Mycobacterium Tuberculosis Rifampicin Research Articles

Effectiveness of Systematic Screening and Treatment of Tuberculosis in Prison in Thailand.

The global incidence of tuberculosis (TB) in prison is 5 to 70 times greater than that in the general population. The systematic screening and treatment of TB in prison benefit TB control and treatment outcomes. However, no study has supported this in Thailand. Here, we evaluated the effectiveness of long-term, continuous, systematic screening for TB control. We conducted a retrospective study in Suratthani Central Prison, Thailand, using annual TB screening from 2016 to 2020. A positive TB screening was defined as having any TB symptoms or chest radiography abnormality. We collected sputum smear and Xpert® Mycobacterium tuberculosis/rifampicin (MTB/RIF) results from those inmates with positive screening results. Bacteriologically confirmed TB was defined as a positive sputum smear or M. tuberculosis detected by Xpert assay. Inmates with clinically diagnosed TB were also eligible for this study. Those inmates diagnosed with active TB were sent to an isolation zone in prison and received anti-TB medicine using directly observed therapy and were monitored by pulmonologists during the treatment course via telemedicine. Of 18,965 TB screening events, 175 patients were diagnosed with TB. The 5-year prevalence was 922 per 100,000 inmates. The relative reduction in TB prevalence was 60.5% from 2016 to 2020. Overall, 94.3% of TB patients were successfully treated (sum of patients cured and treatment completed). Three TB patients died during the 5-year study period. All occurred in 2016. The systematic screening and treatment of TB in inmates effectively reduced the prevalence and mortality in Suratthani Central Prison. The success rate of treatment in this prison has been consistently high.

Implication of Negative GeneXpert Mycobacterium tuberculosis/Rifampicin Results in Suspected Tuberculosis Patients: A Research Study.

GeneXpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) is a conceptually helpful tool for establishing tuberculosis (TB) disease. Negative results from the GeneXpert test do not exclude the possibility of diagnosing non-tuberculous mycobacteria lung disease (NTMLD) as a chronic pulmonary disease. When a patient is diagnosed on a clinical basis, and there is no bacteriological evidence of TB, it is necessary to consider NTM as one of the causes of disease with TB-like symptoms. The prevalence of non-tuberculous mycobacteria (NTM) disease is rising globally, but its diagnosis is still delayed and often misdiagnosed as multidrug-resistant TB (MDR-TB). This study highlights the implication of negative GeneXpert MTB/RIF results in suspected TB patients who conducted mycobacteria culture and detected the incidence of NTMLD. In this experimental study, the performance of GeneXpert MTB/RIF-negative results with those of mycobacteria cultures and lung abnormalities among suspected TB patients in a referral hospital in Indonesia were evaluated. From January to August 2022, 100 sputum samples from suspected chronic pulmonary TB patients with GeneXpert MTB/RIF assay-negative results were cultured in Lowenstein-Jensen medium, and the implication among negative GeneXpert result MTB/RIF assay. 7% were confirmed to have MTB and 1% had NTM by culture assay. Moreover, 34% were diagnosed with clinical TB and treated with anti-TB drugs. For patients with negative assay results of GeneXpert MTB/RIF regarding clinically suspected chronic TB infection, further diagnostic tests to determine the causative agents of the lung abnormalities should be carried out.

Comparison of Xpert MTB RIF (G4) With Xpert MTB (Ultra) in Diagnosis of Mycobacterium Tuberculosis in Clinical Samples

Abstract Background: Tuberculosis (TB) continues to be a major cause of morbidity and mortality worldwide. The main strategy to fight the pandemic is the development of rapid, accurate diagnostic tests, which helps to reduce the time for initiation of therapy. In 2010, WHO recommended the use of Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) (G4), which is a cartridge-based semi-automated nucleic acid amplification test (NAAT) as a primary test with an aim to improve the detection of MTB. Later on, to improve the diagnostic efficacy, the new and improved cartridges called Xpert Ultra were introduced in 2017. Materials and Methods: One thousand and sixty-nine clinical samples were utilized for the study for microscopy, culture, and NAATs (Xpert MTB/RIF G4 and Ultra). The samples were randomly allocated. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated while assuming trace results as positive and negative in two separate scenarios. Results: The sensitivity of Xpert MTB/RIF Ultra cartridge was higher (100%) than Xpert MTB/RIF G4 cartridge (95.23%) and the specificity of Ultra cartridge was lower (71.79%) when compared to G4 cartridge (91.63%). However, the specificity of Xpert Ultra cartridge improved by reclassifying the “trace” interpretation as negative (89.1%). The NPV was 100% and 99.09% for Xpert Ultra cartridge and the Xpert G4 cartridge, respectively, and did not change by reclassifying the “trace” interpretation as negative. In contrast, the PPV varied greatly between the two tests, 26.66% for Xpert Ultra cartridge and 66.66% for Xpert G4 cartridge. The PPV of Xpert Ultra cartridge was improved to 48.48% by including “trace” samples in the negative pool. Conclusion: Xpert Ultra and G4 shows good performance as a first line diagnostic test. Caution should be exercised when interpreting ‘trace’ results in a country like India without parallel confirmatory tests like microscopy and culture. Data is limited on this newly incorporated value assigned in the automated report. Conducting further studies on results interpreted as ‘trace’ will help in improving the guidelines and as well as utilisation of such tests.

Assessment of the Diagnostic Utility of GeneXpert Mycobacterium tuberculosis/Rifampicin (MTB/RIF) Assay in the Suspected Cases of Tuberculous Meningitis.

Tuberculous meningitis (TBM) is a manifestation of extrapulmonary tuberculosis (EPTB) caused by Mycobacterium tuberculosis (MTB). The central nervous system is involved in about 1%-2% of all current tuberculosis (TB) cases and about 7%-8% of all EPTB. if not treated early, TBM leads to a high rate of neurological sequelae and mortality. This study aimed to assess the diagnostic performance of the GeneXpert MTB/rifampicin (RIF) assay in patients with TBM. A total of 100 suspected TBM cases were enrolled from various departments at tertiary care hospital, Bhopal, Madhya Pradesh, India, and classified as definite, possible, or probable TBM. The clinical samples were tested for microbiological and other cerebrospinal fluid(CSF) testing. Out of 100 cases, 14 (14%) were classified as definite TBM, 15 (15%) were having probable TBM, and 71 (71%) were having possible TBM.Out of a total of 100 participants, all were negative for acid-fast bacilli (AFB) staining. Of the 100 cases, 11 (11%) were positive by mycobacterium growth indicator tube (MGIT) culture, of which only four (36.36%) were positive by GeneXpert MTB/RIF. GeneXpert MTB/RIF detected three (3%) cases that were negative by MGIT culture. Ten (90.9%) of the 11 MGIT-positive culture isolates were found to be RIFsensitive while one (9.1%) was found to be RIF resistant. Three cases tested positive/sensitive by the GeneXpert MTB/RIF but negative by MGIT culture. Six (85%) of the seven GeneXpert MTB/RIF positive cases were RIF sensitive while one (15%) was RIF resistant. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy were 36.36% (95% Confidence Interval (CI) (10.93% to 69.21%)), 96.63% (95% CI (90.46% to 99.30%)), 57.14% (95% CI (25.50% to 83.85%)), 92.47% (95% CI (88.70% to 95.06%)) and 90% (95% CI (82.38% to 95.10%)) for GeneXpert MTB/RIF assay, compared with MGIT culture as the reference standard. Our study found that the sensitivity is lower when compared to culture, so using GeneXpert MTB/RIF alone is not recommended. Overall performance of GeneXpert MTB/RIF assay is noteworthy. The GeneXpert MTB/RIF assay is a potentially accepted test for obtaining an earlier diagnosis, and if it tested positive, the treatment should begin immediately. However, culture must be performed in GeneXpert MTB/RIF negative cases.

Diagnosis of tuberculous pleural effusion in a tertiary care hospital of central India: The role of xpert Mycobacterium tuberculosis/rifampicin.

In India, 15%-20% of tuberculosis (TB) cases are categorized as extra-pulmonary TB, and tuberculous pleural effusion (TPE) is the second-most common type after tuberculous lymphadenitis. However, the paucibacillary nature of TPE makes its diagnosis challenging. As a result, relying on empirical anti-TB treatment (ATT) based on clinical diagnosis becomes necessary for achieving the best possible diagnostic outcome. The study aims to determine the diagnostic utility of Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) for the detection of TB in TPE in high incidence setting of Central India. The study enrolled 321 patients who had exudative pleural effusion detected through radiological testing and were suspected of having TB. The medical procedure of thoracentesis was conducted to collect the pleural fluid, which was then subjected to both the Ziehl-Neelsen staining and Xpert MTB/RIF test. The patients who showed improvement after receiving anti-tuberculosis treatment (ATT) were considered the composite reference standard. The sensitivity of smear microscopy was found to be 10.19%, while that of the Xpert MTB/RIF method was 25.93% when compared to the composite reference standard. The accuracy of clinical diagnosis was measured using receiver operating characteristics based on clinical symptoms, and it was found to be 0.858 (area under the curve). The study shows that Xpert MTB/RIF has significant value in diagnosing TPE, despite its low sensitivity of 25.93%. Clinical diagnosis based on symptoms was relatively accurate, but relying on symptoms alone is not enough. Using multiple diagnostic tools, including Xpert MTB/RIF, is crucial for accurate diagnosis. Xpert MTB/RIF has excellent specificity and can detect RIF resistance. Its quick results make it useful in situations where a rapid diagnosis is necessary. While it should not be the only diagnostic tool, it has a valuable role in diagnosing TPE.

Uncommon manifestation of disseminated tuberculosis with metastatic skin abscesses in an immunocompromised adult patient: A case report

Background: Cutaneous lesions account for less than 2% of all extrapulmonary manifestations of tuberculosis (TB). Metastatic tuberculous abscesses (tuberculous gummas), uncommon forms of cutaneous TB, typically result from the bacillus spreading hematogenously from the main site of infection to the subcutaneous tissue when the body's cell mediated immunity is compromised and present with one or more non-tender and fluctuant subcutaneous nodules. Case Presentation: A 51-year-old male presented with dry cough of one month duration associated with loss of appetite, easy fatigability and vomiting of ingested matter. He had left armpit and lower back skin swellings of similar duration. Physical findings were remarkable for whitish coat over the dorsal part of the tongue, crepitation over the lower two-third of bilateral posterior chest, and non-tender fluctuant masses over the left axilla and lower back region. Chest X-ray revealed multiple bilateral air space nodules and abdominopelvic U/S showed numerous hypoechoic splenic lesions. Urine lipoarabinomannan and Xpert MTB/RIF (mycobacterium tuberculosis/rifampicin) assay from the axillary skin abscess were positive for MTB. He was started on anti-tuberculous therapy and showed marked improvement after a month of follow up. Conclusion: It is worth considering the uncommon manifestations of tuberculosis including metastatic skin abscesses in the appropriate clinical context, to avoid misdiagnosis and underreporting in high tuberculosis burden countries. We strongly advise the utilization of Xpert MTB/RIF assay and/or urine lipoarabinomannan for the diagnosis of different forms of tuberculosis including cutaneous TB in HIV positive patients, especially in the absence of sputum for microbiologic tests, like in our patient

Trends of Xpert MTB/RIF in the diagnosis of Mycobacterium tuberculosis and rifampicin resistance in Southwest Nigeria: A 4-year retrospective study

Objectives: In recent years, there has been an increased uptake of Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) for the diagnosis of tuberculosis (TB), with added benefits for detecting rifampicin-resistant TB (RR-TB). We set out to determine the trends in notification of MTB and RR-TB over 4 years in a tertiary hospital in Southwest Nigeria. Materials and Methods: This is a retrospective analysis of single early morning sputum/gastric washing sample for presumed TB in a tertiary health center between January 2016 and December 2019. Xpert MTB/RIF was used to detect (MTB) and RR-TB. Results: The mean age of the 4625 presumptive TB patients was 43.4 (18.8) years, with the majority aged 31–45 (30.6%). Males totaled 2247 (49.6%). Human immunodeficiency virus (HIV) coinfection was found in 756 (16.7%) of them. Using the Xpert MTB/RIF assay, the overall MTB notification was 12.9% (584/4526) and was associated with HIV status, P < 0.001. MTB notification trends increased from 5.6% in 2016 to 23.8% in 2019, P < 0.001. The overall yield of RR-TB was 7.5%. The proportion of RR-TB from TB cases declined from 28% in 2016 to 4.6% in 2019. Forty-two of the 44 cases of the RR-TB (42/572; 7.3%, [95% CI: 5.31, 9.75]) were new cases, with TB treatment failure and relapse cases accounting for 10.1% (2/11; 10.1%, [95% CI: 0.35, 42.5]) of all RR-TB cases (P < 0.01). RR-TB was associated with being older than 45 years (adjusted odds ratio = 2.046, [95% CI: 1.046, 4.004]). HIV infection status and gender had no effect on RR-TB status. Conclusion: This study found an increase in MTB detection with Xpert MTB/RIF utilization. Ages >45 years have 2–4-fold increased risk of developing RR-TB and should be targeted for drug resistance prevention.

Evaluation of xpert Mycobacterium tuberculosis rifampicin for tuberculosis diagnosis in a reference laboratory.

The Xpert Mycobacterium tuberculosis Rifampicin (MTB-RIF) is a technological innovation that presents precision and speed in the diagnosis of tuberculosis (TB). The study aimed to evaluate the performance of Xpert MTB/RIF in the TB diagnosis and compare its results with those of culture, species identification, Antimicrobial Susceptibility Testing (AST), and rpoB gene sequencing of discordant results in AST, used for the diagnosis of TB in a reference laboratory. Cross-sectional descriptive study of pulmonary and extrapulmonary samples requesting Xpert MTB/RIF and culture for TB diagnosis from 2015 to 2019 at Adolfo Lutz Institute-São Paulo/Brazil. The analysis was performed with Epi-Info 7.2.1, presenting the distribution of frequencies and, for comparative analyses, Pearson's Chi-square test and Fisher's exact test were used, considering P ≤ 0.05 as statistically significant. For variables agreement, the Kappa method was used. A total of 1575 pulmonary and extrapulmonary samples were analyzed using Xpert MTB/RIF and culture, of which 293 were positive for the MTB Complex in both methodologies with a sensitivity of 94.55%; specificity of 95.97%; accuracy 95.69%; positive predictive value 85.53%; negative predictive value 98.59%, substantial agreement by Kappa 0.87, and detection sensitivity even at lower levels of bacillary load (P < 0.05). The Xpert MTB/RIF and AST showed concordant results (P < 0.05). The study brings forward that the Xpert MTB/RIF shows substantial agreement with the results of culture and AST, contributing to the diagnosis of TB and the rapid detection of resistance. The sequencing of resistant cultures in Xpert MTB/RIF and sensitivity in AST identified the H526N mutation, characterized by a low level of resistance to RIF.

Frequency of rifampicin-resistant mycobacterium tuberculosis by GeneXpert MTB/RIF assay and its correlates among 2605 probable tuberculosis patients in upper Egypt

RationaleGeneXpert MTB/RIF (Mycobacterium tuberculosis/rifampicin) assay is a method for detecting rifampicin resistance (RR-MTB) in suspected samples in less than 2 hours with high sensitivity and specificity yield. This study aimed to use the GeneXpert MTB/RIF assay to determine the frequency of RR-MTB and to study the possible influencing correlates associated with positive results. Subjects and methodsThis is a retrospective cross-sectional study of patients who visited TB clinic in 5 years (2016–2021). According to the data sheet of the patients, all the collected specimens were divided into 2 parts one for diagnosis by Ziehl–Neelsen stain and the other part for GeneXpert analysis. GeneXpert was also used to look for evidence of RR. ResultsOut of the 2605 total samples screened, 718 (27.6%) tested positive for MTB on GeneXpert assay; of them 633 (88.4%) were sensitive to Rifampicin, 83 (11.6%) were resistant to Rifampicin and 2 cases were undetermined. Factors contributing to RR-MTB were: smoker/ex-smoker, with 2.5 times more risk (p = 0.013.0, p = 0.001); recurrence cases had a 4-fold increased risk (p < 0.001); patients with very low M. tuberculosis detected on the GeneXpert MTB/RIF test were 8 times more likely to have RR-TB (P = 0.004). ConclusionThis study disclosed a high-rate MTB in Egyptian probable TB cases. Smoking, recurrence and cases with a very low M. tuberculosis burden noticed on the GeneXpert MTB/RIF test had augmented risk of RR-TB.

Prevalence of Rifampicin-Resistant Mycobacterium Tuberculosis by CBNAAT in a Tertiary Care Hospital of West Bengal, India

Background: Tuberculosis (TB) remains one of the commonest infectious diseases in India, where control is difficult due to the emergence of multi-drug-resistant TB (MDR-TB). The rifampicin resistance (RR) is an important surrogate marker of MDR-TB. Aims and Objectives: The aim of this article is to determine the prevalence of RR-TB among all symptomatic presumptive TB patients by cartridge-based nucleic acid amplification test (CBNAAT) in our institution. Materials and Methods: A retrospective cross-sectional study was conducted from January 2018 to December 2020 in the Directly Observed Treatment (DOT) center of a tertiary care hospital. All presumptive cases of pulmonary TB patients coming to the DOT center were subjected to CBNAAT by GeneXpert Mycobacterium tuberculosis rifampicin (MTB/RIF) (Cepheid). Data were collected from a data-extraction sheet from registration books and analyzed using SPSS version 20. Fisher’s exact test was applied to examine the association between categorical variables and P-value less than 0.05 was considered significant. Results: A total of 6171 presumptive TB patients were included in the study. The overall prevalence of TB was 1590 (25.77%) in all age groups. The prevalence of RR-TB among all confirmed TB cases was 10.75% (171/1590) with the majority being males (130 cases). The prevalence of RR cases among new and previously treated was 3.1% and 36.34%, respectively, which were statistically significant (P &lt; 0.05). Conclusion: We found that RR-TB is still much prevalent in our area, and it was significantly higher in previously treated cases. The CBNAAT is a good molecular assay method for rapid detection of TB and also for the detection of RR-TB.

Role of GeneXpert or CBNAAT in Diagnosing Tuberculosis

About a quarter of the world's population is infected with tuberculosis (TB), with new infection occurring every second. The global burden, particularly with multidrug resistance, is also increasing simultaneously and has become a major health challenge. Earlier and improved case detection, including smear-negative disease, often associated with HIV co-infection, and expanded capacity to diagnose multidrug-resistant TB are global priorities for TB control. Conventional laboratory methods are slow and cumbersome. Hence, novel technologies for rapid detection are the focus of TB research and development. GeneXpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) is one of them, currently unique in its simplification of molecular testing with amplification and detection based on real-time polymerase chain reaction. Xpert MTB/RIF detects MTB as well as RIF resistance directly from sputum within 2 h. This article focuses on the significance of new diagnostic test for TB.

Efficacy of CBNAAT versus Adenosine Deaminase in Fluids in Extrapulmonary Tuberculosis

Introduction: Tuberculosis though primarily, is a pulmonary disease, it may manifest as Extrapulmonary Tuberculosis (EPTB). The gold standard method for the diagnosis of extrapulmonary tuberculosis is blood culture. Increased activity of Adenosine Deaminase (ADA) is observed in tuberculosis. Cartridge-based Nucleic Acid Amplification Test (CBNAAT) or Gene Xpert Mycobacterium tuberculosis/ rifampicin (MTB/RIF) is based on Real-Time Polymerase Chain Reaction (RTPCR). Extrapulmonary tuberculosis may present with varied features, may mimic malignancy, and pose a diagnostic challenge. Aim: To assess and compare the efficacy of Cartridge-based Nucleic Acid Amplification Test (CBNAAT) and Adenosine Deaminase (ADA) in cases with extrapulmonary tuberculosis. Materials and Methods: This cross-sectional study was conducted on presumptive cases of extrapulmonary tuberculosis presenting in Department of Medicine at People’s Hospital, Bhopal, Madhya Pradesh, India, from November 2019 to August 2021. All the patients were subjected to detailed history and clinical examination including series of blood and radiological investigations. Apart from this, ADA analysis and CBNAAT was done in all the cases and were treated accordingly. The two tests were compared using Chi-square test. The p-value &lt;0.05 were considered statistically significant. Results: Male predominance was observed and with no statistical difference in age (p-value=0.09) and gender (p-value=0.21). Out of 19 cases of Tubercular Meningitis (TBM) from total 125, ADA was raised in 10 (52.6%) cases, whereas out of 42 Tubercular Pleural Effusion (TBPE) and 24 Tubercular Peritonitis (TBP) cases, ADA was raised in 26 (61.9%) and 4 (16.7%) cases, respectively. Out of 19 cases of TBM, CBNAAT was positive in 4 (21.1%) cases, whereas out of 42 TBPE and 24 TBP cases, CBNAAT positivity was documented in 8 (19%) and 2 (8.3%) cases, respectively. Overall, the sensitivity of ADA was higher for detection of TBM and TBPE as compared to CBNAAT but the specificity of CBNAAT was higher for all the extrapulmonary tuberculosis. Overall diagnostic accuracy of ADA was higher (61.6%) as compared to CBNAAT (43.2%) for detection of extrapulmonary tuberculosis. Conclusion: Extrapulmonary tuberculosis poses diagnostic challenge and thus for diagnosis, evaluation of each component i.e., history, physical examination, blood investigations, fluid analysis, ADA estimation, and CBNAAT is important. Relying solely on single diagnostic modality may be associated with low diagnostic yield, and thus each step of patient assessment must be given equal preference so as to improve the diagnostic yield.

Unlocking the health system barriers to maximise the uptake and utilisation of molecular diagnostics in low-income and middle-income country setting

BackgroundEarly access to diagnosis is crucial for effective management of any disease including tuberculosis (TB). We investigated the barriers and opportunities to maximise uptake and utilisation of molecular diagnostics in...

Diagnostic yield of endoscopic ultrasound-guided fine-needle aspiration of tubercular lymphadenitis using combination of cytology and Gene Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF) genes.

Diagnostic yield of an automated molecular test, Gene Xpert Mycobacterium tuberculosis/rifampicin (MTB/RIF), was evaluated in this study to simultaneously detect the MTB gene and resistance to rifampicin (RIF) on cytology samples acquired via endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNAC) in suspected tubercular lymphadenitis. Microscopy, cytology, Gene Xpert MTB/RIF assay data on Acid-fast bacillus (AFB), and traditional culture of lymph nodes were retrospectively analyzed. Thirty-one patients (median age 33.5years, inter-quartile range [IQR] 21-66, 18, 58% female) presented with fever (28, 90%), dysphagia (2, 7%), and recurrent subacute intestinal obstruction (1, 3%). Gene Xpert showed higher sensitivity (30, 97%) compared to the other tests: cytology (23, 77%; odds ratio [OR] 8.8, 95% confidence interval [CI] 1.0-76.9; p = 0.05), AFB smears (12, 39%; OR 50, 95% CI 5.9-420.4; p = 0.00001), and conventional culture (4, 13%; OR 188.5, 95% CI 19.7-1796.3; p = 0.0000). We conclude that Gene Xpert MTB/RIF test on EUS-guided FNAC samples is very useful to diagnose tubercular lymphadenitis.

Comparison evaluation between gene Xpert Mtb/Rif and multiplex PCR for rapid diagnosis of mycobacterium tuberculosis.

To compare the efficacy of Gene Xpert mycobacterium tuberculosis-rifampicin and multiplex polymerase chain reacton for the detection of mycobacterium tuberculosis and Rifampicin resistance. The cross-sectional validation study was conducted at the Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from March to October 2018, and comprised mycobacterium tuberculosis-positive rifampicin-resistant and rifampicin-susceptible samples, with the latter acting as negative controls. Gene Xpert mycobacterium tuberculosis-rifampicin assasy and multiplex polymerase chain reacton were applied simultaneously and compared with gold standard mycobacterium growth indicator tube 960. Data was analysed using SPSS 24. Of the 192 samples, 84(44%) were culture-positive rifampicin-resistant and 108(56%) were culture-positive rifampicin-susceptible. Overall, 84(44%) were found positive. Gene Xpert mycobacterium tuberculosis-rifampicin assay detected all 84(100%) rifampicin-resistant samples, while multiplex polymerase chain reacton detected 44(52.3%) such samples. Sensitivity, specificity, positive predictive value and negative predictive value of Gene Xpert were 100% each respectively, while the corresponding values for multiplex polymerase chain reacton were 52%, 100%, 100% and 72% respectively. Molecular detection of mycobacterium tuberculosis and resistance by Gene Xpert and multiplex polymerase chain reacton simultaneously was found to be a rapid and cost-effective method.

THE DIAGNOSTIC VALUE OF CONVENTIONAL TUBERCULOSIS DIAGNOSTIC PROCEDURE COMPARED WITH GENE X-PERT MTB/RIF: A CROSS-SECTIONAL STUDY

Objectives: The objectives of the study were to evaluate the diagnostic value of conventional tuberculosis (TB) diagnostic procedure compared with Gene X-pert Mycobacterium tuberculosis/rifampicin (MTB/RIF). &#x0D; Methods: A cross-sectional study conducted from January to December 2018. The accuracy of conventional TB diagnostic procedure: TB screening, chest X-ray, and sputum Ziehl-Neelsen (ZN) staining was compared to Gene X-pert MTB/RIF using 2 × 2 table. p &lt; 0.05 were taken as statistically significant. The collected data were processed using Statistical Package for the Social Science software version 26.0.&#x0D; Results: A total of 117 participants suspected TB was found 44 (37.60%) confirmed TB. Among the suspected TB cases, 86 (73.50%) were male and 31 (26.50%) were female with the mean age of 43.86±16.47 years. The sensitivity and specificity of TB screening (prolonged cough) were 84.00% and 12.00%, respectively. Chest X-ray had the sensitivity and specificity (91.00%) and (10.00%). The sensitivity and specificity of sputum ZN were 57.00% and 99.00%.&#x0D; Conclusions: Conventional TB diagnostic procedure has a high accuracy compared with Gene X-pert MTB/RIF. Therefore, it is still recommended as a TB diagnostic procedure routinely in era of Gene X-pert MTB/RIF, especially in Primary Health Care with limited settings.

Accuracy and consequences of using trial-of-antibiotics for TB diagnosis (ACT-TB study): protocol for a randomised controlled clinical trial

IntroductionOver 40% of global tuberculosis case notifications are diagnosed clinically without mycobacteriological confirmation. Standard diagnostic algorithms include ‘trial-of-antibiotics’—empirical antibiotic treatment given to mycobacteriology-negative individuals to treat infectious causes of symptoms...

Drug sensitivity patterns in Xpert-positive spinal tuberculosis: an observational study of 252 patients.

To evaluate the sensitivity patterns of anti-tubercular drugs in Xpert MTB-positive spinal tuberculosis (TB) patients and to formulate the guidelines for early start of empiric anti-tubercular treatment (ATT) in MDR-TB spine based on resistance pattern in this large series. It was a cross-sectional observational study of 252 consecutive patients who were Xpert MTB-proven spinal TB cases with retrospective analysis of prospective data. The Xpert MTB/RIF (Mycobacterium tuberculosis/rifampicin) assay was used to diagnose spinal TB and RIF resistance. All patients underwent drug sensitivity testing (DST) to 13 commonly used anti-tubercular drugs using BACTEC MGIT-960 system. The drug sensitivity pattern of primary and secondary anti-tubercular drugs was recorded and compared. The DST study revealed 110 (43.6%) cases of multi-drug resistant (MDR-resistance to both isoniazid and rifampicin) and 24 (9.5%) cases of non-MDR-TB spine. The widespread resistance was found for both isoniazid (91%) and rifampicin (85%), followed by streptomycin (61.9%). The least resistance was found for kanamycin, amikacin and capreomycin and no resistance found for clofazimine. The Xpert MTB/RIF assay is an efficient technique for the rapid diagnosis of spinal TB and suspected MDR-TB; however, it is recommended to do culture and DST in all patients with spinal TB to guide the selection of appropriate second-line drugs when required. In cases of non-availability of culture and DST, it is suggested to use data from large series such as this to plan the best empirical ATT regimen. These slides can be retrieved under Electronic Supplementary Material.

Detection of Rifampicin Resistance among Patients with Tuberculosis using GeneXpert MTB/RIF Assay: A Retrospective Study

Introduction: Tuberculosis (TB) remains one of the major cause of death worldwide, and the leading causes of mortality in developing countries like India. Smear microscopy has certain limits as it requires 10,000 bacilli/mL for positivity, culture methods takes longer turnaround time of around 6-8 weeks. The recent advancement like Genexpert Mycobacterium tuberculosis/Rifampicin (MTB/RIF) Assay, which has more accuracy and analysis where it detects MTB and RIF resistance in smear negative including immunosuppressive patients even with a volume of 138 cfu (colony forming units)/mL in less than two hours. World Health Organisation (WHO) also recommended new Cartridge Based Nucleic Acid Amplification Test (CB-NAAT) on 2010 and named as GeneXpert system for diagnosis of TB. Aim: To evaluate the patterns of RIF Resistance by GeneXpert as a Rapid and primary screening test in TB patients. Materials and Methods: Both pulmonary and extra pulmonary samples were subjected to AFB (Acid Fast Bacilli) smear microscopy before being tested for GeneXpert MTB/RIF Assay. MTB detected samples were further tested at National Institute for Research in Tuberculosis (NIRT) to confirm RIF resistance and to find out associated resistance to Isoniazid and other second line drugs like fluroquinolones, kanamycin, capreomycin and amikacin. All statistical analysis were performed using Statistical Package for the Social Sciences (SPSS) version 15.0. Results: A total of 8140 samples were tested for CB-NAAT, MTB was not detected in 4414 samples, MTB detected and RIF Sensitive in 3554 samples, MTB detected and RIF resistance in 172 samples. Among these RIF Resistant samples 97% were retreatment patients and the primary drug resistance was less common. HIV/TB co-infected contributes to 1% of resistance and there was no gender preponderance. RIF mono-resistance was found in majority of patients. Conclusion: Genexpert has higher specificity for early detection of RIF resistance as a surrogate marker of MDR-TB to initiate early treatment and prevent transmission of Multi Drug Resistance (MDR) strains.

Sputum culture and drug sensitivity testing outcome among X-pert Mycobacterium tuberculosis/rifampicin-positive, rifampicin-resistant sputum: A retrospective study — Not all rifampicin resistance is multi-drug resistant

ObjectiveRifampicin-resistant (RR) tuberculosis (TB) on X-pert Mycobacterium tuberculosis/rifampicin (MTB/Rif) is assumed to be a surrogate for multi-drug resistant (MDR) TB. Following an RR result, a second specimen was taken for confirmatory culture and drug-susceptibility testing (DST). This study compared the initial diagnostic X-pert MTB/RIF result with the confirmatory DST in a high human immunodeficiency virus (HIV) seroprevalence setting. DesignRecords analysing demographics, HIV serostatus, prior TB treatments, and DST results were retrospectively reviewed. ResultsOf 604 patients with X-pert MTB/RIF RR, 374 (61.9%) had DST and were included. The mean age was 36.9 years and 82% were HIV infected. Following DST, MDR was confirmed in 49% and Rif mono-resistant (RMR) TB in 36%. Amongst RMR TB, 84% were HIV-infected, and amongst those with CD4 < 50 versus those 50–350 cells/mm3 RMR TB was noted in 51% versus 33%, respectively (P = 0.012). Primary DR was diagnosed in 43% (61% MDR and 33% RMR). ConclusionRifampicin resistance detected on a diagnostic X-pert MTB/Rif assay did not always predict MDR. Rifampicin mono-resistance is emerging amongst those with HIV co-infection and low CD4 counts (<50 cells/mm3). Research is needed to reduce the number of drugs and treatment durations for RMR TB.