scholarly journals Xpert MTB/Rif assay in the diagnosis of smear-negative pulmonary tuberculosis: a prospective study from Nepal

2019 ◽  
Author(s):  
Priyatam Khadka ◽  
Januka Thapaliya ◽  
Ramesh Bahadur Basnet ◽  
Gokarna Raj Ghimire ◽  
Jyoti Amatya ◽  
...  

Abstract Background For improving patient care and abbreviating the disease transmission chain, speedy detection of tuberculosis and its drug-resistance with precision is crucial. Methods We analyzed, pulmonary tuberculosis (PTB) suspected, 360 smear-negative sputum from the patients attending Tribhuvan University Teaching Hospital (TUTH). The patients were selected as per the algorithm of National Tuberculosis Programme(NTP) for Xpert MTB/RIF testing. Participants’ demographic and clinical information were collected using a pre-tested questionnaire. The specimens were collected, processed directly for Xpert MTB/RIF test according to the manufacturer’s protocol. The same samples were stained using Ziehl-Neelsen technique then observed microscopically. Both findings were interpreted; rifampicin-resistant, if obtained, on Xpert testing was confirmed with Line Probe Assay. Result Of 360 smear-negative sputum samples analyzed, 85(23.61%) found positive while 3 of them were rifampicin resistance. The infection was higher in male, i.e. 60(25.3%) compared to female 25(20.3%). The age group, >45(nearly 33%) with median age 42± 21.5, were prone to the infection. During the study period, 4.6% (515/11048) sputum samples were reported as smear-positive in TUTH; consequently, with Xpert MTB/RIF assay, additional case 16.5% (n=85/515) missed on the smear microscopy, were detected—surging overall confirmed cases. Among the most occurring clinical presentations, cough and chest pain were more evident in PTB with relative-risk at 95% confident-levels i.e. 3.03(1.01-9.11) and 3.47(2.29-5.27) respectively. A higher number of new suspects (n=63) were found positive compared to previously treated suspects. The upper lobe infiltrates (36.4%) and pleural effusion (40.4%) were peculiar radiological impression noted in PTB patient. 94 MDR suspected cases were enrolled; of total suspected cases, 29 samples were found rifampicin sensitive, 1 indeterminant while 2 of them were rifampicin-resistant. However, a single rifampicin-resistant; case was detected in patient which was not MDR suspected. Conclusion Additional cases of PTB which are neglected as smear-negative on microscopy and other conventional tests can be detected with gene Xpert test. Hence, recommended to every suspect as a presumptive test could be a wise investment in diagnosis to restrict the global burden to some extent. Keywords: Xpert MTB/Rif assay, Mycobacterium tuberculosis, Line Probe Assay, MDR-TB

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Priyatam Khadka ◽  
Januka Thapaliya ◽  
Ramesh Bahadur Basnet ◽  
Gokarna Raj Ghimire ◽  
Jyoti Amatya ◽  
...  

Abstract Background In most developing countries, smear-negative pulmonary TB (SNPT) often gets missed from the diagnosis of consideration, though it accounts 30–65% of total PTB cases, due to deficient or inaccessible molecular diagnostic modalities. Methods The cross-sectional study enrolled 360 patients with clinical-radiological suspicion of SNPT in Tribhuvan University Teaching Hospital (TUTH). The patient selection was done as per the algorithm of Nepal’s National Tuberculosis Program (NTP) for Xpert MTB/RIF testing. Participants’ demographic and clinical information were collected using a pre-tested questionnaire. The specimens were collected, processed directly for Xpert MTB/RIF test according to the manufacturer’s protocol. The same samples were stained using the Ziehl-Neelsen technique then observed microscopically. Both findings were interpreted; rifampicin-resistant, if obtained, on Xpert testing was confirmed with a Line Probe Assay. Result Of 360 smear-negative sputum samples analyzed, 85(23.61%) found positive while 3(0.8%) of them were rifampicin resistance. The infection was higher in males, i.e. 60(25.3%) compared to female 25(20.3%). The age group, > 45(nearly 33%) with median age 42 ± 21.5, were prone to the infection. During the study period, 4.6% (515/11048) sputum samples were reported as smear-positive in TUTH. Consequently, with Xpert MTB/RIF assay, the additional case 16.5% (n = 85/515) from smear-negative presumptive TB cases were detected. Among the most occurring clinical presentations, cough and chest pain were positively associated with SNPT. While upper lobe infiltrates (36.4%) and pleural effusion (40.4%) were the most peculiar radiological impression noted in PTB patient. 94 multi-drug resistant(MDR) suspected cases were enrolled; of total suspects, 29(30.8%) samples were rifampicin sensitive, 1(1.06%) indeterminate, 3(3.19%) rifampicin-resistant while remaining of them were negative. 2(2.2%) MDR cases were recovered from the patient with a previous history of ATT, of total 89 previously treated cases enrolled However, a single rifampicin-resistant from the new suspects. Conclusion With an application of the assay, the additional cases, missed with smear microscopy, could be sought and exact incidence of the diseases could be revealed.


2019 ◽  
Author(s):  
Priyatam Khadka ◽  
Januka Thapaliya ◽  
Ramesh Bahadur Basnet ◽  
Gokarna Raj Ghimire ◽  
Jyoti Amatya ◽  
...  

Abstract Background In most developing countries, smear-negative pulmonary TB (SNPT) often gets missed from the diagnosis of consideration, though it accounts 30-65% of total PTB cases, due to deficient or inaccessible molecular diagnostic modalities. Methods The cross-sectional study enrolled 360 patients with clinical-radiological suspicion of SNPT in Tribhuvan University Teaching Hospital (TUTH). The patient selection was done as per the algorithm of Nepal’s National Tuberculosis Program (NTP) for Xpert MTB/RIF testing. Participants’ demographic and clinical information were collected using a pre-tested questionnaire. The specimens were collected, processed directly for Xpert MTB/RIF test according to the manufacturer’s protocol. The same samples were stained using the Ziehl-Neelsen technique then observed microscopically. Both findings were interpreted; rifampicin-resistant, if obtained, on Xpert testing was confirmed with a Line Probe Assay. Result Of 360 smear-negative sputum samples analyzed, 85(23.61%) found positive while 3(0.8%) of them were rifampicin resistance. The infection was higher in males, i.e. 60(25.3%) compared to female 25(20.3%). The age group, >45(nearly 33%) with median age 42± 21.5, were prone to the infection. During the study period, 4.6% (515/11048) sputum samples were reported as smear-positive in TUTH. Consequently, with Xpert MTB/RIF assay, the additional case 16.5% (n=85/515) from smear-negative presumptive TB cases were detected. Among the most occurring clinical presentations, cough and chest pain were positively associated with SNPT. While upper lobe infiltrates (36.4%) and pleural effusion (40.4%) were the most peculiar radiological impression noted in PTB patient. 94 multi-drug resistant(MDR) suspected cases were enrolled; of total suspects, 29(30.8%) samples were rifampicin sensitive, 1(1.06%) indeterminate, 3(3.19%) rifampicin-resistant while remaining of them were negative. 2(2.2%) MDR cases were recovered from the patient with a previous history of ATT, of total 89 previously treated cases enrolled However, a single rifampicin-resistant from the new suspects. Conclusion With an application of the assay, the additional cases, missed with smear microscopy, could be sought and exact incidence of the diseases could be revealed. Keywords: Xpert MTB/Rif assay, Mycobacterium tuberculosis, Line Probe Assay, MDR-TB, smear-negative


2019 ◽  
Author(s):  
Priyatam Khadka ◽  
Januka Thapaliya ◽  
Ramesh Bahadur Basnet ◽  
Gokarna Raj Ghimire ◽  
Jyoti Amatya ◽  
...  

Abstract Background In most developing countries, smear-negative pulmonary TB (SNPT) often gets missed from the diagnosis of consideration, though it accounts 30-65% of total PTB cases, due to deficient or inaccessible molecular diagnostic modalities. Methods The cross-sectional study enrolled 360 patients with clinical-radiological suspicion of SNPT in Tribhuvan University Teaching Hospital (TUTH). The patient selection was done as per the algorithm of Nepal’s National Tuberculosis Programme (NTP) for Xpert MTB/RIF testing. Participants’ demographic and clinical information were collected using a pre-tested questionnaire. The specimens were collected, processed directly for Xpert MTB/RIF test according to the manufacturer’s protocol. The same samples were stained using the Ziehl-Neelsen technique then observed microscopically. Both findings were interpreted; rifampicin-resistant, if obtained, on Xpert testing was confirmed with a Line Probe Assay. Result Of 360 smear-negative sputum samples analyzed, 85(23.61%) found positive while 3(0.8%) of them were rifampicin resistance. The infection was higher in males, i.e. 60(25.3%) compared to female 25(20.3%). The age group, >45(nearly 33%) with median age 42± 21.5, were prone to the infection. During the study period, 4.6% (515/11048) sputum samples were reported as smear-positive in TUTH. Consequently, with Xpert MTB/RIF assay, the additional case 16.5% (n=85/515) from smear-negative presumptive TB cases were detected. Among the most occurring clinical presentations, cough and chest pain were positively associated with SNPT. While upper lobe infiltrates (36.4%) and pleural effusion (40.4%) were the most peculiar radiological impression noted in PTB patient. 94 multi-drug resistant(MDR) suspected cases were enrolled; of total suspects, 29(30.8%) samples were rifampicin sensitive, 1(1.06%) indeterminant, 3(3.19%) rifampicin-resistant while remaining of them were negative. 2(2.2%) MDR cases were recovered from the patient with a previous history of ATT, of total 89 previously treated cases enrolled However, a single rifampicin-resistant from the new suspects. Conclusion With an application of the assay, the additional cases, missed with smear microscopy, could be sought and exact incidence of the diseases could be revealed. Keywords: Xpert MTB/Rif assay, Mycobacterium tuberculosis, Line Probe Assay, MDR-TB, smear-negative


PLoS ONE ◽  
2017 ◽  
Vol 12 (8) ◽  
pp. e0182988 ◽  
Author(s):  
Binit Kumar Singh ◽  
Surendra K. Sharma ◽  
Rohini Sharma ◽  
Vishnubhatla Sreenivas ◽  
Vithal P. Myneedu ◽  
...  

Author(s):  
Rohit Kumar ◽  
Shivendra Kumar Shahi ◽  
Rakesh Kumar ◽  
Balkrishna Mishra ◽  
Shailesh Kumar ◽  
...  

Background: The term tuberculosis describe a clinical illness, which is predominantly caused by Mycobacterium tuberculosis and less common by other species. Infection is transmitted by infected droplets through respiratory route. Early diagnosis and appropriate management is the only way to control the spread of infection. The available diagnostic tools include, smear microscopy, culture and molecular methods. Culture is the gold standard, but it takes around 2-8 weeks to get the result and smear microscopy having less sensitivity. Molecular technique especially Line probe assay can be better option because of high sensitivity and specificity, and directly clinical sample can be used, and result will be made available within same day with sensitivity pattern. Present study was designed to use of LPA for early diagnosis.Methods: Laboratory based observational study conducted in department of microbiology, IGIMS Patna and TBDC, Patna. Sputum specimens were collected from clinically suspected cases of pulmonary tuberculosis, and subjected to smear microscopy, culture and LPA.Results: During the study period, 2841 patients were diagnosed as pulmonary tuberculosis. Strain of Mycobacterium tuberculosis complex in, 12% (347) patients were rifampicin and isoniazid resistant, 4% (117) and 3% (86) patients were rifampicin and isoniazid mono-resistant respectively. We found that rpoB MUT3 was the most common mutation in gene associated with rifampicin resistant and katG MUT1gene associated with isoniazid resistant.Conclusions: Present study support the use of LPA for early diagnosis of smear positive as well as smear negative pulmonary tuberculosis cases. Resulting early diagnosis and appropriate management of patients.


1970 ◽  
Vol 26 (1) ◽  
pp. 3-6
Author(s):  
Zohra Khatun ◽  
Chandan Kumar Roy ◽  
Tuhin Sultana ◽  
Md Quddusur Rahman ◽  
AN Nashimuddin Ahmed

Light emitting diode (LED) fluorescence microscopy offers well described benefits compared with brightfield microscopy by Ziehl-Neelsen stained sputum, even which are smear negative. We evaluated the diagnostic performance of fluorescence microscopy, using novel light-emitting diode (LED) technology as an alternative to the brightfield microscopy. The objective of this study was the role of LED fluorescence microscopy in diagnosis of smear negative pulmonary tUberculosis. This is a prospective study consisted of 50 smear negative patients, who were clinically suspected cases of pulmonary tuberculosis. All samples were stained by both ZN stain and Auramine stain and as a gold standard all were cultured on Lowenstein-Jensen Media. On evaluation of all sputum samples were found negative by ZN method but by auramine stain 16%, 20%, 20% cases were found positive by conventional fluorescence microscopy (CFM), LED and culture respectively. LED fluorescence microscopy is more useful test to distinguish the smear negative cases. It also provide an effective guideline to make decisions regarding judicious use of antitubercular drug therapy. Keywords: Smear negative Sputum; LED; CFM; Culture; Pulmonary Tuberculosis DOI: http://dx.doi.org/10.3329/bjpath.v26i1.9126 BJPATH 2011; 26(1): 3-6


2012 ◽  
Vol 6 (2) ◽  
pp. 2-6 ◽  
Author(s):  
Mohammad Jobayer ◽  
SM Shamsuzzaman ◽  
Kazi Zulfiquer Mamun

Pulmonary tuberculosis is a major health problem in Bangladesh that is responsible for about 7% of total death in a year. This study was conducted to isolate and identify Mycobacterium tuberculosis from sputum and to evaluate the efficacy of PCR as a modern diagnostic tool, for diagnosis of pulmonary tuberculosis, especially in the smear negative cases. One hundred and fifty suspected pulmonary TB patients (male/ female: 97/53) were included in this study. Single morning sputum was collected from each patient and diagnostic potential of PCR was compared with staining and culture. Twenty five (16.7%) sputum were positive by ZN stained smear. Among 125 smear negative samples, 13 (10.4%) yielded growth in culture in LJ media and 21 (16.8%) samples were positive by PCR. The sensitivity and specificity of PCR in smear negative cases was 100% and 92.9% respectively. Mean detection time in PCR was 24 hours. PCR detected M. tuberculosis in 21 smear negative and 9 culture negative samples. For diagnosis of tuberculosis in smear negative cases, PCR directly from sputum was a very sensitive and accurate method. In conclusion, PCR may be done, especially in clinically suspected pulmonary tuberculosis patients who remain negative by conventional methods.DOI: http://dx.doi.org/10.3329/bjmm.v6i2.19368 Bangladesh J Med Microbiol 2012; 06(02): 2-6


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