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 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 Diagnostic performance of GeneXpert MTB/RIF assay compared to conventional Mycobacterium tuberculosis culture for diagnosis of pulmonary and extrapulmonary tuberculosis, Nepal

Narra J ◽  
2021 ◽  
Vol 1 (2) ◽  
Author(s):  
Raina Chaudhary ◽  
Sabita Bhatta ◽  
Alina Singh ◽  
Manoj Pradhan ◽  
Brijendra Shrivastava ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Predictive Value ◽  
Diagnostic Performance ◽  
Extrapulmonary Tuberculosis ◽  
Culture Method ◽  
Smear Microscopy ◽  
Early Management ◽  
Army Hospital ◽  
Conventional Culture ◽  
Sensitivity Specificity

Tuberculosis is an infectious disease caused by the Mycobacterium tuberculosis. It is a global health problem and major cause of death in resource-limited countries like Nepal. Timely diagnosis with sensitive testing methods could assist in early management of the disease. This study was conducted to compare the diagnostic performance of GeneXpert MTB/RIF and conventional acid-fast staining with M. tuberculosis culture. The study was carried out in the Department of Microbiology, Shree Birendra Army Hospital, Nepal. Samples (n=500) were tested with a GeneXpert MTB/RIF assay and acid-fast bacilli (AFB) smear microscopy. All samples were sent for M. tuberculosis conventional culture by the German-Nepal Tuberculosis Project, Kathmandu, Nepal (GENETUP). Out of a total 500 pulmonary and extrapulmonary samples tested, 97 samples were positive for M. tuberculosis by GeneXpert MTB/RIF assay. Out of the positive samples, only 95 samples were found positive by the culture method. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of AFB microscopy was 45.3%, 99.5%, 99.5% and 88.5%, respectively. The sensitivity, specificity, PPV and NPV of GeneXpert MTB/RIF was found to be 100%, 99.5%, 97.5% and 100%, respectively compared to the gold standard culture method. The GeneXpert MTB/RIF test was comparable with culture diagnosis of both pulmonary and extrapulmonary tuberculosis cases.

scholarly journals DIAGNOSTIC ACCURACY OF XPERTMTB/RIF ASSAY IN DETECTION OF PULMONARY TUBERCULOSIS AND RIFAMPICIN RESISTANCE IN COMPARISON WITH CONVENTIONAL METHODS.

2019 ◽  
pp. 1-3
Author(s):  
B.V. Ramana* ◽  
A. Srikar ◽  
P. Prakash ◽  
Abhijit Chaudhury
Keyword(s):  
Pulmonary Tuberculosis ◽  
Diagnostic Accuracy ◽  
Conventional Method ◽  
Sputum Sample ◽  
Early Morning ◽  
Rifampicin Resistance ◽  
Smear Microscopy ◽  
High Morbidity ◽  
Significant Difference ◽  
Sensitivity Specificity

Introduction: Tuberculosis is one of the oldest diseases with high morbidity and mortality. India accounts for one- fourth of the global TB burden (2.7million cases). Material and methods: A total 1056 patients were included in this study. All patients were requested to give two sputum samples, spot sputum sample (at the time of visit) and early morning sputum for mycobacterial testing. All spot samples tested with smear microscopy and Xpert MTB/Rif assay. Rifampicin resistant samples compared with conventional method. Results: Out of 1056 sputum samples GeneXpert MTB Rif assay detected positive 204 (19.3%), not detected 827 (78.31%). There is significant difference founded for positivity in spot samples and early morning sputum samples (P =0.0026). Rifampicins resistant were 8 (3.9%) andshown 100% sensitivity, specificity with Conventional method. Conclusion: For diagnosing tuberculosis and detecting Rifampicin resistance GeneXpert MTB/RIF has been especially recommended.

scholarly journals A Comparison Of Three Versus Two Sputum Smear Microscopy In A Government Medical College, Patiala, India

1970 ◽  
Vol 8 (2) ◽  
pp. 28-30
Author(s):  
J Kishan ◽  
P Kaur ◽  
A Mahajan ◽  
M Monika ◽  
K Navneet ◽  
...  
Keyword(s):  
Pulmonary Tuberculosis ◽  
Sputum Sample ◽  
Work Load ◽  
Early Morning ◽  
Control Programme ◽  
Sputum Smear ◽  
Smear Microscopy ◽  
Medical College ◽  
Two Samples ◽  
National Tuberculosis

Introduction: Under the Revised National Tuberculosis Control Programme of India, three sputum samples are examined and 2 samples positivity criteria are used for labeling the patient as sputum positive pulmonary tuberculosis. Recent studies advocate use of two samples (one spot & one morning) for diagnosis of Tuberculosis. The objective was to compare three versus two sputum smears and to study the relevance of third sputum sample for microscopy in the current practice under Revised National Tuberculosis and Control Programme. Methodology: A study of the laboratory register of the designated microscopic centre for the calendar year 2008 was undertaken. In all 9028 suspects were examined. An analysis of contribution of various sputum samples, S1 (fi rst spot sample), M (early morning) & S2 (second spot) towards diagnosis of Pulmonary Tuberculosis was undertaken. Results: Sputum smear examination results of all the patients examined during 2008 were analyzed. Twelve hundred and eighty eight patients (99.3%) were labeled as smear positive tuberculosis when three sputum samples positivity criteria was considered. By applying two samples and any smear positivity criteria 1296 (99.9%) patients were labeled as sputum smear positive. Among 1296 smears, S1 was positive in 1088 (83.8%) and M in 1293 (99.6%) patients. Early morning sample positivity yield was found higher. Conclusion: Considering 2 samples for examination with at least one morning specimen and one sample positivity criteria, the work load on laboratory can be reduced by 1/3rd without affecting case detection rate. DOI: http://dx.doi.org/10.3126/saarctb.v8i2.5898 SAARCTB 2011; 8(2): 28-30

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 ACCURACY OF XPERTMTB/RIF ASSAY IN DETECTION OF PULMONARY TUBERCULOSIS AND RIFAMPICIN RESISTANCE IN COMPARISON WITH CONVENTIONAL METHODS..

2019 ◽  
pp. 1-3
Author(s):  
B.V. Ramana* ◽  
A. Srikar ◽  
P. Prakash ◽  
Abhijit Chaudhury
Keyword(s):  
Pulmonary Tuberculosis ◽  
Diagnostic Accuracy ◽  
Conventional Method ◽  
Sputum Sample ◽  
Early Morning ◽  
Rifampicin Resistance ◽  
Smear Microscopy ◽  
High Morbidity ◽  
Significant Difference ◽  
Sensitivity Specificity

Introduction: Tuberculosis is one of the oldest diseases with high morbidity and mortality. India accounts for one- fourth of the global TB burden (2.7million cases). Material and methods: A total 1056 patients were included in this study. All patients were requested to give two sputum samples, spot sputum sample (at the time of visit) and early morning sputum for mycobacterial testing. All spot samples tested with smear microscopy and Xpert MTB/Rif assay. Rifampicin resistant samples compared with conventional method. Results: Out of 1056 sputum samples GeneXpert MTB Rif assay detected positive 204 (19.3%), not detected 827 (78.31%). There is significant difference founded for positivity in spot samples and early morning sputum samples (P =0.0026). Rifampicins resistant were 8 (3.9%) andshown 100% sensitivity, specificity with Conventional method. Conclusion: For diagnosing tuberculosis and detecting Rifampicin resistance GeneXpert MTB/RIF has been especially recommended.

scholarly journals Comparative Evaluation between Detection of Mycobacterium Tuberculosis Complex in Samples of Extra Pulmonary Tuberculosis using Gene Xpert MTB/RIF Assay and Ziehl-Neelsen Staining in a Tertiary Care Hospital

2020 ◽  
Vol 5 (6) ◽  
pp. 1139-1141
Author(s):  
Om Prakash Bharati ◽  
Manoj Kumar ◽  
Ashok Kumar Sharma
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Pulmonary Tuberculosis ◽  
Predictive Value ◽  
Mycobacterium Tuberculosis Complex ◽  
Care Hospital ◽  
Tuberculosis Complex ◽  
Extra Pulmonary Tuberculosis ◽  
Two Samples ◽  
Extra Pulmonary ◽  
Sensitivity Specificity

Tuberculosis is a global problem and incidence of extra pulmonary tuberculosis is increasing day by day. Diagnosis of extra pulmonary tuberculosis is a little bit difficult than pulmonary tuberculosis.Aim and Objective: The aim of this study is to correlate between isolates of mycobacterium in GeneXpert and ZiehlNeelsen (ZN) staining. It also detects the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of GeneXpert assay and ZN staining.This prospective study was carried out in the Department of Microbiology, RIMS, Ranchi, Jharkhand. Seventy two samples from suspected patients of Extra pulmonary tuberculosis were taken. These samples were processed for test in GeneXpert assay, ZN staining and MGIT culture. Mycobacterium tuberculosis complex isolated from culture was taken as gold standard and compared with result of GeneXpert and ZN staining. Result: Out of 72 samples, detection rate of GeneXpert, MGIT and ZN staining were 27.77%, 26.38% and 18%. The sensitivity, specificity, PPV and NPV of ZN staining and GeneXpert were 63.15%, 98.11%, 92.3%, 88.13% and 94.73%, 96.22%, 90%, 98% respectively. GeneXpert is a rapid and easy method for extra pulmonary tuberculosis diagnosis. It not only detect the bacilli but also diagnose rifampicin drug resistance. This method prompts in diagnosis and treatment.

scholarly journals Effective use of Penicillin to Improve Culture Yield for Mycobacterium tuberculosis

2019 ◽  
Vol 6 ◽  
pp. 103-107
Author(s):  
Sneha Pradhan ◽  
Gokarna Raj Ghimire ◽  
Shova Shrestha
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Pulmonary Tuberculosis ◽  
Sputum Sample ◽  
Early Morning ◽  
National Tuberculosis ◽  
Effective Use ◽  
Culture Yield

Objective: To compare LJ media and LJ media with penicillin for the growth of Mycobacterium tuberculosis and contamination, in pulmonary tuberculosis (PTB) suspected patients. Methods: A total of 300 PTB suspected cases at National Tuberculosis center (NTC) for analyzed for culture and contamination. Early morning sputum samples were collected in sterile leak-proof falcon tube. Digestion, decontamination and homogenization of sputum were done using NALC-NaOH (Modified Petroff method). The sputum sample was processed on LJ media and penicillin added LJ media and incubated at 37. Cultures were examined after 8 weeks. Results: All the PTB suspected cases were compared in LJ media and LJ media with penicillin, 29.7% (89) were positive, 21% (63) were contaminated on LJ media whereas 41% (123) were positive, 3.7 % (11) were contaminated on penicillin added LJ media. Also, 25 (8%) were 1+ grading, 14 (4.7%) were 2+ grading, whereas 81 (27%) and 45 (15%) were 3+ grading LJ + Penicillin and LJ media respectively. Conclusion: Contamination was reduced by 17.3% with the addition of penicillin to LJ media. And isolation of total positive cultures was enhanced by 11.3%.

scholarly journals PERFORMANCE OF XPERT MTB/RIF ASSAY FOR DETECTION OF M.TB IN PULMONARY AND EXTRA-PULMONARY SAMPLES IN INDIAN PATIENTS

2017 ◽  
Vol 14 (1) ◽  
pp. 7-13
Author(s):  
Shamma Shetye ◽  
P. Chheda ◽  
A Lad ◽  
S Matkar
Keyword(s):  
Predictive Value ◽  
Liquid Culture ◽  
Culture Method ◽  
Turnaround Time ◽  
Smear Microscopy ◽  
Reference Laboratory ◽  
Clinical Specimens ◽  
Extra Pulmonary ◽  
Mgit Culture ◽  
Sensitivity Specificity

Introduction: Conventional methods like Ziehl-Neelsen (ZN) staining and liquid culture have been the mainstay for diagnosis of Tuberculosis (TB). The gold standard Liquid Culture method has a longer turnaround time. In the wake of the TB catastrophe, newer rapid and easily accessible methods of detection are the need of the hour. A molecular method like the Xpert MTB/RIF assay has revolutionized the early and rapid diagnosis of TB. Objective of the current study was to assess the performance and utility of Xpert MTB/RIF assay for the diagnosis of M. tuberculosis in pulmonary and extra-pulmonary clinical specimens in a large Indian reference laboratory.Methodology: The reference methods used were MGIT Liquid Culture system and ZN smear microscopy. Our study was performed in Global Reference Laboratory, Metropolis Healthcare, Mumbai, India for a period of 18 months with consecutive one thousand and forty two (518 Pulmonary + 524 extra-pulmonaryspecimens) clinical specimens obtained from the patients with clinical suspicion of tuberculosis. Diagnostic performance (sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the three methods were calculated with standard formulae.Results: In comparison to MGIT Liquid culture, sensitivity of Xpert MTB/RIF assay for pulmonary and extra pulmonary specimens were 87.18% and 68.92%, respectively while in comparison to ZN smear microscopy the sensitivity of Xpert MTB/RIF assay for pulmonary and extra pulmonary specimens were 92.67% and 83.81%, respectively.Conclusion: Our study concludes that in combination with the MGIT culture, Xpert MTB/RIF assay will significantly improve the detection rate of MTB bacteria.SAARC J TUBER LUNG DIS HIV/AIDS, 2017; XIV(1), page: 7-13

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