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Search Results: 1 - 10 of 1136 matches for " Madhukar Pai "
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Serial Testing for Tuberculosis: Can We Make Sense of T Cell Assay Conversions and Reversions?
Madhukar Pai ,Richard O'Brien
PLOS Medicine , 2007, DOI: 10.1371/journal.pmed.0040208
Evidence-Based Tuberculosis Diagnosis
Madhukar Pai ,Andrew Ramsay,Richard O'Brien
PLOS Medicine , 2008, DOI: 10.1371/journal.pmed.0050156
Achieving Systemic and Scalable Private Sector Engagement in Tuberculosis Care and Prevention in Asia
William A. Wells?,Mukund Uplekar?,Madhukar Pai
PLOS Medicine , 2015, DOI: 10.1371/journal.pmed.1001842
Tuberculosis among Health-Care Workers in Low- and Middle-Income Countries: A Systematic Review
Rajnish Joshi,Arthur L Reingold,Dick Menzies,Madhukar Pai
PLOS Medicine , 2006, DOI: 10.1371/journal.pmed.0030494
Abstract: Background The risk of transmission of Mycobacterium tuberculosis from patients to health-care workers (HCWs) is a neglected problem in many low- and middle-income countries (LMICs). Most health-care facilities in these countries lack resources to prevent nosocomial transmission of tuberculosis (TB). Methods and Findings We conducted a systematic review to summarize the evidence on the incidence and prevalence of latent TB infection (LTBI) and disease among HCWs in LMICs, and to evaluate the impact of various preventive strategies that have been attempted. To identify relevant studies, we searched electronic databases and journals, and contacted experts in the field. We identified 42 articles, consisting of 51 studies, and extracted data on incidence, prevalence, and risk factors for LTBI and disease among HCWs. The prevalence of LTBI among HCWs was, on average, 54% (range 33% to 79%). Estimates of the annual risk of LTBI ranged from 0.5% to 14.3%, and the annual incidence of TB disease in HCWs ranged from 69 to 5,780 per 100,000. The attributable risk for TB disease in HCWs, compared to the risk in the general population, ranged from 25 to 5,361 per 100,000 per year. A higher risk of acquiring TB disease was associated with certain work locations (inpatient TB facility, laboratory, internal medicine, and emergency facilities) and occupational categories (radiology technicians, patient attendants, nurses, ward attendants, paramedics, and clinical officers). Conclusions In summary, our review demonstrates that TB is a significant occupational problem among HCWs in LMICs. Available evidence reinforces the need to design and implement simple, effective, and affordable TB infection-control programs in health-care facilities in these countries.
Point-of-Care Urine Tests for Smoking Status and Isoniazid Treatment Monitoring in Adult Patients
Ioana Nicolau, Lulu Tian, Dick Menzies, Gaston Ostiguy, Madhukar Pai
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0045913
Abstract: Background Poor adherence to isoniazid (INH) preventive therapy (IPT) is an impediment to effective control of latent tuberculosis (TB) infection. TB patients who smoke are at higher risk of latent TB infection, active disease, and TB mortality, and may have lower adherence to their TB medications. The objective of our study was to validate IsoScreen and SmokeScreen (GFC Diagnostics, UK), two point-of-care tests for monitoring INH intake and determining smoking status. The tests could be used together in the same individual to help identify patients with a high-risk profile and provide a tailored treatment plan that includes medication management, adherence interventions, and smoking cessation programs. Methodology/Principal Findings 200 adult outpatients attending the TB and/or the smoking cessation clinic were recruited at the Montreal Chest Institute. Sensitivity and specificity were measured for each test against the corresponding composite reference standard. Test reliability was measured using kappa statistic for intra-rater and inter-rater agreement. Univariate and multivariate logistic regression models were used to explore possible covariates that might be related to false-positive and false-negative test results. IsoScreen had a sensitivity of 93.2% (95% confidence interval [CI] 80.3, 98.2) and specificity of 98.7% (94.8, 99.8). IsoScreen had intra-rater agreement (kappa) of 0.75 (0.48, 0.94) and inter-rater agreement of 0.61 (0.27, 0.90). SmokeScreen had a sensitivity of 69.2% (56.4, 79.8), specificity of 81.6% (73.0, 88.0), intra-rater agreement of 0.77 (0.56, 0.94), and inter-rater agreement of 0.66 (0.42, 0.88). False-positive SmokeScreen tests were strongly associated with INH treatment. Conclusions IsoScreen had high validity and reliability, whereas SmokeScreen had modest validity and reliability. SmokeScreen tests did not perform well in a population receiving INH due to the association between INH treatment and false-positive SmokeScreen test results. Development of the next generation SmokeScreen assay should account for this potential interference.
Comparison of LED and Conventional Fluorescence Microscopy for Detection of Acid Fast Bacilli in a Low-Incidence Setting
Jessica Minion,Madhukar Pai,Andrew Ramsay,Dick Menzies,Christina Greenaway
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0022495
Abstract: Light emitting diode fluorescence microscopes have many practical advantages over conventional mercury vapour fluorescence microscopes, which would make them the preferred choice for laboratories in both low- and high-resource settings, provided performance is equivalent.
Is Scale-Up Worth It? Challenges in Economic Analysis of Diagnostic Tests for Tuberculosis
David W. Dowdy ,Adithya Cattamanchi,Karen R. Steingart,Madhukar Pai
PLOS Medicine , 2011, DOI: 10.1371/journal.pmed.1001063
Serological Testing Versus Other Strategies for Diagnosis of Active Tuberculosis in India: A Cost-Effectiveness Analysis
David W. Dowdy,Karen R. Steingart,Madhukar Pai
PLOS Medicine , 2011, DOI: 10.1371/journal.pmed.1001074
Abstract: Background Undiagnosed and misdiagnosed tuberculosis (TB) drives the epidemic in India. Serological (antibody detection) TB tests are not recommended by any agency, but widely used in many countries, including the Indian private sector. The cost and impact of using serology compared with other diagnostic techniques is unknown. Methods and Findings Taking a patient cohort conservatively equal to the annual number of serological tests done in India (1.5 million adults suspected of having active TB), we used decision analysis to estimate costs and effectiveness of sputum smear microscopy (US$3.62 for two smears), microscopy plus automated liquid culture (mycobacterium growth indicator tube [MGIT], US$20/test), and serological testing (anda-tb ELISA, US$20/test). Data on test accuracy and costs were obtained from published literature. We adopted the perspective of the Indian TB control sector and an analysis frame of 1 year. Our primary outcome was the incremental cost per disability-adjusted life year (DALY) averted. We performed one-way sensitivity analysis on all model parameters, with multiway sensitivity analysis on variables to which the model was most sensitive. If used instead of sputum microscopy, serology generated an estimated 14,000 more TB diagnoses, but also 121,000 more false-positive diagnoses, 102,000 fewer DALYs averted, and 32,000 more secondary TB cases than microscopy, at approximately four times the incremental cost (US$47.5 million versus US$11.9 million). When added to high-quality sputum smears, MGIT culture was estimated to avert 130,000 incremental DALYs at an incremental cost of US$213 per DALY averted. Serology was dominated by (i.e., more costly and less effective than) MGIT culture and remained less economically favorable than sputum smear or TB culture in one-way and multiway sensitivity analyses. Conclusions In India, sputum smear microscopy remains the most cost-effective diagnostic test available for active TB; efforts to increase access to quality-assured microscopy should take priority. In areas where high-quality microscopy exists and resources are sufficient, MGIT culture is more cost-effective than serology as an additional diagnostic test for TB. These data informed a recently published World Health Organization policy statement against serological tests. Please see later in the article for the Editors' Summary
Research Questions and Priorities for Tuberculosis: A Survey of Published Systematic Reviews and Meta-Analyses
Ioana Nicolau, Daphne Ling, Lulu Tian, Christian Lienhardt, Madhukar Pai
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0042479
Abstract: Background Systematic reviews are increasingly informing policies in tuberculosis (TB) care and control. They may also be a source of questions for future research. As part of the process of developing the International Roadmap for TB Research, we did a systematic review of published systematic reviews on TB, to identify research priorities that are most frequently suggested in reviews. Methodology/Principal Findings We searched EMBASE, MEDLINE, Web of Science, and the Cochrane Library for systematic reviews and meta-analyses on any aspect of TB published between 2005 and 2010. One reviewer extracted data and a second reviewer independently extracted data from a random subset of included studies. In total, 137 systematic reviews, with 141 research questions, were included in this review. We used the UK Health Research Classification System (HRCS) to help us classify the research questions and priorities. The three most common research topics were in the area of detection, screening and diagnosis of TB (32.6%), development and evaluation of treatments and therapeutic interventions (23.4%), and TB aetiology and risk factors (19.9%). The research priorities determined were mainly focused on the discovery and evaluation of bacteriological TB tests and drug-resistant TB tests and immunological tests. Other important topics of future research were genetic susceptibility linked to TB and disease determinants attributed to HIV/TB. Evaluation of drug treatments for TB, drug-resistant TB and HIV/TB were also frequently proposed research topics. Conclusions Systematic reviews are a good source of key research priorities. Findings from our survey have informed the development of the International Roadmap for TB Research by the TB Research Movement.
A commercial line probe assay for the rapid detection of rifampicin resistance in Mycobacterium tuberculosis: a systematic review and meta-analysis
Maureen Morgan, Shriprakash Kalantri, Laura Flores, Madhukar Pai
BMC Infectious Diseases , 2005, DOI: 10.1186/1471-2334-5-62
Abstract: We did a systematic review and meta-analysis to evaluate the accuracy of LiPA for the detection of rifampicin-resistant tuberculosis among culture isolates and clinical specimens. We searched Medline, Embase, Web of Science, BIOSIS, and Google Scholar, and contacted authors, experts and the manufacturer. Fifteen studies met our inclusion criteria. Of these, 11 studies used culture isolates, one used clinical specimens, and three used both. We used a summary receiver operating characteristic (SROC) curve and Q* index to perform meta-analysis and summarize diagnostic accuracy.Twelve of 14 studies that applied LiPA to isolates had sensitivity greater than 95%, and 12 of 14 had specificity of 100%. The four studies that applied LiPA directly to clinical specimens had 100% specificity, and sensitivity that ranged between 80% and 100%. The SROC curve had an area of 0.99 and Q* of 0.97.LiPA is a highly sensitive and specific test for the detection of rifampicin resistance in culture isolates. The test appears to have relatively lower sensitivity when used directly on clinical specimens. More evidence is needed before LiPA can be used to detect MDR-TB among populations at risk in clinical practice.Tuberculosis (TB) continues to be a major public health problem, particularly in developing countries. The WHO estimates that one third of the world's population is infected with Mycobacterium tuberculosis, the causative agent of TB. There were an estimated 8.3 million new active cases and 1.8 million deaths from TB in the year 2000, making it the second greatest killer among infectious diseases worldwide [1].The prevalence of multidrug-resistant TB (MDR-TB), defined as resistance to at least rifampicin (RIF) and isoniazid (INH), is rising in a number of geographic regions. According to a recent WHO report [1], the median prevalence of MDR-TB is 1% (range 0%–14.1%) among new cases and 9.3% (range 0%–48%) among previously treated cases. Rapid identification is essential for effecti
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