Project description:Extra-pulmonary TB (EPTB) is difficult to diagnose due to paucibacillary nature of disease. Current study evaluated accuracy of Truenat MTB and MTB-Rif Dx (TN), for detection of Mycobacterium tuberculosis and resistance to rifampicin. Samples were collected from 2103 treatment naive adults with presumptive EPTB, and tested by smear microscopy, liquid culture (LC) (MGIT-960) and GeneXpert MTB/RIF (GX) (Microbiological Reference Standards, MRS). TN results were compared to MRS and Composite Reference Standards (CRS, Microbiology, histopathology, radiology, clinical features prompting decision to treat, response to treatment). CRS grouped patients into 551 confirmed, 1096 unconfirmed, and 409 as unlikely TB. TN sensitivity and specificity was 73.7% and 90.4% against GX. Against LC, Overall sensitivity of GX was 67.6%, while that of TN was 62.3%. Highest sensitivity by TN was observed in pus samples (89%) and highest specificity (92%) in CSF samples, similar to GX. TN sensitivity was better in fluid and biopsy samples and slightly inferior for lymph node aspirates compared to GX. TN sensitivity for RIF resistance detection was slightly superior to GX. TN and GX results were further compared to Clinical Reference Standards. TN detected 170 TB patients initiated on treatment missed by GX, while GX detected 113 such patients missed by TN. Of 124 samples with RIF resistance discordance between GX and TN, GX reported 103/124 as sensitive, 3/124 as indeterminate and 18 as resistant (13/18 samples had low/very low DNA load) while TN reported RIF resistance indeterminate in 103/111 low/very low DNA load samples. Due to paucibacillary nature of EPTB samples, culture yield was poor and phenotypic drug susceptibility testing failed to resolve the discordance. The study establishes TN at par with GX and can be utilized for quick and accurate diagnosis of EPTB.
Project description:BACKGROUND. Novel rapid diagnostics for active tuberculosis (TB) are required to overcome the time delays and inadequate sensitivity of current microbiological tests that are critically dependent on sampling the site of disease. Multiparametric blood transcriptomic signatures of TB have been described as potential diagnostic tests. We sought to identify the best transcript candidates as host biomarkers for active TB, extend the evaluation of their specificity by comparison with other infectious diseases, and to test their performance in both pulmonary and extrapulmonary TB. METHODS. Support vector machine learning, combined with feature selection, was applied to new and previously published blood transcriptional profiles in order to identify the minimal TB‑specific transcriptional signature shared by multiple patient cohorts including pulmonary and extrapulmonary TB, and individuals with and without HIV-1 coinfection. RESULTS. We identified and validated elevated blood basic leucine zipper transcription factor 2 (BATF2) transcript levels as a single sensitive biomarker that discriminated active pulmonary and extrapulmonary TB from healthy individuals, with receiver operating characteristic (ROC) area under the curve (AUC) scores of 0.93 to 0.99 in multiple cohorts of HIV-1-negative individuals, and 0.85 in HIV-1-infected individuals. In addition, we identified and validated a potentially novel 4-gene signature comprising CD177, haptoglobin, immunoglobin J chain, and galectin 10 that discriminated active pulmonary and extrapulmonary TB from other febrile infections, giving ROC AUCs of 0.94 to 1. CONCLUSIONS. Elevated blood BATF2 transcript levels provide a sensitive biomarker that discriminates active TB from healthy individuals, and a potentially novel 4-gene transcriptional signature differentiates between active TB and other infectious diseases in individuals presenting with fever. FUNDING. MRC, Wellcome Trust, Rosetrees Trust, British Lung Foundation, NIHR.
Project description:Rapid, cost-effective, and sensitive diagnostic assays are essential for global tuberculosis (TB) control, especially in high TB burden, resource-limited settings. The current study was designed to evaluate diagnostic accuracy of Truenat MTB-Rif Dx (MolBio) in children less than 18 years of age, with symptoms suggestive of TB. Gastric aspirate, induced sputum, and broncho-alveolar lavage samples were subjected simultaneously to AFB-smear, GeneXpert MTB/RIF, liquid culture (MGIT-960) and Truenat MTB-Rif Dx. The index-test results were evaluated against microbiological reference standards (MRS). Truenat MTB-Rif Dx had a sensitivity of 57.1%, specificity of 92% against MRS. The sensitivity and specificity of the Truenat MTB-RIF Dx compared with liquid culture was 58.7% and 87.5% while GeneXpert MTB/RIF was 56% and 91.4%. The performance of both GeneXpert MTB/RIF and Truenat MTB-Rif Dx are comparable. Result of our study demonstrates that Truenat MTB-Rif can aid in early and efficient diagnosis of TB in children.
Project description:A 23-year-old indigenous Guatemalan man presented in 2016 to our clinic in Sololá, Guatemala, with 10 months of recurrent neck swelling, fevers, night sweats and weight loss. Previously, he had sought care in three different medical settings, including a private physician-run clinic, a tertiary private cancer treatment centre and, finally, a rural government health post. With assistance from our institution's accompaniment staff, the patient was admitted to a public tertiary care hospital for work-up. Rifampin-susceptible tuberculosis was diagnosed, and appropriate treatment was begun. The case illustrates how low tuberculosis recognition among community health workers and health system segmentation creates obstacles to appropriate care, especially for patients with limited means. As a result, significant diagnostic and treatment delays can occur, increasing the public health burden of tuberculosis.
Project description:ObjectiveTo compare the diagnostic performance of laboratory assays on the ultrasound-guided core needle biopsy samples for diagnosis of extra-pulmonary tuberculosis (EPTB) in HIV-positive and HIV-negative patients.MethodsA total of 217 patients suspected to have EPTB underwent lesion biopsy from 2017 to 2020. Results of laboratory tests on the biopsy and non-biopsy samples were collected with clinical data for retrospective analysis of test utility. The calculated diagnostic accuracy of the tests was stratified according to the specimen types and HIV status.ResultsThe cohort contained 118 patients with a final positive diagnosis of extrapulmonary tuberculosis (EPTB group, 54.4%) and 99 finally diagnosed as without TB (non-EPTB group, 45.6%). The risk factor for EPTB was HIV co-infection (OR 2.22, 95% CI 1.17-4.28, p = 0.014). In biopsy samples, GeneXpert (Xpert) showed higher sensitivity (96.6% [91.6-98.7], p < 0.0001) than culture (56.1% [47.0-64.9]). Regardless of HIV status, Xpert had the highest sensitivity (>95%) and specificity (nearly 100%) of any methods. In non-biopsy samples, only T-SPOT.TB (T-SPOT) showed higher sensitivity than culture (90.9% [62.3-99.5] vs 35.3% [17.3-58.7], p = 0.0037). Furthermore, the sensitivities of Xpert were lower in non-biopsy samples (60.0% [23.1-92.9], p = 0.022) than in biopsy samples (100% [86.7-100]). Even in smear-negative biopsy samples, Xpert still had higher sensitivity than culture and retained high specificity (100% [95.7-100]).ConclusionSuperior performance of Xpert in diagnosing EPTB was observed regardless of HIV status and specimen types. Nevertheless, the biopsy samples still substantially facilitated the accurate diagnosis of extrapulmonary tuberculosis.
Project description:BackgroundThe World Health Organization endorsed Truenat MTB rapid molecular assay in 2020 and recommended additional in-country evaluation studies before uptake. We evaluated the accuracy and operational feasibility of Truenat MTB assay (Truenat) in comparison with GeneXpert Ultra and culture.MethodsIn a cross-sectional study of 250 presumptive TB patients, participants were requested to provide a sputum sample on the day of their visit to the clinic. The sputum sample was homogenized and a portion was tested using GeneXpert Ultra as per the routine standard procedure and the other portion was tested using Truenat assay at the clinic laboratory. The second sample portion was processed for Concentrated Fluorescent smear Microscopy (CFM), LJ, and MGIT cultures. Truenat sensitivity and specificity were compared to GeneXpert Ultra and culture. Test performance characteristics and operational feasibility assessment data through interview of the study laboratory staff were also collected and summarized as proportions and percentages.ResultsOf the 250 participants recruited in the study, the sensitivity and specificity of Truenat was n/N (%, 95%CI); 66/82 (80.5, 70.2-88.4) and 156/159 (98.1, 94.5-99.6) when compared with Ultra, 50/64 (89.3, 66.0-87.4) and 166/180 (92.2, 87.2-95.6) when compared with LJ, 58/71 (81.7,70.7-89.8) and 131/138 (94.9, 89.8-97.9) when compared to MGIT culture and 59/73 (80.8, 69.9-89.1) and 159/169 (94.1,89.3-97.1) when compared to LJ and/or MGIT culture. The sensitivity of Truenat was lower, 14/23 (60.9, 40.6-82.8) among smear-negative compared to 45/50 (90.0, 78.1-96.6) among smear-positive participants but not different by HIV status. There were no special training needs especially among laboratory personnel with previous GeneXpert /molecular test experience, 19/242 (7.8%) error/invalid, and 12 (17,4%) uninterpretable/indeterminate results mainly for rifampicin resistance determination. However, there were 3 (3.5%) of GeneXpert Ultra indeterminate results.ConclusionAmong presumptive TB patients in Uganda, the Truenat assay has high sensitivity and specificity. The Truenat assay has acceptable operational feasibility attributes when compared with the GeneXpert Assay.
Project description:Pediatric extrapulmonary tuberculosis (EPTB) is a diagnostic challenge. A new immunochemistry based MPT64 antigen detection test has shown improved sensitivity compared to current laboratory tests. The aim of this study was to implement and validate the test performance in a resource limited African setting. Presumptive pediatric (0-18 y) EPTB patients were prospectively enrolled at Mbeya Zonal Referral Hospital, and followed to the end of treatment or until a final diagnosis was reached. Specimens from suspected sites of infection were subject to routine diagnostics, GeneXpert MTB/RIF assay and the MPT64 test. The performance of the tests was assessed using mycobacterial culture as well as a composite reference standard. 30 patients were categorized as TB cases, 31 as non-TB cases and 2 were uncategorized. In the TB group, the three most common infections were adenitis (30%), peritonitis (30%) and meningitis (20%). The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of the MPT64 test was 92%, 88%, 87%, 92% and 90%, respectively. Mortality was equally high among TB/non-TB cases (23% vs 21%), and malnutrition was the main comorbidity among TB cases. The MPT64 test was implementable in the routine diagnostics in a low-resource setting and improved the diagnosis of pediatric EPTB.
Project description:ObjectivesBacteriological confirmation of extrapulmonary tuberculosis (EPTB) is challenging for several reasons: the paucibacillary nature of the sample; scarce resources, mainly in middle and low-income countries; the need for hospitalization; and unfavorable outcomes. We evaluated the diagnostic role of respiratory specimen examination prospectively in a cohort of patients with presumptive EPTB.MethodsFrom July 2018 to January 2019, in a tuberculosis (TB)/HIV reference hospital, a cohort of 157 patients with presumed EPTB was evaluated. Xpert® MTB/RIF Ultra or a culture-positive result was considered for bacteriologically confirmed TB.ResultsOut of 157 patients with presumptive EPTB, 97 (62%) provided extrapulmonary and respiratory specimens and 60 (38%) extrapulmonary specimens only. Of the 60 patients with extrapulmonary samples, 5 (8%) were positive. Of those with respiratory and extrapulmonary samples, 27 (28%) were positive: 10 in both the respiratory and extrapulmonary samples, 6 in the extrapulmonary sample only, and 11 in the respiratory sample only. A respiratory specimen examination increased by 6-fold the chance of bacteriological confirmation of TB (odds ratio = 5.97 [1.11-47.17]).ConclusionWe conclude that respiratory samples should be examined in patients with presumptive EPTB.
Project description:BackgroundTruenat is a novel molecular assay that rapidly detects tuberculosis (TB) and rifampicin-resistance. Due to the portability of its battery-powered testing platform, it may be valuable in peripheral healthcare settings in India.MethodsUsing a microsimulation model, we compared four TB diagnostic strategies for HIV-negative adults with presumptive TB: (1) sputum smear microscopy in designated microscopy centers (DMCs) (SSM); (2) Xpert MTB/RIF in DMCs (Xpert); (3) Truenat in DMCs (Truenat DMC); and (4) Truenat for point-of-care testing in primary healthcare facilities (Truenat POC). We projected life expectancy, costs, incremental cost-effectiveness ratios (ICERs), and 5-year budget impact of deploying Truenat POC in India's public sector. We defined a strategy "cost-effective" if its ICER was <US$990/year-of-life saved (YLS). Model inputs included: TB prevalence, 15% (among those not previously treated for TB) and 27% (among those previously treated for TB); sensitivity for TB detection, 89% (Xpert) and 86% (Truenat); per test cost, $12.63 (Xpert) and $13.20 (Truenat); and linkage-to-care after diagnosis, 84% (DMC) and 95% (POC). We varied these parameters in sensitivity analyses.ResultsCompared to SSM, Truenat POC increased life expectancy by 0.39 years and was cost-effective (ICER $210/YLS). Compared to Xpert, Truenat POC increased life expectancy by 0.08 years due to improved linkage-to-care and was cost-effective (ICER $120/YLS). In sensitivity analysis, the cost-effectiveness of Truenat POC, relative to Xpert, depended on the diagnostic sensitivity of Truenat and linkage-to-care with Truenat. Deploying Truenat POC instead of Xpert increased 5-year expenditures by $270 million, due mostly to treatment costs. Limitations of our study include uncertainty in Truenat's sensitivity for TB and not accounting for the "start-up" costs of implementing Truenat in the field.ConclusionsUsed at the point-of-care in India, Truenat for TB diagnosis should improve linkage-to-care, increase life expectancy, and be cost-effective compared with smear microscopy or Xpert.
Project description:Introduction Although the incidence of tuberculosis (TB) in Japan has been decreasing yearly, Japan remains ranked as an intermediate-burden country for TB. Objective This study aims to investigate the current situation of head and neck extrapulmonary TB (EPTB) diagnosed in our department. Methods We retrospectively reviewed the clinical records of 47 patients diagnosed with EPTB in the head and neck in our department between January 2005 and December 2014. The extracted data included sex and age distribution, development site, chief complaint, presence or absence of concomitant active pulmonary TB (PTB) or history of TB, tuberculin skin test (TST) results, interferon-gamma release assay (IGRA) results, and duration from the first visit to the final diagnosis of EPTB. Results The subjects consisted of 20 men and 27 women, and age ranged from 6 to 84 years. The most common site was the cervical lymph nodes (30 patients), with the supraclavicular nodes being the most commonly affected (60%). Histopathological examination was performed on 28 patients. TST was positive in 9 out of 9 patients and the IGRA was positive in 18 out of 19 patients. We observed concomitant PTB in 15 out of the 47 patients. Mean duration from the first visit to the final diagnosis of EPTB was 56 days. Conclusion The clinical symptoms of TB, especially those in the head and neck region, are varied. Otolaryngologists should be especially aware of the extrapulmonary manifestations of TB to ensure early diagnosis and treatment from the public health viewpoint.