Method For Diagnosis Of Tuberculosis Research Articles

Impact of the Stool-Based Xpert Test on Childhood Tuberculosis Diagnosis in Selected States in Nigeria.

In Nigeria, most children with tuberculosis (TB) present at primary health clinics where there are limited personnel skilled in collecting appropriate respiratory specimens from those who cannot produce sputum. KNCV Nigeria, in collaboration with the National Tuberculosis Control Program, implemented a modified simple, one-step (SOS), stool-based Xpert MTB/RIF method for diagnosis of TB in children who cannot expectorate sputum. We evaluated the impact of its implementation on childhood TB diagnosis. A cross-sectional study was conducted across 14 selected states using secondary data of children presumed to have TB. Stool was collected from children presumed to have TB and processed using Xpert. Out of 52,117 presumptive TB cases, 52% were male and 59.7% were under 5 years old. A total of 2440 (5%) cases were diagnosed with TB, and 2307 (95%) were placed on treatment. Annual TB notifications increased significantly after the introduction of the stool-based Xpert test when compared to those in the pre-implementation period. Increasing contributions from stool testing were observed throughout the implementation period, except in 2020 during the COVID-19 era. Overall, stool Xpert testing improved childhood TB notification in the studied states. Interventions aimed at awareness creation, capacity building, and active case finding improved the performance of the test.

Evaluation of the performance of InnowaveDX MTB/RIF for the detection of Mycobacterium tuberculosis complex and rifampicin resistance

Objective: To evaluate the performance of Mycobacterium tuberculosis and rifampicin resistance mutation detection kit (InnowaveDX MTB/RIF, referred to as "InnowaveDX") in diagnosing tuberculosis and rifampicin resistance using sputum samples. Methods: From June 19, 2020 to May 16, 2022, patients with suspected tuberculosis were prospectively and consecutively enrolled in Hunan Provincial Tuberculosis Prevention and Control Institute, Henan Provincial Hospital of Infectious Diseases and Wuhan Jinyintan Hospital. A total of 1 328 patients with suspected tuberculosis were finally included. According to the inclusion and exclusion criteria, 1 035 pulmonary tuberculosis patients (357 were confirmed tuberculosis cases and 678 were clinically diagnosed tuberculosis cases) and 180 non-tuberculosis patients were finally included. Sputum samples were collected from all patients for routine sputum smear acid-fastness tests, mycobacterial culture and drug susceptibility testing. Moreover, the diagnostic value of Xpert®MTB/RIF (referred to as "Xpert") and InnowaveDXin detecting tuberculosis and rifampicin resistance was evaluated. Clinical diagnosis and culture results of Mycobacterium tuberculosis were used as reference standards to assess tuberculosis diagnosis, and phenotypic drug sensitivity and Xpert were used as reference standards to assess rifampicin resistance. The sensitivity, specificity, positive predictive value and negative predictive value of the two methods for tuberculosis diagnosis and rifampicin resistance were analyzed. The consistency of the two techniques was analyzed usingkappa test. Results: Taking clinical diagnosis as the reference standard, the detection sensitivity of InnowaveDX [58.0% (600/1 035)] was higher than that of Xpert [51.7% (535/1 035)] in 1035 patients with pulmonary tuberculosis, and the difference was statistically significant (P<0.001). In 270 pulmonary tuberculosis patients with culture-positive pulmonary tuberculosis identified as M.tuberculosis-complex, the positive rates of InnowaveDX and Xpert were both high [99.6%(269/270)and 98.2%(265/270), respectively] and there was no statistical difference. In culture-negative patients with pulmonary tuberculosis, the sensitivity of InnowaveDX was 38.8% (198/511), which was higher than that of Xpert (29.4%, 150/511), and the difference was statistically significant (P<0.001). Taking phenotypic drug-susceptibility testing (DST) as reference, the sensitivity of InnowaveDX to rifampicin resistance was 99.0% (95%CI: 94.7%-100.0%) and the specificity was 94.0%(95%CI: 88.5%-97.4%). With Xpert as the reference, the sensitivity and specificity of InnowaveDX were 97.1% (95%CI: 93.4%-99.1%) and 99.7% (95%CI: 98.4%-100.0%), respectively, and the kappa value was 0.97 (P<0.001). Conclusions: InnowaveDX show a high sensitivity for detecting Mycobacterium tuberculosis, especially in pulmonary tuberculosis patients with a clinical diagnosis and negative culture results. It also showed high sensitivity in detecting rifampicin resistance with DST and Xpert as reference respectively. InnowaveDX is an early and accurate diagnostic tool for TB and drug-resistant TB, particularly suitable for application in low- and middle-income countries.

Safe and sensitive detection of ESAT6 in non-infectious clinical samples via an aptamer-based qPCR strategy for tuberculosis diagnosis

Tuberculosis (TB) is one of the leading cause of infection-related deaths worldwide. Conventional diagnostic methods for TB require infectious samples and are time-consuming. In this study, we aimed to develop an aptamer-based qPCR (Apta-qPCR) assay to diagnose TB safely and rapidly. The assay uses a single-stranded DNA aptamer with affinity for a TB biomarker, ESAT6, and molecular beacon capable of hybridizing to the aptamer. Apta-qPCR enables aptamer-mediated detection of ESAT6 via qPCR, wherein the aptamer serves as both a target recognition agent and template for quantification. This diagnostic method achieved a desirable detection limit of 2.03 nM in buffer and 2.56 nM in serum-spiked conditions with high reproducibility and reliability. In addition, the diagnostic performance was verified in a clinical application using human serum samples from normal controls and patients with active TB. The assay showed 50.0% sensitivity, 91.7% specificity, and 78.1% accuracy, similar to sputum smear microscopy, which is currently the most used method for TB diagnosis. Importantly, this assay has an advantage over smear microscopy in that it reduces the risk of infection by avoiding the use of sputum-containing infectious pathogens.

A comparative study of ultrasound-guided puncture biopsy combined with histopathology and Xpert MTB/RIF in the diagnosis of lymph node tuberculosis.

Cervical tuberculous lymphadenitis (CTBL) is a disease often ignored in clinical work, and pathology and Xpert MTB/RIF (Xpert) are the commonly used methods for tuberculosis diagnosis. This study aimed to compare ultrasound-guided puncture biopsy combined with histopathology and Xpert in the diagnosis of lymph node tuberculosis. A total of 217 patients highly suspected for CTBL were retrospectively enrolled. All patients underwent ultrasound-guided puncture sampling. All samples were subjected to pathological examination and Xpert test. The sensitivity and specificity of the two methods were compared for all samples. The kappa value was calculated to assess the consistency of the pathological examination and Xpert test using comprehensive diagnosis as the gold standard. Receiver operating characteristic curves of the pathological examination, Xpert test, and their combination were generated, and the areas under the curve (AUCs) were calculated to compare the diagnostic value of the three methods. The sensitivity and specificity of the pathological diagnosis of CTBL were 70.1 and 100%, respectively. The sensitivity and specificity of Xpert for CTBL diagnosis were 82.5 and 97.5%, respectively. The results of the pathological examination and Xpert test showed poor consistency in the diagnosis of CTBL, with a kappa value of 0.388. The AUC of the pathological diagnosis of CTBL was 0.850 (95% CI: 0.796-0.895), whereas that of Xpert was 0.900 (95% CI: 0.852-0.936), and the difference was statistically significant (P = 0.0483). The AUC of pathological examination combined with Xpert for the diagnosis of CTBL was 0.956 (95% CI: 0.920-0.979), and the difference between pathological examination combined with Xpert for the diagnosis of CTBL was statistically significant compared with pathological examination and Xpert alone, respectively (both P < 0.001). The diagnostic efficiency of Xpert test is higher than that of pathological examination, but its sensitivity is still not ideal for clinical diagnosis. According to this study, the consistency of Xpert test and pathological diagnosis is poor, and the combination of Xpert test and pathological diagnosis can significantly increase the diagnostic efficiency.

A Novel Tuberculosis Prediction Model by Extracting Radiological Features Present in Chest X-ray Images Using Modified Discrete Grey Wolf Optimizer Based Segmentation

In 2018, an invariant numbers ranging from 10 million people suffered from Tuberculosis (TB) approximately that has remained quite stable in recent years, based on the WHO 2019 survey report. This infection rate differs invariable among countries, from less than 5 to more than 500 new infections per 1,00,000 people each year, with a global average of around 130. Around 1.2 million HIV negative deaths existed in 2018. If this prevailing disease were diagnosed earlier, the death rate would have been under control, however sophisticated testing techniques tend to be cost prohibitive of wider acceptance. Some of the most important methods for TB diagnosis include thoracic X-ray image interpretation through image processing by the identification of various structures on thoracic X-rays and anomaly assessment is an important stage in computer-aided diagnosis systems. Chest form and size may contain indications for serious disorders such as pneumothorax, pneumoconiosis, tuberculosis and emphysema. Substantial work might have contributed to simplify diagnosis through implementing various statistical strategies to medical images, minimizing overtime and dramatically lowering overhead costs. In addition, recent advances in deep learning have provided magnificent results in the detection of images in different fields, but their use in diagnose TB remains limited. Thus, this work focuses on the development of a novel approach in disease detection. The concepts presented in this work are placed into practice and linked to current literature. We also proposed an automatic approach in conventional poster anterior chest X-rays for TB identification and diagnosis. We use the chest X-ray image with modified discrete grey wolf optimizer for segmentation techniques to eradicate abnormal areas and shape abnormality. We extract various features from the X-ray image with a shear let extraction that allows the image to be classified as normal or abnormal, based on a deep learning classifier, via the improved residual VGG net CNN with big data. Using Shenzhen Hospital Chest X-ray data set we test the efficiency of our system. The suggested technique has competitive results with comparatively shorter training period and greater precision depending on Masientropy based discrete gray wolf optimizer segmentation with an improved residual VGG net CNN. All the simulations are carried out in a mat lab environment.

Aptamer Detection of Mycobaterium tuberculosis Mannose-Capped Lipoarabinomannan in Lesion Tissues for Tuberculosis Diagnosis

Tuberculosis (TB) is the leading infectious cause of mortality worldwide. However, the diagnosis of TB, especially extrapulmonary TB (EPTB) diagnosis from lesion tissues, remains a challenge. Nucleic acid aptamers are analogous to antibodies and have advantages of easier modification, high specificity, and affinity. Mannose-capped lipoarabinomannan (ManLAM) is a unique surface lipoglycan component or constantly released from mycobacterium tuberculosis (M.tb) cell wall, which makes it a perfect candidate biomarker for TB diagnosis. Our present study aims to establish M.tb ManLAM aptamer-based immunohistochemistry (IHC) method for TB diagnosis. We performed TB diagnosis using 263 formalin-fixed paraffin-embedded tissue samples including 213 TB samples (pulmonary TB (PTB) and EPTB), and 8 samples from latent TB infection (LTBI) high risk subjects, and 42 samples from other non-TB patients with ManLAM aptamer-based IHC and routine laboratory TB diagnostic methods parallelly. The sensitivity and specificity of the ManLAM aptamer-based IHC were 86.38% and 92.86%, with much higher sensitivity than those of mycobacterial culture (9.66%) and acid-fast staining (AFS) (43.01%) and comparability to Interferon-gamma Release Assay (IGRA) (84.38%) and GeneXpert (79.31%). High agreement between ManLAM based-IHC and IGRA or GeneXpert for TB diagnosis were observed. Furthermore, ManLAM aptamer-based IHC combination with other routine TB laboratory diagnostic methods significantly increased the sensitivity up to 88.64%–97.92%. As our knowledge, this is the first report about aptamer-based IHC for disease diagnosis. Thus, ManLAM aptamer-based IHC has potentials for TB diagnosis, including PTB, and EPTB, and assists the diagnosis of LTBI with high effectiveness, feasibility, and easy production.

False-Positive Mycobacterium tuberculosis Detection: Ways to Prevent Cross-Contamination.

The gold standard method for diagnosis of tuberculosis is the isolation of Mycobacterium tuberculosis through culture, but there is a probability of cross-contamination in simultaneous cultures of samples causing false-positives. This can result in delayed treatment of the underlying disease and drug side effects. In this paper, we reviewed studies on false-positive cultures of M. tuberculosis. Rate of occurrence, effective factors, and extent of false-positives were analyzed. Ways to identify and reduce the false-positives and management of them are critical for all laboratories. In most cases, false-positive is occurring in cases with only one positive culture but negative direct smear. The three most crucial factors in this regard are inappropriate technician function, contamination of reagents, and aerosol production. Thus, to reduce false-positives, good laboratory practice, as well as use of whole-genome sequencing or genotyping of all positive culture samples with a robust, extra pure method and rapid response, are essential for minimizing the rate of false-positives. Indeed, molecular approaches and epidemiological surveillance can provide a valuable tool besides culture to identify possible false positives.

Diagnostics and treatment of scrofuloderm

Scrofuloderm is a rare manifestation of cutaneous tuberculosis. The article describes a clinical case of secondary scrofuloderm in a 35-year-old man. The case demonstrates significant and irreversible cosmetic defects of scrofuloderm as well as importance of timely use of effective methods for diagnosis of tuberculosis (molecular genetic and histological tests, multi-slice computed tomography of the chest) and modern approaches to tuberculosis therapy based on the drug sensitivity pattern.

A recent update of the diagnostic methods for tuberculosis and their applicability in Indonesia: a narrative review

Tuberculosis (TB) is a major global problem, especially with the high prevalence of HIV-TB co-infection. Delayed diagnosis and continual transmission contribute to high mortality in Indonesia, which has the third highest incidence of TB in the world, after China and India. Therefore, early diagnosis is needed to reduce the number of cases and to administer therapy to prevent the transmission of bacteria. The diagnosis of TB remains a challenge in clinical practice due to poor sensitivity and the requirement of skilled staff in microscopic tests, the slow growth Mycobacterium in culture, and the low number of bacilli present in extrapulmonary TB. Despite being the golden standard for TB diagnosis, cultures require 2–8 weeks to grow. Other methods for diagnosing TB include interferon-gamma release assays and serologic tests such as the tuberculin skin test. Recently, the World Health Organization recommended the GeneXpert MTB/RIF assay for diagnosing TB. This review presents the current state of TB epidemiology and various methods for TB diagnosis. In particular, the paper provides an in-depth discussion about the GeneXpert MTB/RIF assay that has been made available recently in selected tertiary hospitals in Indonesia.

Late diagnosis of multidrug-resistant tuberculosis in a child at Dr George Mukhari Academic Hospital, Ga-Rankuwa, South Africa: A case report.

IntroductionSouth Africa has one of the top ten tuberculosis burdens in the world, only lagging behind countries with significantly larger populations. Increased awareness of extrapulmonary tuberculosis, specifically spinal tuberculosis, is necessary, because of the HIV epidemic.Case presentationThis report describes the case of a 9-year-old male patient who was suspected of having multidrug-resistant (MDR) tuberculosis, based on failure to recover clinically and radiologically after 6 months on first-line anti-tuberculosis treatment. Pus samples were sent to an accredited academic laboratory for histopathology, microscopy, culture, line-probe assay (MTBDRplus assay) and phenotypic MGIT 960 drug susceptibility tests. Second-line MDR tuberculosis treatment was introduced. Clinical, radiological, physical processes and more laboratory tests were conducted to document whether or not there was improvement in the patient.Management and outcomeAfter laboratory diagnosis of MDR tuberculosis, the patient was started on MDR tuberculosis treatment. The patient started improving remarkably after the introduction of anti-tuberculosis treatment and rehabilitation, although he also required surgery to stabilise the spine. Neurological improvement was observed in the patient and he fully recovered.DiscussionAlthough the diagnosis of spinal MDR tuberculosis may not be achieved easily by culture, the well-known gold standard method of tuberculosis diagnosis, it is of great importance to rapidly initiate an effective anti-tuberculosis treatment of drug-resistant strains to reduce the deformity of the spine.

Efficacy of Xpert MTB/RIF Assay in the Diagnosis of Smear Negative HIV Seropositive Pulmonary Tuberculosis Patients

Background: Tuberculosis (TB) is the most common presenting illness and leading cause of death among people living with HIV(PLHIV). Diagnosis of TB among PLHIV is challenging as false negative results are common with direct microscopy (DM) and culture takes long time. WHO (2013) recommended Xpert MTB/RIF assay as an initial test for diagnosis of TB in PLHIV. Methods: The present study was conducted on 142 HIV seropositive patients who were clinically suspected to have TB. The sputum specimens obtained from these patients were divided into two parts; one was processed by DM and the other was used for Xpert MTB/RIF assay. Result: Of the 142 HIV seropositive patients, 90(63.3%) were in the age group of 15-40 years and majority 91(64.08%) were males. Out of 142 sputum specimens collected from these patients, only 5(3.52%) were positive by DM and 31(21.83%) by Xpert MTB/RIF assay. Statistically the difference between the two was significant (p value <0.005). Xpert MTB/RIF assay showed rifampicin resistant in 2(6.45%) specimen. Of the 137 smear negative specimens, Xpert MTB/RIF assay gave positive result in 27 (19.70%). Thus, the sensitivity, specificity, PPV, NPV of the Xpert MTB/RIF assay in comparison to DM was 80% (95%CI=37.6- 96.4), 80.29% (95%CI=72.8-86.1), 12.90% (95%CI=4.21-30.76), 99.09%(95%CI=94.3-99.9) respectively. Conclusion: Xpert MTB/RIF assay was found to be a sensitive, specific and rapid method for diagnosis of TB and rifampicin resistance in smear negative PLHIV. It’s availability as an initial diagnostic test in PLHIV could significantly reduce the delay in initiation of treatment and prevent the transmission of the disease.

Mycobacterium tuberculosisDNA Detection and Molecular Drug Susceptibility Test in AFB-stained Sputum Slides

Tuberculosis (TB) remains an unsolved community health problem since identification of its causing microorganism called Mycobacterium tuberculosis (MTB) by Robert Koch in 1882. Annually, eight million TB cases are newly reported and 2~3 million patients die from TB. Pulmonary TB is highly infectious and untreated pulmonary TB patients are believed to infect >10 people in a year. The conventional methods for diagnosis of TB are chest X-ray and isolation of the causing microorganisms from patient specimens. Screening of TB is conducted with smeared sputum in slides, and TB is confirmed by identification of MTB in cultured specimens. One of the fatal pitfalls of screening detection for smeared sputum is that it is impossible to distinguish MTB and other acid-fast bacilli (AFB) because they are stained equally with Ziehl-Neelsen (ZN) stain. Culture of MTB is the most reliable method for diagnosis of TB but it takes 4~8 weeks. In this report, we suggest a fast and highly-reliable MTB detection method that distinguishes AFB in sputum samples. Purified DNA from the AFB stained slide samples offered by The Korean Institute of Tuberculosis were used to detect infected MTB in patients. PCR, real-time PCR and reverse blot hybridization assay (REBA) methods were applied to purified DNA. Conclusively, the real-time PCR method was confirmed to produce high sensitivity and we were able to further detect drug-resistant MTB with REBA.

Incidence of tuberculosis is high in chronic kidney disease patients in South East England and drug resistance common

The risk of tuberculosis (TB) is significantly increased in chronic kidney disease (CKD). Data on TB in CKD in the UK are sparse; most information stems from countries with high background prevalence. The aim of this study was to estimate the incidence of TB in CKD patients in South East London and to describe the epidemiology, treatment, and outcome. CKD patients with TB between 1994 and 2010 were identified retrospectively. Data were collected on type of renal replacement therapy, the method of TB diagnosis, disease site, treatment regimens, and risk factors. Forty patients were identified of whom 67.5% had CKD stages IV–V. Sixty-five percent were from non-UK born ethnic minorities. Median time from diagnosis of CKD to TB development was 12 months (range 0–192 months). Cumulative incidence of TB was 1267/100,000 [95% confidence interval (CI): 630–1904; 85 × background UK rate] in hemodialysis patients; 398/100,000 (95% CI: 80–1160; 26 × background UK rate) in peritoneal dialysis; and 522/100,000 (CI: 137–909; 35 × background UK rate) in transplant recipients. Sixty-three percent of patients had pulmonary TB and 25% of patients with culture-positive TB had resistant isolates. Fifty percent of patients were immunosuppressed due to drugs, diabetes, and/or retroviral disease. Treatment regimens were according to recent national guidance in 73% of cases. Seventy-six percent of patients experienced side effects. Greater awareness of risk factors, drug resistance, treatment regimens, and potential side effects is needed.

Conventional versus molecular methods for diagnosis of tuberculosis in a tertiary care center: A study from Punjab

Background: A fast and accurate diagnosis is necessary to control and eliminate tuberculosis (TB). There have been various studies evaluating the efficacy of polymerase chain reaction (PCR) testing in clinical practice. Most of these studies have found PCR as a useful tool to diagnose TB and more so for the extra-pulmonary cases. Aims and Objectives: The aim of the study was to evaluate the results of TB by real-time PCR versus the conventional methods of diagnosis in a tertiary care center in Punjab. Materials and Methods: This study was done in a tertiary care center of Punjab to look for the results of clinical samples tested for TB using PCR, Ziehl–Neelsen staining and culture on Lowenstein–Jensen medium. 16S rRNA gene was used for Mycobacterium tuberculosis detection in PCR. This study included all samples tested for TB from July 2015 to October 2015. Results: A total of 214 samples were tested for TB using smear microscopy, culture and PCR (including 194 [90.6%] extra-pulmonary and 20 [9.3%] pulmonary samples). These included 76 cerebrospinal fluid, 30 pleural fluid, 42 tissues, 17 ascitic fluid, 13 urine, 15 bronchoalveolar lavage (BAL), 16 pus, and 5 sputum samples. Smear microscopy was positive in a total of 4 samples out of 214 (1.8%), which included 2 sputum, 1 tissue, and 1 ascitic fluid samples, while culture was positive for 6 samples (2.8%) which included 2 sputum, 1 pus, 1 BAL, 1 tissue, and 1 ascitic fluid sample. The TB PCR results were positive in a total of 71 (33.1%) samples out of 214. In addition, three samples also tested positive for Mycobacteria other than TB. Conclusion: PCR is a very rapid and accurate diagnostic tool for early detection of TB in particularly for extrapulmonary TB.

Enhancing tuberculosis diagnosis by polymerase chainreaction: an experience at a tertiary hospital

Introduction: Tuberculosis (TB) persists as a severe global public health issue. The aim of the present study was to evaluate the performance of an in-house TB PCR (polymerase chain reaction) in sputum. Methods: DNA from sputum specimens were submitted to a nested-PCR protocol for the IS6110 region detection. PCR results were compared to those of the traditional methods for TB diagnosis, i.e., acid-fast bacilli (AFB) smear microscopy and culture. We analyzed sputum samples obtained from 133 patients. Results: A total of 48 (36%) cultures yielded indeterminate results due to contamination. This high contamination rate may be explained by the fact that samples from fibrocystic patients were included in this study. Additionally, other five samples were positive for nontuberculous mycobacteria (NTM). Therefore, it was possible to compare 80 patients for M. tuberculosis detection. We found 14 positive samples: five presented positive results in the three methods (5/14; 35.7%), two were positive in culture and PCR (2/14; 14.3%), one was positive in AFB and PCR (1/14; 7.1%), five were positive only in PCR (5/14; 35.7%) and 1 was positive only in culture (1/14; 7.1%). Thus, positivity rates for each technique were: 7.5% for AFB (6/80), 10% for culture (8/80) and 16.25% for PCR (13/80). Among the 48 patients who had indeterminate results in sputum culture, two samples were positive in PCR. Conclusion: Considering the limitations of the traditional methods, the use of PCR as a molecular technique could be advantageous for TB diagnosis.

PECULIARITIES OF CHEMIORESISTANT TUBERCULOSIS SPREAD IN TERNOPIL REGION IN RECENT YEARS

&lt;p&gt;&lt;em&gt;The article presents the&lt;/em&gt;&lt;em&gt; results of the study of susceptibility of M. tuberculosis isolated from patients with pulmonary tuberculosis in 2007 to -2013 in the Ternopol region (Ukraine)&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;The positive tendency of increasing the rate&lt;/em&gt;&lt;em&gt; of susceptibility of M. tuberculosis anti-TB drugs in 2013 in comparison 2007 in patients with new tuberculosis and other cases of tuberculosis but not recidivation was marked in Ternopil region&lt;/em&gt;&lt;em&gt;.&lt;/em&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;&lt;p&gt;&lt;em&gt;I&lt;/em&gt;&lt;em&gt;n&lt;/em&gt;&lt;em&gt; patients with new tuberculosis the number of pathogens which were susceptible to anti-TB drugs of the first line I for this period increased on 12,6%, while in patients with re-treatment of pulmonary tuberculosis, except recidivation - increased in 1,7 times, and in patients&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;with&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;of&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;pulmonary&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;tuberculosis relapses this index fluctuated between &lt;/em&gt;&lt;em&gt;27,1-47,6&lt;/em&gt;&lt;em&gt;%. &lt;/em&gt;&lt;/p&gt;&lt;p&gt;&lt;em&gt;T&lt;/em&gt;&lt;em&gt;he&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;relative&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;amount&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;of&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;multiresistant&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;strains&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;during&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;this&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;period&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;has deeply increased&lt;/em&gt;&lt;em&gt;. Thus, &lt;/em&gt;&lt;em&gt;in&lt;/em&gt;&lt;em&gt; patients with new pulmonary tuberculosis twofold increase of the rate of multidrug-resistant strains in 2012 compared to 2010-2011 years was revealed. The same trend was observed in patients with tuberculosis recidivation. &lt;/em&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;&lt;p&gt;&lt;em&gt;The attention was paid to &lt;/em&gt;&lt;em&gt;the &lt;/em&gt;&lt;em&gt;priority of the introduction of modern&lt;/em&gt;&lt;em&gt; express methods of tuberculosis diagnosis and examination of susceptibility of its causative agents to antimycobacterial drugs. It will permit to correct antimycobacterial treatment in time, and reduce the number of relapses and appearance of chronic pulmonary tuberculosis in patients with multiresistant pathogens.&lt;/em&gt;&lt;em&gt;&lt;/em&gt;&lt;/p&gt;

Evaluation of rapid methods for diagnosis of tuberculosis in slaughtered free-range pigs

Free-range pigs can be infected by Mycobacterium tuberculosis complex (MTC) and may contribute to the spread of bovine tuberculosis (bTB). In the present study, the diagnostic values of bacteriological culture, a duplex real-time quantitative PCR and an antibody ELISA were evaluated in an abattoir study of submandibular lymph nodes and serum samples from 73 pigs with and without lesions consistent with bTB. The duplex qPCR was an accurate method for diagnosis of TB in pigs (specificity 100%; sensitivity 80%). Combining qPCR with histopathology improved sensitivity and had very good concordance (κ = 0.94) with the reference method. Serological results suggest that the antibody ELISA can be used for monitoring herds but not individuals.

Evaluation of the Xpert MTB/RIF assay for diagnosis of tuberculosis and rifampin resistance in county-level laboratories in Hunan province, China

Background The Xpert MTB/RIF showed high sensitivity and specificity in previous studies carried out in different epidemiological and geographical settings and patient populations in high-burden tuberculosis (TB) countries. However, there were little data obtained by validation or demonstration study of the assay in China. In this study, the performance of Xpert MTB/RIF was investigated in two county-level laboratories in Hunan Province, China. Methods Consecutive patients with suspected pulmonary tuberculosis (PTB) and suspicion for multidrug-resistant tuberculosis (MDR-TB) were enrolled. For each patient suspected to have PTB, three sputum specimens (one spot sputum, one night sputum, and one morning sputum) were collected and each sputum was tested with smear microscopy, Löwenstein-Jensen (LJ) culture, and Xpert MTB/RIF test. For comparison across subgroups and testing methods, 95% confidence intervals were calculated. All analyses were done with SPSS 16.0, and P &lt;0.05 was regarded as significant. Results For case detection, the sensitivity of Xpert MTB/RIF was 100% for smear- and culture-positive TB and 88.6% for smear-negative and culture-positive TB; the overall sensitivity was 94.5% for all culture-positive patients. The specificity was 99.8%. The sensitivity of Xpert MTB/RIF assay was 22.0% in clinical TB patients and the specificity reached 100.0% in the group of patients who are infected with nontuberculous mycobacteria. For the detection of rifampin resistance, the sensitivity of MTB/RIF RIF-resistance detection was 92.9%, and the specificity was 98.7%. Of the 26 Xpert MTB/RIFpositive and RIF-resistant patients confirmed by LJ proportion tests, 20 (76.9%) patients were infected by MDR-TB. Conclusions The Xpert MTB/RIF assay is a highly sensitive and specific method for diagnosis of TB and RIF resistance, which will enable it to have the potential to be used in county-level laboratories and lead to the reduction of the infectious pool and improvements in TB control in China. Further evaluations in county-level laboratories for implementing the assay are still required.

The Clinical Utility of Polymerase Chain Reaction and Adenosine Deaminase (ADA), for the Diagnosis of Pleural Tuberculosis: Indian Scenario

Background and Objectives: In spite of higher incidence and prevalence of tuberculosis, the diagnosis of extra-pulmonary tuberculosis (EPTB) in various clinical specimens (such as pleural fluid, ascitic fluids, CSF, lymph node aspirate etc), remains true challenge. Current tools for the diagnosis of tuberculosis in various body fluids are suboptimal. Clinicians underestimate these diseases, and use of insensitive conventional analytical method has contributed to the difficulties in managing patient with extra pulmonary tuberculosis. It is important to develop rapid, sensitive and specific test for early diagnosis of extra pulmonary tuberculosis because of the lack of sensitivity & specificity of the conventional methods as AFB smear by ZN technique and culture on LJ media. Pleural tuberculosis (TB) diagnosis often requires invasive procedures such as pleural biopsy. The study was undertaken to evaluate the combined utility of polymerase chain reaction (PCR) for different gene targets (IS6110, MPB64 and protein antigen b; Pab ) especially in pleural fluid specimens with adenosine deaminase (ADA) levels in the diagnosis of pleurisy. Methods: Total 430 clinical specimens (412 extra-pulmonary and 18 pulmonary tuberculosis) were recruited from the outdoor and indoor Department of National Institute of Tuberculosis and Respiratory Diseases, New Delhi during the 2011-2013 periods. All specimens were further processed for AFB smear, culture on LJ media, ADA level and conventional PCR (IS6110 & MPB 64 and Pab gene targets). Results: The PCR positivity IS6110, MPB64 &Pab gene targets was found to be 90.3% (N=28/31) in smear negative & culture positive (as gold standard) extra pulmonary tuberculosis cases. However the total PCR positivity of Pab (43.9%; 181/412) gene target was found to be significantly low as compared to the IS6110 (65.3%; 269/412; X2=37.058; pc=0.000; Odds ratio 2.401; 95% CI=1.795-3.213) & MPB 64 (63.6%; 262/412; X2=31.245; pc=0.000; Odds ratio 2.229; 95% CI=1.669-2.978) gene targets in extra pulmonary tuberculosis cases. Further we have analyzed the combined utility of PCR with ADA levels among the body fluids (165 pleural fluid, 15 ascitic fluid, 1 lymph node and 1 cerebrospinal fluid; CSF). Our results indicated that the PCR alone can detect total 72.5% (132/182) TB cases, whereas ADA alone can detect 61.5% (112/182; considering cutoff value >40IU/L or confirmed cases of TB on clinic-radiological findings), M.tuberculosis in body fluids. Further data was compared in between single, two and three gene targets considering cut off value ADA >40IU/L levels in body fluids. Our observation showed that the positivity of tuberculosis cases were significantly higher through three gene targets (N=48/83; 57.8%; Mean of ADA >40IU/L =127.3) as compared to single gene target (N=10/83; 12.1%; Mean of ADA >40IU/L =68.2; X2=36.27; pc=0.000; Odds ratio 10.011; 95% CI=4.272-24.008) utilizing conventional PCR technology. No significant difference has been observed in other body fluids. The combined evaluation of both techniques (PCR and ADA) raised 14-15 % additional diagnosis of tuberculosis in body fluids (158/ 182; 86.8%; in pleural fluid= 147/165; 89.1%).Interpretation and Conclusion: Our results suggested that Protein antigen b (Pab) gene target showed less sensitivity as compared to IS6110 & MPB64. This study demonstrated the combined utility of both techniques (multigene target PCR with ADA level), enhanced the sensitivity of diagnosis of tuberculosis in body fluids. The study also confirmed the high diagnostic utility of PCR and ADA methods in diagnosis of tuberculosis in various paucibacillary body fluids in Indian scenario.

Tuberculosis risk and anti-tumour necrosis factor agents in rheumatoid arthritis: a critical appraisal of national registry data.

Tuberculosis (TB) remains a major global health problem. In patients with rheumatoid arthritis (RA), the risk of reactivation of latent TB infection (LTBI) is increased and treatment with tumour necrosis factor (TNF) antagonists further increases this risk. However, interpretation of results describing comparative TB risk during therapy with different TNF antagonists is difficult. This is not only a result of different patient ethnic groups and background TB rates, but also because of differing methods of data acquisition. This paper offers a critical appraisal of registry data pertaining to RA patients treated with different anti-TNF agents, focusing on methodological approaches that may limit the generalizability of findings or invalidate the direct comparison of TB risk between different national registries. Underlying factors that can make data interpretation challenging are discussed, including differences in methods for TB diagnosis or data collection and reporting, as well as background TB risk. The introduction of special monitoring systems, such as prospective multinational registries, to strengthen surveillance and better quantify the extent of under-reporting is required, especially in countries where the background TB risk is high.