value and Negative predictive value of Assay were 76.74%, 95.79%, 89.19% and 90.09% respectively with reference to gold standard culture method.Conclusions: Assay was found rapid in direct detec tion of Mycobacterium tuberculosis in sputum sample and was also found more sensitive than both Ziehl-Neelsen staining and Auramine staining and especially showed good promise in diagnosis of smear negative specimens.SAARC J TUBER LUNG DIS HIV/AIDS, 2016; XIII(1), page: 16-22

scholarly journals Performance of LED Fluorescence Microscopy for the Diagnosis of Pulmonary Tuberculosis in HIV Positive Individuals in Addis Ababa, Ethiopia

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Konjit Getachew ◽  
Tamrat Abebe ◽  
Abebaw Kebede ◽  
Adane Mihret ◽  
Getachew Melkamu
Keyword(s):  
Pulmonary Tuberculosis ◽  
Predictive Value ◽  
Addis Ababa ◽  
Sputum Sample ◽  
Cross Sectional Study ◽  
Hiv Positive ◽  
Smear Microscopy ◽  
Lower Sensitivity ◽  
Cross Sectional ◽  
Sensitivity Specificity

Background. Despite its lower sensitivity, smear microscopy remains the main diagnostic method for pulmonary tuberculosis (PTB) in resource-limited countries as TB culturing methods like LJ (Lowenstein-Jensen) are expensive to use as a routine base. This study aimed to evaluate the performance of LED-FM for the diagnosis of PTB in HIV positive individuals.Methods. Cross-sectional study was conducted in Zewditu Memorial Hospital and Teklehaimanot Health Center HIV/ART clinics in Addis Ababa, Ethiopia. Each sample was stained with ZN and Auramine O staining and examined with bright-field microscope and LED-FM microscope, respectively. LJ culture was used as a reference.Results. Out of 178 study participants, twenty-four (13.5%) patients were confirmed as positive for MTB with LJ culture. The yield of ZN microscopy and LED-FM in direct and concentrated sample was 3.9%, 8.4%, 6.2%, and 8.4%, respectively. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of direct ZN microscopy were 29.2%, 100%, 100%, and 90.1%, respectively, and of LED-FM microscopy in direct sputum sample were 62.5%, 100%, 100%, and 94.5%, respectively.Conclusion. LED-FM has better sensitivity for the diagnosis of PTB in HIV positive individuals as compared to conventional ZN microscopy. LED-FM can be used as an alternative to conventional ZN microscopy.

scholarly journals Diagnostic Performance of Xpert MTB/RIF Assay Versus Ziehl-Neelsen Method for the Diagnosis of Pulmonary Tuberculosis in Addis Ababa, Ethiopia

2018 ◽  
Vol 12 (1) ◽  
pp. 390-396
Author(s):  
Boja D. Taddese ◽  
Daniel M. Desalegn ◽  
Abay S. Misganaw ◽  
Kumera T. Kitila ◽  
Tinsae Kidanemariam Hailu ◽  
...  
Keyword(s):  
Pulmonary Tuberculosis ◽  
Predictive Value ◽  
Gold Standard ◽  
Addis Ababa ◽  
Public Health Problem ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Sputum Smear Microscopy ◽  
Cross Sectional ◽  
Sensitivity Specificity

Background: Worldwide Tuberculosis (TB) is the ninth leading cause of death from a single infectious agent, positioning on top of Human Immuno Deficiency Virus (HIV) and it is still an eminently serious public health problem. In developing countries, Ziehl-Neelsen (ZN)-stained sputum smear microscopy is the most widely used diagnostic method in diagnosing Pulmonary Tuberculosis (PTB). This study was aimed to compare the diagnostic performances of ZN-method with Xpert MTB/RIF assay for the diagnosis of PTB in Addis Ababa, Ethiopia. Methods: Facility-based cross-sectional study design was conducted from September 2016 to June 2017 on a total of 244 sputum samples collected from presumptive TB patients. The L-J sputum culture was used as a gold standard to compare the diagnostic performances of Xpert MTB/RIF assay and ZN-methods. Kappa values were analyzed by using statistical package for Social Science (SPSS) version 20 software at 95% Confidence Interval (CI). The Sensitivity, Specificity, Positive Predictive Value (PPV) and Negative Predictive Value (NPV) of ZN-stained sputum smear microscopy and Xpert MTB/RIF assay were calculated against the gold standard. Results: The Sensitivity, Specificity, PPV and NPV of ZN-stained sputum smear microscopy were 68.38%, 95.28%, 93.02% and 76.58% respectively, while for Xpert MTB/ RIF assay were 88.89%, 81.89%, 81.89% and 88.89% respectively. The results of the two diagnostic approaches were concordant with the gold standard with a kappa value of ZN 0.650 and 0.743 for Xpert MTB/RIF assay. Conclusion: This study concludes that the sensitivity of Xpert MTB/RIF assay was better than ZN-stained direct sputum smear microscopy for the diagnosis of pulmonary tuberculosis.

scholarly journals Diagnostic value of self-report compared with Beck Depression Inventory (BDI-II) in screening of depression

2020 ◽  
Author(s):  
Mehran zarghami ◽  
Fatemeh Taghizadeh ◽  
Mahmood mousazadeh
Keyword(s):  
Positive Predictive Value ◽  
Beck Depression Inventory ◽  
Predictive Value ◽  
Total Population ◽  
False Negative ◽  
Diagnostic Value ◽  
Self Report ◽  
Case Group ◽  
Predictive Values ◽  
Sensitivity Specificity

AbstractBackgroundDepression is a common cause of mortality and morbidity worldwide. To detect depression, we compared Beck Depression Inventory scoring as a valid tool with participants self-reporting depression.MethodologyThis cross-sectional study aimed to explore the diagnostic values of self-reporting in patients’ with depression comparing to Beck Depression Inventory scoring in Mazandaran Persian cohort study, with a total of 1300 samples. The sample size was determined to include 155 participants through the census method. In order to increase the test power, 310 healthy participants were included in the study through random selection. In order to evaluate the diagnostic value of self-reporting, BDI-II was completed by blind interviewing to the case group as well as to another group who reported that they were not depressed, as control.ResultsSensitivity, specificity, accuracy, false positive, false negative, positive and negative predictive values of self-reporting was calculated 58.4%, 79.1%,73.4%, 20.8%, 41.6%, 51.8%, and 83.2% for the total population respectively, as well as, sensitivity, specificity, accuracy, positive and negative predictive values of self-report in males were 83.3%, 77.2%, 77.1%, 43.8% and 95.6% and 53.7%, 78.1%, 71.2%, 49.2%, and 81.1% for females, respectively.ConclusionThe positive predictive value and sensitivity of self-reporting are insufficient in total population and females, and therefore self-reporting cannot detect depressed patients, but regarding to its average positive predictive value, perhaps, it can be used to identify non-depressant individuals.

scholarly journals Application Value of SAT-TB Combined with Acid-Fast Staining in the Diagnosis and Treatment of Pulmonary Tuberculosis

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Chaochao Qiu ◽  
Ning Pan ◽  
Yueying Zhou ◽  
Hongye Ning ◽  
Xinchun Ye ◽  
...  
Keyword(s):  
Pulmonary Tuberculosis ◽  
Positive Predictive Value ◽  
Predictive Value ◽  
Gold Standard ◽  
Diagnosis And Treatment ◽  
Significant Difference ◽  
Kappa Value ◽  
High Consistency ◽  
Sensitivity Specificity ◽  
Acid Fast Staining

Objectives. This study is aimed at evaluating the clinical application value of RNA simultaneous amplification and testing method for Mycobacterium tuberculosis (SAT-TB) combined with acid-fast staining in the diagnosis and treatment of pulmonary tuberculosis (PTB). Methods. This paper included 168 suspected and confirmed PTB sufferers admitted to The Sixth People’s Hospital of Wenzhou from December 2018 to December 2019, whose sputum was collected and tested using SAT-TB, smear acid-fast staining method, and the BACTEC MGIT 960 system. With the MGIT 960 culture test method as the gold standard, the application value of SAT-TB, acid-fast staining, or SAT-TB combined with acid-fast staining in the diagnosis and treatment of PTB was assessed. Results. With the MGIT 960 culture as the gold standard, the sensitivity, specificity, positive predictive value, and negative predictive value of SAT-TB for the diagnosis of PTB were 57.3%, 92.5%, 84.3%, and 73.5%, respectively. The conformity was 76.8%, and the Kappa value was 0.515, suggesting a statistically significant difference ( χ 2 = 7.314 , p < 0.05 ) and a general consistency degree. Additionally, the sensitivity, specificity, positive predictive value, and negative predictive value of SAT-TB combined with sputum smear acid-fast staining were 81.3%, 86.0%, 88.4%, and 80.8%, respectively, with the MGIT 960 culture still the gold standard. The conformity and Kappa value were 83.9% and 0.672, respectively, showing no statistically significant difference ( χ 2 = 0.438 , p > 0.05 ) and a relatively high consistency degree. Conclusion. SAT-TB combined with acid-fast staining had a similar detection rate to that of the MGIT 960 culture test with a high consistency degree, which could be applied in the diagnosis of PTB efficiently and accurately.

scholarly journals Pre-Procedural Surveillance Testing for SARS-CoV-2 in an Asymptomatic Population Shows Low Rates of Positivity

2020 ◽  
Author(s):  
James A Mays ◽  
Alexander L Greninger ◽  
Keith R Jerome ◽  
John B Lynch ◽  
Patrick C Mathias
Keyword(s):  
Positive Predictive Value ◽  
Beck Depression Inventory ◽  
Predictive Value ◽  
Total Population ◽  
False Negative ◽  
Self Report ◽  
Case Group ◽  
Cross Sectional ◽  
Predictive Values ◽  
Sensitivity Specificity

Background: Depression is a common cause of mortality and morbidity worldwide. To detect depression, we compared Beck Depression Inventory scoring as a valid tool with participants self-reporting depression.Methodology: This cross-sectional study aimed to explore the diagnostic values of self-reporting in patients' with depression comparing to Beck Depression Inventory scoring in Mazandaran Persian cohort study, with a total of 1300 samples. The sample size was determined to include 155 participants through the census method. In order to increase the test power, 310 healthy participants were included in the study through random selection. In order to evaluate the diagnostic value of self-reporting, BDI-II was completed by blind interviewing to the case group as well as to another group who reported that they were not depressed, as control.Results: sensitivity, specificity, accuracy, false positive, false negative, positive and negative predictive values of self-reporting was calculated 58.4%, 79.1%,73.4%, 20.8%, 41.6%, 51.8%, and 83.2% for the total population respectively, as well as, sensitivity, specificity, accuracy, positive and negative predictive values of self-report in males were 83.3%, 77.2%, 77.1%, 43.8% and 95.6% and 53.7%, 78.1%, 71.2%, 49.2%, and 81.1% for females, respectively.Conclusion: The positive predictive value and sensitivity of self-reporting are insufficient in total population and females, and therefore self-reporting cannot detect depressed patients, but regarding to its average positive predictive value, perhaps, it can be used to identify non-depressant individuals.

scholarly journals Diagnostic Accuracy of Ziehl-Neelsen Smear Microscopy in Comparison with GeneXpert in Pulmonary Tuberculosis: A Multi-Center Study in Kandahar Province, Afghanistan

2021 ◽  
pp. 1-7
Author(s):  
Mujeeb Ahmad ◽  
Muhammad Haroon Stanikzai ◽  
Najeeb Rahimy ◽  
Abdul Wahed Wasiq ◽  
Hadia Sayam
Keyword(s):  
Pulmonary Tuberculosis ◽  
Positive Predictive Value ◽  
Diagnostic Accuracy ◽  
Negative Predictive Value ◽  
Disease Transmission ◽  
Predictive Value ◽  
Smear Microscopy ◽  
Cross Sectional ◽  
Pulmonary Tb ◽  
Kappa Value

Background: Tuberculosis (TB) is a major global health problem. The early and accurate diagnosis is crucial for disease management and to control disease transmission and the emergence of drug resistance TB. Objectives: This study was carried out to determine the diagnostic accuracy of Ziehl Neelsen (ZN) smear microscopy in comparison with GeneXpert MTB/RIF in pulmonary tuberculosis in Kandahar province, Afghanistan. Methods: This was a facility-based cross-sectional study. We scrutinized TB registers of three health facilities to include patients who had their sputum tested by both ZN smear microscopy and GeneXpert MTB/RIF. We extracted 734 patients’ data registered during January 2019 - June 2020 in a structured form. Kappa value was analyzed using SPSS version 19 software at 95% Confidence Interval (CI). We calculated sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) of ZN smear microscopy against GeneXpert MTB/RIF. Results: In comparison with GeneXpert as a reference test, ZN smear microscopy has 67.7% (95% CI:63.44%-70.74%) sensitivity and 100% (95% CI:98.74%-100.00%) specificity. The positive predictive value (PPV) and negative predictive value (NPV) were 100% and 99.89% (95% CI:99.88%-99.90%), respectively. The agreement between ZN smear microscopy and GeneXpert MTB/RIF results was moderate (70.4%) and the Kappa value was 0.45 (95% CI:0.38-0.59). Conclusion: This study has found high specificity but moderate sensitivity for the diagnosis of pulmonary TB using sputum ZN smear microscopy test. Hence, GeneXpert MTB/RIF test is more accurate and reliable for the diagnosis of pulmonary TB.

scholarly journals Foundational Statistical Principles in Medical Research: Sensitivity, Specificity, Positive Predictive Value, and Negative Predictive Value

Medicina ◽  
2021 ◽  
Vol 57 (5) ◽  
pp. 503
Author(s):  
Thomas F. Monaghan ◽  
Syed N. Rahman ◽  
Christina W. Agudelo ◽  
Alan J. Wein ◽  
Jason M. Lazar ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Medical Literature ◽  
Disease Prevalence ◽  
Positive Test Result ◽  
Predictive Values ◽  
Sensitivity Specificity ◽  
Test Result ◽  
Test Probability

Sensitivity, which denotes the proportion of subjects correctly given a positive assignment out of all subjects who are actually positive for the outcome, indicates how well a test can classify subjects who truly have the outcome of interest. Specificity, which denotes the proportion of subjects correctly given a negative assignment out of all subjects who are actually negative for the outcome, indicates how well a test can classify subjects who truly do not have the outcome of interest. Positive predictive value reflects the proportion of subjects with a positive test result who truly have the outcome of interest. Negative predictive value reflects the proportion of subjects with a negative test result who truly do not have the outcome of interest. Sensitivity and specificity are inversely related, wherein one increases as the other decreases, but are generally considered stable for a given test, whereas positive and negative predictive values do inherently vary with pre-test probability (e.g., changes in population disease prevalence). This article will further detail the concepts of sensitivity, specificity, and predictive values using a recent real-world example from the medical literature.

scholarly journals Clinical Performance of the Spot Vision Photo Screener before and after Induction of Cycloplegia in Children

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Konuralp Yakar
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Clinical Performance ◽  
High Specificity ◽  
Screening Criteria ◽  
Predictive Values ◽  
Before And After ◽  
Sensitivity Specificity ◽  
Vision Screener

Aim. To compare the clinical performance of the Spot Vision Screener used to detect amblyopia risk factors (ARFs) in children before and after induction of cycloplegia; the children were referred because they met the screening criteria of the American Association for Pediatric Ophthalmology and Strabismus (AAPOS). Methods. The Spot Vision Screener and a standard autorefractometer were used to examine 200 eyes of 100 children aged 3–10 years, before and after cycloplegia induction, in terms of ARFs. Sensitivity, specificity, and positive and negative predictive values for the detection of significant refractive errors were measured using the AAPOS referral criteria. It was explored that Spot Screener data were affected by cycloplegia. The extent of agreement between cycloplegic/noncycloplegic photoscreening data and cycloplegic autorefraction measurements was assessed using Wilcoxon and Spearman correlation analyses. Results. The Spot’s sensitivity was improved from 60.9% to 85.3% and specificity from 94.9% to 87.4% with cycloplegia compared to cycloplegic standard autorefractometer results. The positive predictive value of Spot was 75.7%, and the negative predictive value was 90.4% without cycloplegia. With cycloplegia, the positive predictive value of Spot was 63.6% and the negative predictive value was 95.8%. Conclusions. The Spot Screener afforded moderate sensitivity and high specificity prior to cycloplegia. The sensitivity and negative predictive value improved after induction of cycloplegia. Examiners should be aware of the effects of cycloplegia on their findings.

scholarly journals An assessment of chromosomal alterations detected by fluorescence in situ hybridisation in pancreatobiliary tract malignancy

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Xiaohong Pu ◽  
Hongwei Zheng ◽  
Xin Yang ◽  
Qing Ye ◽  
Zhiwen Fan ◽  
...  
Keyword(s):  
Predictive Value ◽  
In Situ Hybridisation ◽  
False Negative ◽  
Chinese Patients ◽  
Fluorescence In Situ Hybridisation ◽  
Predictive Values ◽  
Formalin Fixed Paraffin Embedded ◽  
9P21 Locus ◽  
Sensitivity Specificity

Abstract Background Using fluorescence in situ hybridisation (FISH) to detect any gain of chromosomes 3, 7, or 17 and loss of the 9p21 locus has been proven to be sensitive in the diagnosis of pancreatobiliary tumors. However, both genetic and environmental factors contribute to the pathogenesis of pancreatobiliary tumors. Therefore, it is unknown whether this method is suitable for Chinese patients with pancreatobiliary tumors. This study aims to compare the sensitivity, specificity, predictive values and accuracy of cytology, ERCP/MRCP and FISH based on Chinese patients with pancreatobiliary tumors,and to analyze differences between brushing-based and formalin-fixed paraffin-embedded (FFPE)-based FISH. Methods A total of 66 brush cytology specimens obtained during ERCP were detected by FISH and cytology test respectively to compare the sensitivity, specificity, predictive values and accuracy. Besides, FFPE-based FISH was performed on 46 corresponding paraffin sections of pancreatobiliary tumors obtained by surgical resection. Results Our findings demonstrate that FISH greatly improves diagnostic sensitivity and negative predictive value compared to ERCP/MRCP and cytology without much reduction in specificity and positive predictive value. However, our results also indicate that FFPE-based FISH could not effectively identify the false-negative of brushing-based FISH. Conclusions We believe that FISH can effectively distinguish true positive and false positive results of cytological or radiological suspicions of malignancy. However, FFPE-based FISH still does not precisely recognize the false-negative of brushing-based FISH. Both cytology-based and PPFE-based FISH had limitation in some specimens.

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