Cartridge-based Nucleic Acid Amplification Test Research Articles

Intensified tuberculosis and HIV surveillance in a prison in Northeast India: Implementation research.

Structural and individual level factors in prisons create challenges towards detection and management of HIV/tuberculosis. WHO and India’s HIV/tuberculosis control programs recommend intensified case finding in prisons. Low HIV and tuberculosis detection rates suggest poor implementation of existing surveillance strategies within the prison healthcare system in Mizoram’s capital city of Aizawl. We explored the operational feasibility of implementing the intensified case finding strategy in Aizawl central prison. We implemented the intensified screening through entry screening of new inmates, mass screening of resident inmates and exit screening at release. We set up digital chest radiography, sputum smear microscopy and HIV testing facilities within the prison and referral to external facility for Cartridge Based Nucleic Acid Amplification Test (CBNAAT). We screened 738 inmates (Male: 626; Female: 112). Of 53% inmates having presumptive tuberculosis symptoms, 37% underwent sputum microscopy. We detected 14 new tuberculosis cases; overall tuberculosis positivity 1.9%. We tested 65% of 657 inmates for HIV, of which 41 new cases were detected; overall HIV positivity 16.5%. Three male inmates had HIV-tuberculosis co-infection. It is feasible to implement intensified case detection for tuberculosis/HIV in the prison with inter-departmental coordination, albeit with certain challenges.

Evaluation of cartridge-based nucleic acid amplification test for diagnosis of tuberculosis in children in various body fluids

Introduction: The paucibacillary nature presents a major challenge in the diagnosis of tuberculosis (TB) in children. The utilization of cartridge-based nucleic acid amplification test (CBNAAT) for the diagnosis of TB presents itself with added advantages such as detection to resistance to rifampicin and short turnaround time. Objectives: The aim of the study is to evaluate the diagnostic yield of CBNAAT in various body fluids and to compare with BACTEC-MGIT 960 and acid-fast bacilli (AFB) microscopy in children with suspected TB and to see the prevalence of rifampicin resistance in the study population using CBNAAT. Materials and Methods: This cross-sectional study included participants <14 years with suspected TB. Gastric aspirate samples obtained from pulmonary TB cases and body fluid specimens obtained from extrapulmonary TB cases were processed for the detection of Mycobacterium tuberculosis (MTB) using CBNAAT, BACTEC-MGIT 960, and AFB microscopy. The results obtained using CBNAAT were compared to other laboratory tests using an appropriate statistical method. Results: Fifty patients diagnosed with TB (34 pulmonary, 10 pleural effusion, and 6 abdominal) were included in the study, and clinical fluid specimens obtained from study participants were processed for the detection of MTB. Out of 34 gastric aspirate samples, 28 (82%) were positive by CBNAAT which was statistically higher than BACTEC-MGIT 960 (P < 0.05). Among extrapulmonary TB cases, only 2 pleural fluid specimens were positive by CBNAAT, whereas BACTEC-MGIT 960 and AFB microscopy could not detect MTB. Out of 34, 4 (11.76%) patients with newly diagnosed pulmonary TB were found to be rifampicin resistant using CBNAAT. Conclusions: CBNAAT showed promising results as a diagnostic tool in detecting MTB and rifampicin resistance in pulmonary TB using gastric aspirate. It, however, did not show good results in children with extrapulmonary TB in the clinical fluid specimen. The present study also showed the presence of high rifampicin resistance in treatment naïve pulmonary TB patients.

Active detection of tuberculosis: tackling the problem head on in the remote area of Andaman and Nicobar Islands

Background: Community based active case finding for tuberculosis (TB) is an essential step in the fight forward for eliminating TB. One of the steps in targeting TB intervention is early diagnosis and treatment of patients by reducing the reservoir of infection in the community. Active case finding (ACF) targeting the entire population by house to house survey was done in Nicobar district of these islands.Methods: A community-based, cross-sectional, descriptive study was conducted with the trained mobile teams from 17.07.2017 to 31.07.2017 in the Nicobar District. The algorithm of the case detection included screening patients by symptoms, then by sputum microscopy for confirmation. X-ray was done in patients who were symptomatic but sputum negative. If both smear and chest X-ray results were negative but still symptomatic, then cartridge-based nucleic acid amplification test (CBNAAT) was done.Results: A total population of 18526 was mapped of which 14784 (79.8) could be screened. A total of 209 people were identified by the mobile teams with symptoms who were examined by sputum microscopy. Among them 7 cases were identified to be sputum smear positive, 2 X-ray positive and 2 were diagnosed by CBNAAT.Conclusions: This study shows that the active case finding method is feasible and acceptable by the community. The results obtained are encouraging for the implementation of ACF through mobile team activity in all these islands in order to meet the target of WHO’s End TB Strategy.

Cartridge-based nucleic acid amplification test: a novel rapid diagnostic tool to study the burden of tuberculosis from a tertiary care hospital.

Despite efforts to limit the morbidity and mortality from tuberculosis (TB), it continues to be an important cause of death. There is an urgent need for a diagnostic test that accurately and quickly diagnoses TB, especially if it is also a near-point-of-care test. The GeneXpert polymerase chain reaction test (known in India as CBNAAT [cartridge-based nucleic acid amplification test] and is capable of diagnosing TB and rifampicin resistance within 2 h) is a promising tool. The duration of our study was two years and was carried out in the DOTS centre of a tertiary care hospital in India. A total of 5449 samples were processed using CBNAAT. Of the total samples tested, 2068 were extra-pulmonary. The following information was collected: number of extra-pulmonary samples processed; number of Mycobacterium tuberculosis (M. tuberculosis)-positive samples; patterns of rifampicin sensitivity; number of people living with HIV (PLHIV); and number of children. Of the samples, 62.1% were from suspected pulmonary TB patients. Out of the total samples tested using CBNAAT, 21.8% were positive for M. tuberculosis. Rifampicin resistance was seen in 9.2%, 8.5% and 10.3% of the total, pulmonary and extra-pulmonary samples, respectively, in M. tuberculosis-positive samples. Overall, 36.9% samples were from the paediatric population and 5.7% belonged to PLHIV. Rifampicin resistance was seen in 8.8% and 8.3% of the M. tuberculosis-positive paediatric and PLHIV samples, respectively.

Musculoskeletal tuberculosis: A diagnostic approach

Musculoskeletal tuberculosis constitutes 3 percent of extra pulmonary secondary tuberculosis predominantly involving the spine. The variations in its presentation and unclear symptoms make diagnosis difficult in early period. The normal lab values like ESR, TLC, DLC and no clear history of previous pulmonary infection makes the picture unclear and delays the diagnosis. Present work is the overview of the presentation of various musculoskeletal presentations, efficacy of BCG vaccination, time delay in diagnosis, laboratory parameters, x rays and other radiological changes etc. The reliability of the various lab procedures like AFB stain, histopathology, tuberculosis bacteria culture and cartridge-based nucleic acid amplification test (CBNAAT) has also been overviewed.

Study on cartridge based nucleic acid amplification test in children with Neurotuberculosis at RNT Medical College, Udaipur, Rajasthan, India

Background: The aim was to determine utility of Cartridge based nucleic acid amplification test (CBNAAT) in diagnosis of mycobacterium tuberculosis in children with neurotuberculosis diagnosed on the basis of clinical evaluation, CSF findings and neuroimaging.Methods: A prospective randomized controlled trial was conducted in Pediatric Department of RNT Medical College, Udaipur, Rajasthan, India from July 2017 to June 2018. Total 110 children of age group of 6 months to 18 years with the diagnosis of tubercular meningoencephalitis (TBME) on the basis of clinical evaluation, CSF examination and neuroimaging were included in the study.Results: A total 110 children were enrolled. Maximum number of cases admitted with TBME were among 1-5 years of age group (60.91%). CSF and gastric aspirate were examined by CBNAAT for MTB. 5 (4.55%) children had CBNAAT positivity in CSF. Gastric aspirate was positive among 16 (14.55%) children. None of the patient had CBNAAT positive result both in CSF and gastric aspirate.Conclusions: TBME is a major health problem in children below 5 years. Gene Xpert assay has the potential to significantly improve and escalate the diagnosis of smear-negative body fluid specimens. CBNAAT for mycobacterium tuberculosis was positive in 5 (4.55%) children from CSF and 16 (14.55%) from gastric aspirate. Negative CBNAAT should not prevent any patient with suspected features of TBME from starting anti tubercular treatment (ATT) as sensitivity of this test remains low. Final judgement to start ATT should be based on clinical, biochemical and radiological profile especially in CNS tuberculosis.

Pediatric TB Management under RNTCP: What and Why?

Childhood tuberculosis does not get the attention it deserves, both in the general child health services and the TB specific services. The difficulty in identification of the organism due to lack of proper sample as well as lower sensitivity of the smear, made it harder to detect cases with ease in the community. Newer diagnostic methods like cartridge based nucleic acid amplification tests (CBNAAT) and line probe assays (LPA) have the capacity to rapidly identify Mycobacterium tuberculosis with an improved sensitivity over the smear testing and have been employed under Revised National Tuberculosis Control Programme (RNTCP) across the country. As the symptoms suggestive of TB are very common and overlapping, the final yield of TB testing is better if the microbiological confirmation is done on good quality specimen from cases suspected of TB based on clinical and radiological abnormalities. Newer tests also provide simultaneous detection of much critical Rifampicin resistance. A Rifampicin resistantcase is not only unlikely to respond to first-line standard therapy but such a treatment can result in further amplification of resistance to other companion drugs. Prevention of spread of the drug resistant disease thus requires that the treatment is guided byuniversal drug sensitivity testing (U-DST) of all TB cases. Furthermore, several changes have come up in the treatment of TB and are discussed.The dosages of anti TB drugs have been revised upwardly for optimal drug levels and now the fixed drug combinations are used under RNTCP. With the awareness about high initial Isoniazid (INH) resistance and its contribution to failure of retreatment regime, a companion third drug (Ethambutol) has been added to the continuation phase of the first-line therapy. The standard retreatment regime, better known as category II therapy, has been replaced by specific therapy as per the resistance pattern detected. The TB control activities have thus evolved a lot and the present article discusses the evolution and the current status of diagnostics and therapy of TB in children.

Role of cartridge -based nucleic acid amplification test (CBNAAT) for early diagnosis of pulmonary tuberculosis in HIV

Background: Pulmonary Tuberculosis (PTB) is the commonest opportunistic infection and leading cause of death among people living with HIV (PLHIV). The role of cartridge based nucleic acid amplification test (CBNAAT) has potential to diagnose PTB and rifampicin resistance within two hours in PLHIV is promising. Methodology: 100 PLHIV patients with age of >18years having signs and symptoms greater than or equal to two weeks of duration and / or Chest X-ray findings suggestive of pulmonary tuberculosis who are attending to the department of Pulmonary Medicine, Guntur Medical College, Guntur from November 2016 to October 2017 are included in the study. Sputum samples sent for CBNAAT, AFB stain. Positive samples of CBNAAT and AFB stain are sent for conventional culture. Results: Out of 100 sputum samples, 45 were positive in CBNAAT, and 16 were AFB smear positive. All these 16 smear positive samples have 100% sensitivity in CBNAAT. These positive samples (45) were sent for culture. In culture out of 16 smear positive samples 15 are culture positive 1 is culture negative, which is false positive in CBNAAT also. In culture out of 45 CB-NAAT positive samples 29 culture positive, 16 culture negative. Sensitivity, specificity, PPV, NPV of smear in sputum samples are 46.88%, 98.5%, 93.75%, 79.76%, while that of CB-NAAT are 90.6%, 76.47%, 64. 44%, 94.55% respectively. Primary rifampicin resistance was detected in 1 case (2.22%) in CBNAAT and culture. Conclusions: CBNAAT is a rapid, reliable tool with least bio-safety concern and requires minimally trained staff, is best alternative to conventional methods of tubercular diagnosis and detects rifampicin resistance simultaneously within 2 hours. Keywords: CBNAAT; Sputum; TB.

Prospective study to find out the role of cerebrospinal fluid examination by cartridge-based nucleic acid amplification test and culture and sensitivity as a diagnostic method in childhood central nervous system tuberculosis

Introduction: Central nervous system (CNS) tuberculosis (TB), particularly tuberculous meningitis, is the severest form of Mycobacterium tuberculosis (MTB) infection causing severe neurological defects or even death. The recent introduction of cartridge-based nucleic acid amplification test (CBNAAT) has significantly transformed the diagnostics of TB in adults, but its application for the diagnosis of pediatric TB is under evaluation. Objective: This study was conducted by for cerebrospinal fluid (CSF) examination in the detection of MTB by the culture and sensitivity and CBNAAT in the diagnosis of childhood CNS TB. Methods: A prospective hospital-based study was conducted from July 2017 to June 2018 in the pediatric department of a tertiary care unit. A total of 65 randomly selected patients, suspected of CNS TB, were included in this study. CSF was tested for CBNAAT and culture and sensitivity other routine investigations such as specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for both CBNAAT and culture and sensitivity. Mantoux test was also performed, and the statistical analysis was performed using Chi-square test. p=0.05 was considered to be statistically significant. Results: Culture positive TB was found in 26 out of the 65 children. The sensitivity, specificity, PPV, and NPV for CBNAAT and culture and sensitivity were 65.71%, 90.00%, 88.46%, and 69.23%, respectively. CBNAAT was detected to be more in 12 TB cases and was more sensitive than culture and sensitivity. Positive history of contact (p=0.04), reactive Mantoux test (p<0.005), presence of Bacillus Calmette Guerin (BCG) scar (p=0.02), and low socioeconomic status were independently associated with a positive CBNAAT result. Conclusion: Analysis of CSF sample with CBNAAT is a sensitive and specific method for rapid diagnosis of CNS TB in children. Compared to culture and sensitivity, CBNAAT offers better sensitivity and its scale-up will improve access to CNS TB diagnostics in children. Although a negative CBNAAT does not rule out TB.

A prospective study of fistula in ano with reference to clinicopathology, imaging and management

Background: The aim was to study and review clinical presentation, pathological aspects & prevalent modalities of investigation and treatment for fistula in ano.Methods: A prospective study of 90 patients of fistula in ano admitted from March 2015 to December 2016 was done. Fistulography was done as a preliminary investigation in 72 cases and MR Fistulography was done for complex and recurrent fistula (16 cases). Patients were operated and histopathology of fistula tract was done. In patients with clinical suspicion of tuberculosis smear examination of pus with ziehl neelsen staining for acid fast bacilli (AFB) and Cartridge Based Nucleic Acid Amplification Test (CBNAAT) on pus/slide was used to find out tuberculosis in patients of anal fistula. The clinical presentation, operation performed, pathological findings were recorded & a descriptive analysis was done.Results: A prospective study of 90 patients of fistula in ano admitted from March 2015 to December 2016 was done. Fistulography was done as a preliminary investigation in 72 cases and MR Fistulography was done for complex and recurrent fistula (16 cases). Patients were operated and histopathology of fistula tract was done. In patients with clinical suspicion of tuberculosis smear examination of pus with ziehl neelsen staining for acid fast bacilli (AFB) and Cartridge Based Nucleic Acid Amplification Test (CBNAAT) on pus/slide was used to find out tuberculosis in patients of anal fistula. The clinical presentation, operation performed, pathological findings were recorded & a descriptive analysis was done.Conclusions: With careful clinical evaluation, appropriate imaging studies and conventional surgical techniques anal fistula can be treated effectively with less morbidity, incontinence and recurrence.

Isoniazid mono-resistant tuberculosis: Time to take it seriously

Background/AimsIn drug resistant tuberculosis (DRTB) suspects, rifampicin resistance has always been prioritized, hence Cartridge Based Nucleic Acid Amplification Test (CBNAAT) is recommended under Revised National Tuberculosis Control Programme (RNTCP), India. However, since it doesn't detect isoniazid resistance, rifampicin sensitive patients with unknown isoniazid status may be erroneously treated as drug sensitive TB, leading to poor treatment outcomes and emergence of multidrug resistant (MDR) TB. Hence isoniazid mono-resistance should be specifically looked for and treated as per recommendations.The objective of the present study, almost the first of its kind in India, was to evaluate the burden of isoniazid mono-resistance amongst patients diagnosed with DRTB and to study the association of different patient and disease related factors with treatment outcomes under the treatment regimen specific for isoniazid mono-resistance, started from January 1, 2017 in our state, under RNTCP. MethodsIt was a retrospective study which scrutinized medical records of 52 isoniazid mono-resistant TB patients started on treatment under RNTCP between January 1 to December 31, 2017. Necessary information on possible patient and disease related predicting factors like gender, age, type of mutation (katG/inhA), weight band (26–45 kg/46-70 kg), total serum protein/albumin levels, previous history of anti-tubercular treatment (ATT), history of smoking, HIV status, presence of diabetes mellitus (DM), presence of anemia, occurrence of adverse drug reactions (ADR) during treatment and duration of intensive phase (IP), was retrieved. These factors were analyzed for their possible association with treatment outcomes. ResultsOut of 103 DRTB patients enrolled, 50.5% (52/103) patients were diagnosed with isoniazid mono-resistance. 50/103 were MDR-TB and 1/103 were extensively-drug resistant TB (XDR-TB). Further analysis of these 52 isoniazid mono-resistant patients revealed:35 (67.3%) were males and 17 (32.7%) females. 27 (51.9%) patients were <30 years, 25 (48.1%) being ≥30 years of age. All patients were negative for HIV. 34/52 (65.4%) patients were declared cured, 15/52 were lost to follow up (LTFU) and 3/52 died (1 male, 2 females). Excluding these 3 patients who died, cure rates were significantly better in females (14/15 = 93.3%), with only 1/15 LTFU, than males (20/34 = 58.8% cure, 14/34 = 41.2% LTFU), (p = 0.019). Patients who were <30 years of age had significantly better cure rates (21/25 = 84%) with lesser LTFU's (4/25 = 16%), than those ≥30years of age (13/24 = 54.2% cure, 11/24 = 45.8% LTFU), (p = 0.032). Review of previous history of ATT revealed that 33 patients had primary isoniazid mono-resistance, 4 patients had previous history of being LTFU, 9 had recurrent TB and 3 were labeled as failure. Cure rates were significantly better in primary isoniazid mono-resistant patients (26/33 = 78.8%), than those with previous history of being LTFU(0/4), (p = 0.04).Type of mutation, weight band, total serum protein/albumin, history of smoking, presence of DM, presence of anemia, occurrence of ADR and duration of IP did not affect treatment outcomes. ConclusionIsoniazid mono-resistance formed a major chunk of DRTB, with majority of the patients detected with primary mono-resistance. Strategically framed treatment regimens for isoniazid mono-resistance under RNTCP in India are effective in a wide range of population. Still, there are high chances of LTFU/default, which needs to be addressed on priority. Male gender, age ≥30 years and being LTFU in the past are associated with poorer cure rates, hence should be paid special attention.

Role of fine needle aspiration cytology as a diagnostic tool in lymphadenopathy with utility of CBNAAT in tuberculous lymphadenopathy

Introduction: Lymphadenopathy is a common, nonspecific clinical sign. Fine Needle Aspiration Cytology (FNAC) is the first line of investigation in the evaluation of lymphadenopathy. FNAC material can be used for cytological evaluation and other ancillary tests in Tuberculous Lymphadenopathy. Aims and Objectives To evaluate the role of FNAC as a diagnostic tool in lymphadenopathy. To assess the role of Cartridge based nucleic acid amplification test (CBNAAT) in suspected cases of tuberculous lymphadenopathy. Materials and methods: The study conducted at department of Pathology in MVJMC &RH, Hoskote, Bangalore from January 2017 to June 2018 A total of 104 cases of lymphadenopathy were subjected to FNAC. In each case at least 3 smears for H & E, Giemsa stain and Special stain like AFB done for tuberculous lymphadenopathy. FNAC material sent for CBNAAT in suspected cases of Tuberculosis . Results: The age ranged from 1-90years, Male:Female of ratio1.26 :1. Most common site was cervical and cytological pattern was granulomatous -41(39.4%) followed by reactive -38(36.5%).Majority of them presented with solitary node (77%) and followed by bilateral/multiple (23%). One case of reactive (11%), two cases of suppurative (50%) and ten cases of granulomatous (37%) were found to be positive for Tuberculosis by CBNAAT. Conclusion: FNAC is simple, cost effective diagnostic tool with high degree of accuracy.FNAC coupled with AFB staining is the first line of investigation for Tuberculous lymphadenopathy. According to New Revised National TB Control Programme (RNTCP) guidelines CBNAAT sputum is a must for paediatric cases. The present study highlights the utility of CBNAAT from FNAC material as one of the rapid and adjuvant diagnostic tool in tuberculous lymphadenopathy. Keywords: FNAC, Tuberculous lymphadenopathy, CBNAAT.

Comparison of Ziehl-Neelsen's stain, fluorescent stain with CBNAAT of sputum for the diagnosis of pulmonary tuberculosis

Introduction: Pulmonary tuberculosis remains one of the most dangerous communicable diseases. More than two billion people are estimated to be infected with Mycobacterium tuberculosis. In 2017, approximately 10 million individuals became ill with tuberculosis,among them 2.79 million individuals were active cases, 1.6 million died among which 0.3 million died with coexistent HIV infection. Prompt diagnosis of active tuberculosis facilitates timely therapeutic intervention and minimize the community transmission. As tuberculosis is a global problem, for eradication of the disease, early diagnosis, timely identification and improved detection is essential. The diagnosis of tuberculosis is challenging in cases of insufficient sputum and paucity of bacilli. With this background, this study was planned to compare Ziehl-Neelsen's stain, Fluorescent stain and CBNAAT (Cartridge based nucleic acid amplification test) as per RNTCP guidelines.Material and Methods: A prospective interventional study was carried out using 188 sputum samples of suspected pulmonary tuberculosis. All 188 samples were subjected to three methods Ziehl-Neelsen's stain, fluorescent stain and CBNAAT. They were compared for sensitivity and specificity in terms of qualitative results. The data recorded was then analyzed statistically.Results: In our study out of 188 cases 124 were males, 64 were females. Out of 188 samples, the smear positivity rate of ZN stain was 33.5%, fluorescent stain was 40.9%, and the positivity rate of CBNAAT was 51.1%.Conclusion: CBNAAT is more sensitive and specific in detection of pulmonary TB. An additional feature of rifampicin resistance can also be detected by CBNAAT.

Early diagnosis of smear-negative childhood pulmonary tuberculosis and its substantial yield in gastric lavage/aspirates through cartridge-based nucleic acid amplification test (Xpert Mycobacterium tuberculosis/rifampicin assay)

Introduction: Tuberculosis (TB) still remains the major public health threat in India. Early diagnosis is a priority as any delay may complicate the prognosis further leading to the failure of an effective control. India accounts for 6% incidence of pediatric TB cases in a population that has 40% as estimated latent TB cases. Gastric Lavage /aspirates were taken under study for pediatric patients as key population. Collection of sputum samples from the pediatric patients has been very difficult. The most common implementation of cartridge-based nucleic acid amplification tests (CBNAATs) in diagnosis of pediatric TB has augmented the detection rates. As a mandate for universal drug sensitivity, testing of smear-negative pediatric samples is set as a priority. The program included the smear-negative pulmonary samples contributing to high yield after sputum includes induced sputum, bronchoalveolar lavage, gastric aspirate, and gastric lavage. The study involves an analysis probing into the percentage contribution of these samples and the substantial yields of gastric lavage among these samples. Methods: Pulmonary pediatric samples were tested on CBNAAT by Xpert Mycobacterium tuberculosis/rifampicin (RIF) (Cepheid) based on the manufacturer's instruction. All necessary aseptic measures were taken. The data were captured in the Xpert software automatically during the tests and exported to the Microsoft Excel sheets for further analysis. A defined study design against each and every objective was set up. Results: From earlier studies, it was found that a point prevalence of 6%–7% of pediatric TB exists among the tested specimens every quarter. The periodic prevalence was found to be 5%, and the incidence rates ranged from 4.5% to 5%. RIF resistance detection showing a seasonal variation ranged from 13% to 15% among the CBNAAT-positive cases. Conclusions: The study concluded that more skilled collection centers for biological specimens are required to address the undetected pulmonary TB cases among the pediatric age group, especially below 6 months of age. About 5% prevalence and around 4.9% incidence is an alarming situation in the TB control scenario of West Bengal. Gastric lavage showed a major detection in children aged below 6 months of whom collecting sputum samples were difficult. This prompted suboptimal detection levels due to the dearth of sample collection modalities at the peripheries.

Challenges in the diagnosis of drug-resistant tuberculosis by GeneXpert MTB/Rif in Nepal

Introduction: GeneXpert MTB/Rif assay is an automated, cartridge-based nucleic acid amplification test that can accurately detect both tuberculosis and Rifampicin resistance. Since its introduction, there has been a steady uptake of this technology by the National Tuberculosis Program of Nepal. Nevertheless, a large number of drug-resistant TB cases remains undiagnosed. This study aims to examine the challenges in diagnosis of drug-resistant tuberculosis by the GeneXpert MTB/Rif assay in Nepal and explore the possible solutions.&#x0D; Methods: This was a cross-sectional study consisting of two parts – a quantitative part assessing the individual details and a qualitative part assessing the challenges on the diagnosis of drug-resistant TB by GeneXpert MTB/Rif assay. Data were collected from the GeneXpert operators, clinicians and program managers from 16 centers across the country and analyzed by IBM SPSS for Windows v23 and QDA Miner 4 Lite. Descriptive statistics were used to summarize the sociodemographic and other characteristics of the study participants using mean, standard deviation and proportions as appropriate.&#x0D; Results: A total of 48 technical manpower participated in the study. The mean age was 39.95 years and a majority of them (77.3%) were male. The major challenges identified were inadequate training, frequent power failure, difficulty in maintaining appropriate steady temperature, module failure which is often not replaced in time, issues with calibration and timely availability of cartridges as well as appropriate ways to store the new cartridges and safe disposal of the used cartridges.&#x0D; Conclusion: A number of challenges limit the optimal utilization of GeneXpert MTB/Rif assay warranting action.

Role of GeneXpert in Rapid Molecular Detection of Extrapulmonary Tuberculosis in Tertiary Care Hospital

Introduction: Tuberculosis, the most common infectious disease with prevalence of 9.6 million globally. Most prevalent (23%) in India. Extrapulmonary tuberculosis (EPTB) accounts for 20% of total burden of tuberculosis. Rapid detection of Mycobacterium Tuberculosis (MTB) is essential for effective disease management. CBNAAT (Cartridge Based NucleicAcid Amplification Test) or GeneXpert MTB/RIF assay - novel diagnostic tool to detect MTB and RIF resistance simultaneously. WHO recommends its utility for non-respiratory samples also. Burden of EPTB and drug resistance vary from place to place. Objective: Study was conducted to gather information about burden of disease in our locality and to assesutility of CBNAAT in detecting MTB and rifampicin resistance in suspected EPTB cases. Methods: Retrospective analysis of 281 samples from suspected cases collected in falcon tubes and processed using CBNAAT. Result: Total of 281 extrapulmonary samples received, 67(23.8%) were positive and 214(76.1%) were negative for MTB. Of 67 positives, RIF resistance detected in 1(1.49%) case. Maximum number of MTB detected in the age group 21-30 years (n=23, 34.3%). Among 165 males and 116 females, MTB detected in 44(26.6%) and 23(19.8%) respectively. Out of 281 patients, 24(8.54%) were HIV positive. Of these 24, only 8(33.3%) found positive for MTB. Among 257 non-HIV patients, MTB detected in 59(22.9%). Among different samples received, maximum number were Pleural fluid n=115(40.9%) and Maximum MTB positives found in FNAC (of lymphnodes) samples [n=35(52.2%)]. : CBNAAT is a rapid test to detect MTB and rifampicin resistance simultaneously in EPTB and it reduced the treatment abuse in suspected cases.

Concomitant methicillin-resistant Staphylococcus aureus infection in tubercular sacroiliitis masquerading as anti-tubercular drug resistance: Role for molecular diagnosis

A 23-year-old female on anti-tubercular therapy for tuberculous sacroiliitis presented with right sided gluteal and thigh abscess. Suspecting treatment failure, surgical evacuation of purulent material was done. The bacteriological isolation showed positivity for methicillin-resistant Staphylococcus aureus. Although the microbiological and histopathology examination of the specimen were negative for tubercular isolates, the cartridge based –nucleic acid amplification tests revealed positive genes for Mycobacterium tuberculosis and additional primers showed sensitivity for rifampicin and isoniazid. She was adequately treated with vancomycin for six weeks and anti-tubercular drugs for eight months and followed till the bony ankyloses at 18 months. This is a rare case based scenario wherein concomitant staphylococcal infection in tubercular sacroiliitis masqueraded as anti-tubercular drug resistance. The cartridge-based nucleic acid amplification test for tuberculosis is a rapid and sensitive modality in identifying mycobacteria even mixed infections and also determine drug resistance. There are fewer consensuses in the literature regarding the drugs and duration of anti-tubercular regime for tuberculous sacroiliitis with most regimes using four drugs between six to eighteen months.

Prospective study to find out the role of gastric aspirate examination by Ziehl-Neelsen staining (ZN staining) and cartridge based nucleic acid amplification test (CB-NAAT) as a diagnostic method in childhood tuberculosis

Background: Tuberculosis in children has been relatively neglected mainly because clinical diagnosis has low specificity, radiological interpretation is subject to inter-observer variability and the tuberculin skin test is a marker of exposure, not disease. The recent introduction of Cartridge based nucleic acid amplification test has significantly transformed the diagnostics of tuberculosis in adults but its application for Paediatric Tuberculosis is under evaluation. Therefore, authors conducted a study on role of gastric aspirate examination by ZN stain and Cartridge based nucleic acid amplification test in the diagnosis of childhood Tuberculosis.Methods: Authors did a prospective hospital-based study from Nov 2016 to Nov 2017 consisting of 100 randomly selected patients suspected of tuberculosis who had their gastric aspirate tested for CBNAAT and ZN stain for acid fast bacilli (AFB) along with Mantoux test and other routine investigations. Chi square test was used.Results: Culture positive tuberculosis was found in 21 out of 100 children. The sensitivity, specificity, positive predictive value and negative predictive value for CBNAAT were 76.1%, 98.7%, 94.1% and 93.9% and for ZN stain were 47.6%, 98.7%, 90.9% and 87.6% respectively. Positive history of contact (p value 0.0217), reactive Mantoux test (p value &lt; 0.001) and low socioeconomic status were independently associated with a positive CBNAAT result.Conclusions: Analysis of gastric aspirate samples with CBNAAT is a sensitive and specific method for rapid diagnosis of pulmonary tuberculosis in children who cannot produce sputum. Compared with microscopy, CBNAAT offers better sensitivity and its scale up will improve access to tuberculosis diagnostics in children.

Role of Cartridge based nucleic acid amplification test (CBNAAT) in new sputum negative pulmonary tuberculosis

Role of Cartridge based nucleic acid amplification test (CBNAAT) in new sputum negative pulmonary tuberculosis

Clinical Spectrum of Pediatric Tuberculosis: A Microbiological Correlation from a Tertiary Care Center.

The paucibacillary nature of pediatric tuberculosis (TB) makes diagnosis difficult. The aim of the study was to correlate the clinical spectrum of pediatric TB with microbiological diagnosis. Specimens from clinically suspected pediatric TB cases were subjected to Ziehl-Neelsen staining, culture on Lowenstein-Jensen medium and cartridge-based nucleic acid amplification test (CB-NAAT) for TB. Pulmonary TB was the predominant form affecting 36 of 62 (58%) patients. Tubercular meningitis was the commonest form of extrapulmonary type and affected 13 of 26 (50%) children. Microbiological diagnosis by any of the above methods could be established in 35 (56.45%) cases. While 33 of 36 (92%) patients diagnosed with pulmonary TB had radiological findings, of which only 25 (76%) could be microbiologically confirmed, only 24 of 31 (77%) patients with extrapulmonary symptoms had radiological evidence and microbiological confirmation could be achieved in 4 (17%) of these. An integrated approach of diagnosis, including clinical-radiological, microbiological and immunological evidence should be stressed on.