Tuberculosis Diagnostics Research Articles

DNA Methylation Patterns of Interferon Gamma Gene Promoter and Serum Level in Pulmonary Tuberculosis: Their Role in Prognosis

Tuberculosis (TB) still remains an important medical problem due to high levels of morbidity and mortality worldwide. A series of innate immune mechanisms that create a cytokine network control the pathogenesis of tuberculosis and this response has the capacity to modify the host genomic DNA structure through epigenetic mechanisms such as DNA methylation which could constantly alter the local gene expression pattern that can modulate the metabolism of the tissues and the immune-response. Interferon-gamma (IFN-γ) is an important pro-inflammatory cytokine regulator of the innate immune response to TB. This study aims to determine DNA methylation patterns of INF-γ gene promoter and measure serum IFN- γ level in newly diagnosed TB patients, relapse TB patients, and healthy control, in order to study the possibility of using these as a biomarker for the prognosis of TB stages in patients. The current case-control study included 66 patients with TB and 33 healthy control subjects. DNA was extracted from peripheral blood(PB) of included subjects and modified using sodium bisulfate specific kit. DNA methylation patterns of IFN-γ gene promoter was determine by using methylation specific polymerase chain reaction(MS-PCR).Serum IFN-γ level was determined using enzyme linked immune-sorbent assay(ELISA). Results showed that percentages of DNA methylation patterns in normal controls, newly diagnostic TB patients and relapse TB patients were (63.3%, 18.2% and 21.2% respectively). Also, higher significant differences (P≤0.0001) of un-methylated IFN-γ gene promoter patterns in newly diagnostic TB patients than relapse TB patients comparison with healthy controls. The percentage of un-methylated DNA patterns in healthy controls, newly diagnostic TB patients and relapse TB patients were (9.9%, 39.4% and 51.5%, respectively). The mean of serum IFN-γ levels (pg/ml) for normal controls, newly diagnostic TB patients and relapse TB patients were (59.3± 13.8,75.8±24.3 and 69.6±18.7,respectively).In conclusion, there is a relative association between methylation of IFN-γ gene promoter and predisposing to TB progression.

Tuberculosis and other bacterial co-infection in Cambodia: a single center retrospective cross-sectional study

BackgroundCambodia, a lower middle-income country of about 16 million individuals in southeast Asia, endures a high burden of both tuberculosis and other lower respiratory infections. Differentiating tuberculosis from other causes of respiratory infection has important clinical implications yet may be challenging to accomplish in the absence of diagnostic microbiology facilities. Furthermore, co-infection of tuberculosis with other bacterial lower respiratory infections may occur. The objective of this study was to determine the prevalence and etiologies of tuberculosis and other bacterial co-infection and to analyze the clinical and radiographic characteristics of patients presenting with respiratory infection to a provincial referral hospital in Cambodia.MethodsWe performed a retrospective, cross-sectional analysis of laboratory and clinical data, on patients presenting with respiratory symptoms to a chest clinic of a 260-bed provincial referral hospital in Cambodia. We analyzed mycobacterial and bacterial sputum test results, and demographics, medical history and chest radiography.ResultsAmong 137 patients whose treating clinicians ordered sputum testing for tuberculosis and other bacteria, the median age was 52 years, 54% were male, 3% had HIV infection, and 26% were current smokers. Nearly all had chronic respiratory symptoms (> 96%) and abnormal chest radiographs (87%). Sputum testing was positive for tuberculosis in 40 patients (30%) and for bacteria in 60 patients (44%); 13 had tuberculosis and bacterial co-infection (9% overall; 33% of tuberculosis patients). Clinical characteristics were generally similar across pulmonary infection types, although co-infection was identified in 43% of patients with one or more cavitary lesions on chest radiography. Among those with bacterial growth on sputum culture, Gram negative bacilli (Klebsiella and Pseudomonas spp.) were the most commonly isolated.ConclusionsAmong patients with symptoms of respiratory infections whose treating clinicians ordered sputum testing for tuberculosis and other bacteria, 9% of all patients and 33% of tuberculosis patients had tuberculosis and bacterial co-infection. Greater availability of microbiologic diagnostics for pulmonary tuberculosis and bacterial infection is critical to ensure appropriate diagnosis and management.

Reasons for late diagnostics of tuberculosis in adolescents

In total the authors reviewed 83 patient records: disease development anamnesis, results of the standard clinical, radiological and laboratory examinations. Tuberculosis in adolescents found during routine examination is characterized by a high epidemic risk (45% of patients were sputum positive), severe clinical forms of the disease with the pronounced residual abnormalities and therefore need of surgical treatments. Patients with the clinical signs of pulmonary disease (pneumonia, bronchitis, recurrent acute respiratory infections) belong to the risk group requiring evaluation for tuberculosis including with the use of immunological skin tests.

Operationalization of bi-directional screening for tuberculosis and diabetes in private sector healthcare clinics in Karachi, Pakistan

BackgroundMany countries are facing overlapping epidemics of tuberculosis (TB) and diabetes mellitus (DM). Diabetes increases the overall risk of developing Tuberculosis (TB) and contributes to adverse treatment outcomes. Active screening for both diseases can reduce TB transmission and prevent the development of complications of DM. We investigated bi-directional TB-DM screening in Karachi, Pakistan, a country that ranks fifth among high TB burden countries, and has the seventh highest country burden for DM.MethodsBetween February to November 2014, community-based screeners identified presumptive TB and DM through verbal screening at private health clinics. Individuals with presumptive TB were referred for a chest X-ray and Xpert MTB/RIF. Presumptive DM cases had random blood glucose (RBS) tested. All individuals with bacteriologically positive TB were referred for diabetes testing (RBS). All pre-diabetics and diabetics were referred for a chest X-ray and Xpert MTB/RIF test. The primary outcomes of this study were uptake of TB and DM testing.ResultsA total of 450,385 individuals were screened, of whom 18,109 had presumptive DM and 90,137 had presumptive TB. 14,550 of these individuals were presumptive for both DM and TB. The uptake of DM testing among those with presumptive diabetes was 26.1% while the uptake of TB testing among presumptive TB cases was 5.9%. Despite efforts to promote bi-directional screening of TB and DM, the uptake of TB testing among pre-diabetes and diabetes cases was only 4.7%, while the uptake of DM testing among MTB positive cases was 21.8%.ConclusionWhile a high yield for TB was identified among pre-diabetics and diabetics along with a high yield of DM among individuals diagnosed with TB, there was a low uptake of TB testing amongst presumptive TB patients who were recorded as pre-diabetic or diabetic. Bi-directional screening for TB and DM which includes the integration of TB diagnostics, DM screening and TB-DM treatment within existing health care programs will need to address the operational challenges identified before implementing this as a strategy in public health programs.

Automatic diagnostics of tuberculosis using convolutional neural networks analysis of MODS digital images.

Tuberculosis is an infectious disease that causes ill health and death in millions of people each year worldwide. Timely diagnosis and treatment is key to full patient recovery. The Microscopic Observed Drug Susceptibility (MODS) is a test to diagnose TB infection and drug susceptibility directly from a sputum sample in 7–10 days with a low cost and high sensitivity and specificity, based on the visual recognition of specific growth cording patterns of M. Tuberculosis in a broth culture. Despite its advantages, MODS is still limited in remote, low resource settings, because it requires permanent and trained technical staff for the image-based diagnostics. Hence, it is important to develop alternative solutions, based on reliable automated analysis and interpretation of MODS cultures. In this study, we trained and evaluated a convolutional neural network (CNN) for automatic interpretation of MODS cultures digital images. The CNN was trained on a dataset of 12,510 MODS positive and negative images obtained from three different laboratories, where it achieved 96.63 +/- 0.35% accuracy, and a sensitivity and specificity ranging from 91% to 99%, when validated across held-out laboratory datasets. The model's learned features resemble visual cues used by expert diagnosticians to interpret MODS cultures, suggesting that our model may have the ability to generalize and scale. It performed robustly when validated across held-out laboratory datasets and can be improved upon with data from new laboratories. This CNN can assist laboratory personnel, in low resource settings, and is a step towards facilitating automated diagnostics access to critical areas in developing countries.

The TAM-TB Assay-A Promising TB Immune-Diagnostic Test With a Potential for Treatment Monitoring.

Tuberculosis (TB) epidemiology is changing in Western and Central Europe due to the rise in immigration and refugees fleeing high-TB-burden areas of war and devastation. The change in local demography and the lack of sensitive and specific TB diagnostic and monitoring tools, especially for cases of childhood TB, leads to either missed cases or over-treatment of this group. Here we present a promising new diagnostic approach, the T cell activation marker (TAM)-TB assay, and its performance in a case of extra-pulmonary TB occurring in a 16 year old refugee from Afghanistan. This assay is based on the characterization of 3 activation markers (CD38, HLA-DR, and Ki67) and one maturation marker (CD27) on M. tuberculosis-specific CD4 T cells. It was performed at time-points T0 (10 days), T1 (1 month), T2 (6 months), and T3 (12 months) post-treatment initiation. All markers were able to detect active tuberculosis (aTB) within this patient at T0 and reverted to a healthy/LTBI phenotype at the end of treatment. Tantalizingly, there was a clear trend toward the healthy/LTBI phenotype for the markers at T1 and T2, indicating a potential role in monitoring anti-TB treatment in the future. This assay may therefore contribute to improved TB diagnostic algorithms and TB treatment monitoring, potentially allowing for individualization of TB treatment duration in the future.

Improved Diagnosis of Pulmonary Tuberculosis in Children Using Xpert Ultra on Nasopharyngeal and Induced Sputum Specimens

Rapid diagnosis of pulmonary TB (PTB) in children is desirable. We investigated the diagnostic accuracy of Xpert Ultra, a new rapid test, on repeated induced sputum (IS), nasopharyngeal aspirates (NPAs) and combinations of specimens. Methods: Consecutive South African children hospitalized with suspected PTB were enrolled. Two sequential paired IS and NPAs were obtained. NPAs were frozen; IS underwent liquid culture and an aliquot was frozen. Ultra was performed on thawed NPA and IS samples individually. Children were categorised as confirmed (culture positive), unconfirmed (clinically diagnosed) or unlikely TB (improvement without TB treatment) according to NIH case definitions. The diagnostic accuracy of Ultra was compared with liquid culture on IS. Findings: 195 children [median age 23·3 months, 32(16·4%) HIV-infected] had one IS and NPA; 130 had two NPAs. There were 40(20·5%) culture confirmed cases. Ultra was positive on NPAs in 26(13·3%) and on IS in 31(15·9%) respectively. Sensitivity and specificity of Ultra on one NPA were 45·7% and 97·5% respectively, similar by HIV status. Sensitivity and specificity of Ultra on one IS was 74·3% and 96·9% respectively. Combining one NPA and one IS increased sensitivity to 80%. Sensitivity using two Ultra NPAs was 54.2%, increasing to 87.5% with an IS Ultra. Interpretation: Induced sputum provides a better specimen than repeated NPAs for rapid diagnosis using Ultra, however, Ultra testing of combinations of specimens provides a novel strategy that can be adapted to different settings to identify most children with confirmed PTB. Funding Statement: RePORT TB Consortium, MRC South Africa, NIH (RO1HD058971) Declaration of Interests: FIND is a not-for-profit foundation that supports the evaluation of publicly prioritized tuberculosis assays and the implementation of WHO-approved (guidance and prequalification) assays using donor grants. FIND has product evaluation agreements with several private sector companies that design diagnostics for tuberculosis and other diseases. These agreements strictly define FIND’s independence and neutrality vis-a-vis the companies whose products get evaluated and describe roles and responsibilities. Ethics Approval Statement: The study was approved by the Research Ethics Committee of the Faculty of Health Sciences, University of Cape Town.

Challenges and opportunities for eliminating tuberculosis \u2013 leveraging political momentum of the UN high-level meeting on tuberculosis

BackgroundAs demonstrated by the United Nations High-Level Meeting on tuberculosis (TB) held in September 2018, the political momentum for TB has been increasing. The aim of this study was to analyze the current challenges and opportunities for global TB control and, with specific focus on policies surrounding TB control, to reveal what kinds of efforts are needed to accelerate global TB control.MethodsWe organized two expert meetings with the purposes of assessing the current situation and analyzing challenges regarding TB control. By applying Shiffman and Smith’s framework which contains four categories; Actor, Ideas, Political context, and Issue characteristics, we analyzed the challenges and opportunities for global TB control based on the findings from the two expert meetings.ResultsIn the Actor Category, we found that although there has already been active engagement by non-governmental organizations (NGOs), civil society organizations (CSOs) and private sectors, there still remained an area with room for improvement. In particular, the complexities behind varying drug regulatory and procurement systems per country hindered the active participation of the private sector in this area. As for the Ideas category, due to an increasing threat of antimicrobial resistance and growing number of global migrations, TB is now widely recognized as a health security issue rather than a purely health issue. This makes TB an easier target for political attention. As for the Political category, having the UN High-Level Meeting itself is not enough; such meetings must be followed up by actual commitments from heads of states. Lastly the issue characteristic indicates that the amount of funding for R&D for new drugs, vaccines and diagnostics for TB is not at an adequate level, and investment in childhood TB and missing cases are particularly in need.ConclusionsThis study provides important insight into the current status of global efforts toward end TB epidemic. The outcomes from the UN high-level meeting on TB need to be closely monitored will be crucial for the progress towards this goal.

Innovations in tuberculosis diagnostics: How far are we from reaching our goal?

Innovations in tuberculosis diagnostics: How far are we from reaching our goal?

Diagnosis of TB: From conventional to modern molecular protocols.

Tuberculosis (TB) is an infectious disease caused by different strains of Mycobacterium tuberculosis complex. TB is a curable infection if diagnosed correctly and timely. Late diagnosis and improper treatment may lead to relapse or its escalation to MDR / XDR-TB. TB with HIV co-infection is difficult to diagnose by conventional set-up. Also, detection of child TB and extrapulmonary TB has its own set of problems and is not straightforward to diagnose. The increasing complexity of TB due to the advent of new circulating strains and invasion to the regions where it was non-existent or thought to be eradicated is putting a severe strain on the health management services and making it an unmanageable pandemic. This increasing complexity has led to the spurt in the development of TB diagnostics platforms. This review focuses on the new emerging technologies that have changed the diagnostics landscape.

A bioinformatics analysis of exosomal microRNAs released following mycobacterial infection.

Tuberculosis (TB) still remains a major health threat worldwide. The current TB diagnostics are suboptimal, and there is a high clinical need for identifying novel biomarkers of disease prevalence. Circulating exosomes have been currently attractive as novel biomarkers in a wide range of pathological conditions. In this study, we performed bioinformatics analysis on the downstream targets of a dysregulated microRNA (miRNA) cluster induced by Bacillus Calmette-Guerin infection of human macrophages to provide greater understanding of their potential roles in disease pathogenesis. Our analysis demonstrated that these dysregulated miRNAs have central roles in the host metabolic and energy pathways. This suggests that the host miRNA network is perturbed by Mycobacterium to re-patterning host metabolism machinery to favor its intracellular survival. The dysregulated miRNAs can be delivered to local and distal cells by exosomes and thereby modulate their function.

Nanoparticle-Based Biosensing of Tuberculosis, an Affordable and Practical Alternative to Current Methods

Access to community-based point-of-care, low-cost, and sensitive tuberculosis (TB) diagnostics remains an unmet need. Objective: The objective of this study was to combine principles in nanotechnology, TB biology, glycochemistry, and engineering, for the development of a nanoparticle-based colorimetric biosensing assay (NCBA) to quickly and inexpensively detect acid-fast bacilli (AFB) in sputum samples. Methods: In NCBA, the isolation of AFB from sputum samples was accomplished through glycan-coated magnetic nanoparticles (GMNP) interacting with AFB and then using a simple magnet to separate the GMNP-AFB complex. Acid-fastness and cording properties of mycobacteria were utilized to provide visually observable red-stained clumps of bacteria that were surrounded by brown nanoparticles under a light microscope on prepared smears. The NCBA technique was compared against sputum smear microscopy (SSM) and Xpert MTB/RIF in 500 samples from patients that were suspected to have TB. Results: Statistical analysis showed that NCBA had sensitivity and specificity performances in perfect agreement with Xpert MTB/RIF as gold standard for all 500 samples. SSM had a sensitivity of 40% for the same samples. Conclusion: NCBA technique yielded full agreement in terms of sensitivity and specificity with the Xpert MTB/RIF in 500 samples. The method is completed in 10–20 min through a simple process at an estimated cost of $0.10 per test. Implementation of NCBA in rural communities would help to increase case finding and case notification, and would support programs against drug-resistance. Its use at the first point-of-contact by patients in the healthcare system would facilitate quick treatment in a single clinical encounter, thus supporting the global “End TB Strategy” by 2035.

Identification of HLA-A2-Restricted Mycobacterial Lipoprotein Z Peptides Recognized by T CellsFrom Patients With ActiveTuberculosis Infection.

Identification of HLA-restricted peptides derived from mycobacterial antigens that are endowed with high affinity and strong antigenicity is not only of interest in tuberculosis (TB) diagnostics and treatment efficacy evaluation, but might also provide potential candidates for the development of therapeutic vaccines against drug-resistant TB. Our previous work demonstrated that lipoprotein Z (LppZ) displayed high immunogenicity and antigenicity in active TB patients. In the present study, ten HLA-A2-restricted LppZ peptides (LppZp1-10) were predicted by bioinformatics, among which LppZp7 and LppZp10 were verified to possess high affinity to HLA-A2 molecules using T2 cell-based affinity binding assay. Moreover, results from ELISpot assay showed that both LppZp7 and LppZp10 peptides were able to induce more IFN-γ producing cells upon ex vivo stimulation of PBMC from HLA-A2+ active TB (ATB) patients as compared to those from healthy controls (HCs). Also, the numbers of LppZp7 and LppZp10-specific IFN-γ producing cells exhibited positive correlations with those of ESAT-6 peptide (E6p) or CFP-10 peptide (C10p) in ATB. Interestingly, stimulation with LppZp7/p10 mixture was able to induce higher intracellular expression of IFN-γ and IL-2 cytokines in CD8+ and CD4+ T cells from ATB as compared to HC, associated with lower expression of TNF-α in both CD8+ and CD4+ T cells. Taken together, HLA-A2-restricted LppZp7 and LppZp10 peptides display high immunoreactivity in HLA-matched ATB patients demonstrated by high responsiveness in both CD8+ and CD4+ T cells. With the ability to induce strong antigen-specific cellular responses, LppZp7 and LppZp10 are of potential value for the future applications in the prevention and control of TB.

The modern characteristic of biology and diagnostics prospect M. tuberculosis

Features of biology M. tuberculosis are considered the including modern data about features of morphology, the antigen structures of the various nature defining virulence of activators of tuberculosis. Based on the method data spoligothipirovanie genetic distinctions of families Mycobacteriaceae, and among them strains genotype Beijing, different by wide prevalence in the Russian Federation and high medicinal stability are especially characterised. Based on difficult antigens structure M. tuberculosis features of the development of the immune answer which allow predicting a current of the infectious process are reflected. The presented characteristics reflect considerable heterogeneity strains M. tuberculosis which is combined with a variety of an immune homeostasis of the carriers which were ill and by that essentially complicates laboratory diagnostics of tuberculosis. Among the considered modern methods of diagnostics of a tubercular infection, the most perspective can be immunologic. One of the ways of improvement serodiagnostic the tests promoting an increase of sensitivity serodiagnostic of tuberculosis is creation polyepitopes chimeric antigens by chemical synapsis fibres with carbohydrate molecules. Creation of a composition from several immunodominant antigens M. tuberculosis can become other direction of increase of sensitivity. that will allow lowering considerably number false-positive results. Creation of hybrid fibers will allow avoiding an inevitable decrease in affinity of antibodies of the way of the blood, arising at the use of several antigens simultaneously.

Differential detection of tuberculous and non-tuberculous mycobacteria by qPCR in lavage fluids of tuberculosis-suspicious white rhinoceros.

Tuberculosis (TB) occurs in a wide range of mammalian species and thus poses a health risk to humans living or working in close proximity with TB infected animals. Despite a high incidence of M. bovis infections in domestic or wildlife species tuberculosis infections in rhinoceros have so far been very limited. Over the past 53 years, tuberculosis of the respiratory tract has been confirmed in just 22 rhinoceros, most of those infected not by M. bovis but M. tuberculosis. However, because of the zoonotic risk TB testing is recommended or becomes even mandatory in endangered species. The dilemma in rhinoceros and many other wildlife species; non-validated tests are highly inconsistent in their ability to identify TB infection. Current lack of TB diagnostics may result in TB positive rhinoceros living with the infection, transmitting it to those around them or in euthanasia of animals found unconfirmed at necropsy. This is an unacceptable diagnostic status considering that some species are critically endangered and therefore should not be euthanized in order to confirm suspicion of disease. To overcome this shortcoming we used bronchoscopy to detect mycobacteria in respiratory fluids of TB suspicious rhinoceros. Fluids from seven, TB suspicious white rhinoceros were harvested during 21 bronchoscopies. Our new approach: In addition to bacterial culture a dual quantitative PCR system tested for the general presence of DNA from NTM and more specifically for DNA from MTC. Both, bacterial culture and qPCR were negative for MTC in respiratory fluids of all rhinoceros (7/7). At the same time, respiratory fluids from six rhinoceros tested positive for the presence of NTM or other closely related bacteria (6/7). M. tuberculosis was found only once in an oesophageal aspirate. The high incidence of mycobacterial DNA in the respiratory tract suggests that white rhinoceros, as strict grazers, are immensely exposed to environmental bacteria of this genus. Presence of NTM in the respiratory or intestinal system could possibly cause false positive results in intradermal tests. A wider use of bronchoalveolar lavage is warranted to further elucidate immunologic response to NTM and exposure to, incidence and prevalence of MTC infections in rhinoceros.

2000. Rapid, Point-of-care Diagnosis of Tuberculosis with Novel Truenat Assay: Cost-Effectiveness and Budgetary Impact Analysis for India’s Public Sector

BackgroundPoint-of-care (POC) tuberculosis (TB) diagnostics may dramatically improve TB outcomes. Truenat is a new, battery-powered RT-PCR device that rapidly detects TB and rifampin resistance. Due to its portability, it may be valuable in peripheral healthcare settings. We evaluated the cost-effectiveness of Truenat in peripheral laboratories (designated microscopy centres [DMCs]) and public healthcare facilities in India.MethodsWe used the CEPAC-International microsimulation model to compare four TB diagnostic strategies for adult, HIV-negative patients with suspected TB: (1) sputum smear microscopy in DMCs (SSM); (2) Xpert MTB/RIF in DMCs (Xpert); (3) Truenat in DMCs (Truenat DMC); and (4) Truenat in public healthcare facilities (Truenat POC). We projected life expectancy (LE), costs, incremental cost-effectiveness ratios (ICERs), and 5y budget impact of full scale-up. A strategy was cost-effective if its ICER was <US$990/year of life saved (YLS) (i.e., <50% of India annual per capita GDP). Model inputs included: TB prevalence, 20%; sensitivity for TB detection, 92% for Xpert and 89% for Truenat; costs per test, $12.70 for Xpert and $13.20 for Truenat; linkage to care after diagnosis, 84% for DMC-based tests and 95% for POC. We varied these parameters in sensitivity analyses.ResultsCompared with SSM, other strategies increased TB case detection by >6%; Truenat POC increased LE by ~0.3 years with ICER $210/YLS (Table 1). Compared with Xpert, Truenat DMC decreased LE and cost, but Truenat POC improved LE by 0.05 years and was cost-effective. In multi-way sensitivity analysis at 5 years horizon, Truenat POC, at 89% diagnostic sensitivity and linkage to care >86%, was cost-effective and sometimes cost-saving compared with Xpert (Figure 1). The cost-effectiveness of Truenat, relative to Xpert, depended on the interplay of sensitivity and linkage to care. Public-sector implementation of Truenat POC increased healthcare expenditures by $360 million compared with full scale-up of Xpert (Figure 2). Treatment costs, not diagnostic test costs, accounted for most of the difference. ConclusionWhen used at the point of care, Truenat for TB diagnosis should improve linkage to care, increase LE, and be cost-effective compared with SSM or Xpert and, thus, should be more widely utilized in India.Disclosures All authors: No reported disclosures.

Design and protocol for a pragmatic randomised study to optimise screening, prevention and care for tuberculosis and HIV in Malawi (PROSPECT Study).

Background: Adults seeking diagnosis and treatment for tuberculosis (TB) and HIV in low-resource settings face considerable barriers and have high pre-treatment mortality. Efforts to improve access to prompt TB treatment have been hampered by limitations in TB diagnostics, with considerable uncertainty about how available and new tests can best be implemented. Design and methods: The PROSPECT Study is an open, three-arm pragmatic randomised study that will investigate the effectiveness and cost-effectiveness of optimised HIV and TB diagnosis and linkage to care interventions in reducing time to TB diagnosis and prevalence of undiagnosed TB and HIV in primary care in Blantyre, Malawi. Participants (≥ 18 years) attending a primary care clinic with TB symptoms (cough of any duration) will be randomly allocated to one of three groups: (i) standard of care; (ii) optimised HIV diagnosis and linkage; or (iii) optimised HIV and TB diagnosis and linkage. We will test two hypotheses: firstly, whether prompt linkage to HIV care should be prioritised for adults with TB symptoms; and secondly, whether an optimised TB triage testing algorithm comprised of digital chest x-ray evaluated by computer-aided diagnosis software and sputum GeneXpert MTB/Rif can outperform clinician-directed TB screening. The primary trial outcome will be time to TB treatment initiation by day 56, and secondary outcomes will include prevalence of undiagnosed TB and HIV, mortality, quality of life, and cost-effectiveness. Conclusions: The PROSPECT Study will provide urgently-needed evidence under "real-life" conditions to inform clinicians and policy makers on how best to improve TB/HIV diagnosis and treatment in Africa. Clinical trial registration: NCT03519425 (08/05/2018).

Exhaled human breath analysis in active pulmonary tuberculosis diagnostics by comprehensive gas chromatography-mass spectrometry and chemometric techniques

Tuberculosis (TB) is the deadliest infectious disease, and yet accurate diagnostics for the disease are unavailable for many subpopulations. In this study, we investigate the possibility of using human breath for the diagnosis of active TB among TB suspect patients, considering also several risk factors for TB for smokers and those with human immunodeficiency virus (HIV). The analysis of exhaled breath, as an alternative to sputum-dependent tests, has the potential to provide a simple, fast, non-invasive, and readily available diagnostic service that could positively change TB detection. A total of 50 individuals from a clinic in South Africa were included in this pilot study. Human breath has been investigated in the setting of active TB using the thermal desorption-comprehensive two-dimensional gas chromatography–time of flight mass spectrometry methodology and chemometric techniques. From the entire spectrum of volatile metabolites in breath, three machine learning algorithms (support vector machines, partial least squares discriminant analysis, and random forest) to select discriminatory volatile molecules that could potentially be useful for active TB diagnosis were employed. Random forest showed the best overall performance, with sensitivities of 0.82 and 1.00 and specificities of 0.92 and 0.60 in the training and test data respectively. Unsupervised analysis of the compounds implicated by these algorithms suggests that they provide important information to cluster active TB from other patients. These results suggest that developing a non-invasive diagnostic for active TB using patient breath is a potentially rich avenue of research, including among patients with HIV comorbidities.

Coordinating the prevention, treatment, and care continuum for HIV-associated tuberculosis in prisons: a health systems strengthening approach.

To advance a re-conceptualized prevention, treatment, and care continuum (PTCC) for HIV-associated tuberculosis (TB) in prisons, and to make recommendations for strengthening prison health systems and reducing HIV-associated TB morbidity and mortality throughout the cycle of pretrial detention, incarceration, and release. Despite evidence of increased HIV-associated TB burden in prisons compared to the general population, prisoners face entrenched barriers to accessing anti-TB therapy, antiretroviral therapy, and evidence-based HIV and TB prevention. New approaches, suitable for the complexities of healthcare delivery in prisons, have emerged that may address these barriers, and include: novel TB diagnostics, universal test and treat for HIV, medication-assisted treatment for opioid dependence, comprehensive transitional case management, and peer navigation, among others. Realizing ambitious international HIV and TB targets in prisons will only be possible by first addressing the root causes of the TB/HIV syndemic, which are deeply intertwined with human rights violations and weaknesses in prison health systems, and, second, fundamentally re-organizing HIV and TB services around a coordinated PTCC. Taking these steps can help ensure universal access to comprehensive, good-quality, free and voluntary TB/HIV prevention, treatment, and care, and advance efforts to strengthen health resourcing, staffing, information management, and primary care access within prisons.

Diagnosis of HIV-associated tuberculosis.

The current review highlights recent advances in tuberculosis (TB) diagnostics that are relevant for clinicians engaged in the care of HIV-positive adults. The first section focuses on newly available tools, highlighting recent progress. The second section focuses on new diagnostic approaches that are not yet widely available or implemented, but have considerable potential to improve the management of TB/HIV coinfected persons. The final section speculates about future directions that may be fruitful. Advances in Mycobacterium tuberculosis nucleic acid amplification-based genotypic tests stand to improve case detection and drug susceptibility testing in the near term. Identification of human gene expression signatures that are associated with TB and/or TB risk, and the identification of novel M. tuberculosis targets coupled with exploitation of advances in biosensor technology may transform TB diagnosis in the future.