Scale-up of services and research priorities for diagnosis, management, and control of tuberculosis: a call to action

Transcriptional profiling of human peripheral blood mononuclear cells in household contacts of pulmonary tuberculosis patients provides insights into mechanisms of Mycobacterium tuberculosis control and elimination

Household contacts (HHCs) of patients with active tuberculosis (ATB) are at higher risk of Mycobacterium tuberculosis (M. tuberculosis) infection. However, the immune factors responsible for different defense responses in HHCs are unknown. Hence, we aimed to evaluate transcriptome signatures in human peripheral blood mononuclear cells (PBMCs) of HHCs to aid risk stratification. We recruited 112 HHCs of ATB patients and followed them for 6 years. Among the HHCs, only 2 developed ATB, while the remaining HHCs were classified into three groups: (1) HHC-1 group (n = 23): HHCs with consistently positive T-SPOT.TB test, negative chest radiograph, and no clinical symptoms or evidence of ATB during the 6-year follow-up period; (2) HHC-2 group (n = 15): HHCs with an initial positive T-SPOT result that later became negative without evidence of ATB; (3) HHC-3 group (n = 14): HHCs with a consistently negative T-SPOT.TB test and no clinical or radiological evidence of ATB. HHC-2 and HHC-3 were combined as HHC-23 group for analysis. RNA sequencing (RNA-seq) in PBMCs, with and without purified protein derivative (PPD) stimulation, identified significant differences in gene signatures between HHC-1 and HHC-23. Gene ontology analysis revealed functions related to bacterial pathogens, leukocyte chemotaxis, and inflammatory and cytokine responses. Modules associated with clinical features in the HHC-23 group were linked to the IL-17 signaling pathway, ferroptosis, complement and coagulation cascades, and the TNF signaling pathway. Validation using real-time PCR confirmed key genes like ATG-7, CXCL-3, and TNFRSF1B associated with infection outcomes in HHCs. Our research enhances understanding of disease mechanisms in HHCs. HHCs with persistent latent tuberculosis infection (HHC-1) showed significantly different gene expression compared to HHCs with no M. tuberculosis infection (HHC-23). These findings can help identify HHCs at risk of developing ATB and guide targeted public health interventions.

Global burden of MDR-TB and XDR-TB attributable to high fasting plasma glucose from 1990 to 2019: a retrospective analysis based on the global burden of disease study 2019

PURPOSE

High fasting plasma glucose (HFPG) has been identified as a risk factor for drug-resistant tuberculosis incidence and mortality. However, the epidemic characteristics of HFPG-attributable multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) remain unclear. We aimed to analyze the global spatial patterns and temporal trends of HFPG-attributable MDR-TB and XDR-TB from 1990 to 2019.

METHODS

Utilizing data from the Global Burden of Disease 2019 project, annual deaths and disability-adjusted life years (DALYs) of HFPG-attributable MDR-TB and XDR-TB were conducted from 1990 to 2019. Joinpoint regression was employed to quantify trends over time.

RESULTS

From 1990 to 2019, the deaths and DALYs due to HFPG-attributable MDR-TB and XDR-TB globally showed an overall increasing trend, with a significant increase until 2003 to 2004, followed by a gradual decline or stability thereafter. The low sociodemographic index (SDI) region experienced the most significant increase over the past 30 years. Regionally, Sub-Saharan Africa, Central Asia and Oceania remained the highest burden. Furthermore, there was a sex and age disparity in the burden of HFPG-attributable MDR-TB and XDR-TB, with young males in the 25-34 age group experiencing higher mortality, DALYs burden and a faster increasing trend than females. Interestingly, an increasing trend followed by a stable or decreasing pattern was observed in the ASMR and ASDR of HFPG-attributable MDR-TB and XDR-TB with SDI increasing.

CONCLUSION

The burden of HFPG-attributable MDR-TB and XDR-TB rose worldwide from 1990 to 2019. These findings emphasize the importance of routine bi-directional screening and integrated management for drug-resistant TB and diabetes.

The development of the national tuberculosis research priority in Indonesia: A comprehensive mixed-method approach

Ranked second in global tuberculosis (TB) incidence, Indonesia has developed a National Strategy for TB Prevention and Control 2020-2024 to accelerate the TB elimination program. Research and innovation are key pillars to support the program and need to be prioritised. This study aimed to develop updated national TB research priorities in Indonesia. This study was a mixed-methods study consisting of an open survey, a published literature survey, and Delphi survey. The open survey invited all related TB stakeholders to answer (a) the main barriers of the TB program and (b) the need for studies to support TB elimination. The published literature survey retrieved scientific articles published in national and international journals between 2015 and 2020 to identify gaps between published research and the current national strategy for TB control. The online survey and literature survey informed a panel of TB experts in a two-phase Delphi Survey to select the top 10 priority research topics. We identified 322 articles and analysed 1143 open survey responses. Through two-phases Delphi surveys, top ten research categories were listed: early TB detection; diagnosis and treatment of DR-TB; contact investigation; case detection and treatment of child TB; TB preventive therapy; government policy; laboratory for drug-sensitive- and drug-resistant-TB diagnosis; treatment adherence; diagnostic tool development; and community empowerment. This study also found the gap between stakeholders' interests and the importance of translating research into policy and practice. TB research priorities have been identified through the involvement of various stakeholders. The combination of an online survey, a published literature survey, and a Delphi survey was a rigorous methodology and was fit to build a systematic consensus about the priority of TB research.

A Current Perspective on the Potential of Nanomedicine for Anti-Tuberculosis Therapy

Tuberculosis (TB) is one of the ten infectious diseases that cause the highest amount of human mortality and morbidity. This infection, which is caused by a single pathogen, Mycobacterium tuberculosis, kills over a million people every year. There is an emerging problem of antimicrobial resistance in TB that needs urgent treatment and management. Tuberculosis treatment is complicated by its complex drug regimen, its lengthy duration and the serious side-effects caused by the drugs required. There are a number of critical issues around drug delivery and subsequent intracellular bacterial clearance. Drugs have a short lifespan in systemic circulation, which limits their activity. Nanomedicine in TB is an emerging research area which offers the potential of effective drug delivery using nanoparticles and a reduction in drug doses and side-effects to improve patient compliance with the treatment and enhance their recovery. Here, we provide a minireview of anti-TB treatment, research progress on nanomedicine and the prospects for future applications in developing innovative therapies.

Treatment Outcomes of Childhood TB Patients in Four TB High Burden States of Malaysia: Results from a Multicenter Retrospective Cohort Study

Data regarding treatment outcomes among childhood TB patients are lacking in Malaysia. The present study aimed to evaluate the treatment outcomes and predictors of unsuccessful treatment outcomes among childhood TB patients in four TB high-burden states of Malaysia. This was a retrospective cohort study conducted at 13 healthcare centers in four states of Malaysia, namely, Sabah, Sarawak, Selangor, and Penang. During the study period, a total of 8932 TB patients were enrolled for treatment at the study sites, of whom 206 (2.31%) were children. The majority of the childhood TB patients were female (52.9%) and belonged to the age group of 6–10 years (42.7%). Pulmonary TB accounted for 70.9% of childhood TB. Among childhood PTB patients, 50% were sputum smear negative. One hundred and seventy-eight patients (86.4%) were successfully treated (87 were cured and 91 completed treatment). Among 28 (13.6%) patients with unsuccessful treatment outcomes, 13 (6.3%) died, 3 (1.5%) failed treatment, 9 (4.4%) defaulted, and 3 (1.5%) were transferred out. Multivariate analysis revealed that patients’ age (5–14 years) (OR = 0.279, p-value = 0.006) and male gender (OR = 0.390, p-value = 0.046) had a statistically significant negative association with unsuccessful treatment outcomes. The prevalence of childhood TB in the current study was comparable to the recently published national estimates. The study sites reached the WHO target of treatment success. Special attention to patients with identified risk factors can improve treatment outcomes.

Blue Skies research is essential for ending the Tuberculosis pandemic and advancing a personalized medicine approach for holistic management of Respiratory Tract infections

OBJECTIVES

Investments into 'Blue Skies' fundamental TB research in low- and middle-income countries (LMICs) have not been forthcoming. We highlight why blue skies research will be essential for achieving global TB control and eradicating TB.

METHODS

We review the historical background to early TB discovery research and give examples of where investments into basic science and fundamental 'blue skies research' are delivering novel data and approaches to advance diagnosis, management and holistic care for patients with active and latent TB infection.

FINDINGS

The COVID-19 pandemic has shown that making available adequate funding for priority investments into 'Blue skies research' to delineate scientific understanding of a new infectious diseases threat to global health security can lead to rapid development and rollout of new diagnostic platforms, treatments, and vaccines. Several advances in new TB diagnostics, new treatments and vaccine development are underpinned by basic science research.

CONCLUSIONS

Blue Skies research is required to pave the way for a personalized medicine approach for management of TB and other Respiratory Tract Infections and preventing long-term functional disability. Transfer of skills and resources by wealthier nations is required to empower researchers in LMICs countries to engage in and lead Blue Skies research.

MDR Tuberculosis Treatment

Multidrug-resistant (MDR) tuberculosis (TB), resistant to isoniazid and rifampicin, continues to be one of the most important threats to controlling the TB epidemic. Over the last few years, there have been promising pharmacological advances in the paradigm of MDR TB treatment: new and repurposed drugs have shown excellent bactericidal and sterilizing activity against Mycobacterium tuberculosis and several all-oral short regimens to treat MDR TB have shown promising results. The purpose of this comprehensive review is to summarize the most important drugs currently used to treat MDR TB, the recommended regimens to treat MDR TB, and we also summarize new insights into the treatment of patients with MDR TB.

Durations of asymptomatic, symptomatic, and care-seeking phases of tuberculosis disease with a Bayesian analysis of prevalence survey and notification data

BACKGROUND

Ratios of bacteriologically positive tuberculosis (TB) prevalence to notification rates are used to characterise typical durations of TB disease. However, this ignores the clinical spectrum of tuberculosis disease and potentially long infectious periods with minimal or no symptoms prior to care-seeking.

METHODS

We developed novel statistical models to estimate progression from initial bacteriological positivity including smear conversion, symptom onset and initial care-seeking. Case-detection ratios, TB incidence, durations, and other parameters were estimated by fitting the model to tuberculosis prevalence survey and notification data (one subnational and 11 national datasets) within a Bayesian framework using Markov chain Monte Carlo methods.

RESULTS

Analysis across 11 national datasets found asymptomatic tuberculosis durations in the range 4-8 months for African countries; three countries in Asia (Cambodia, Lao PDR, and Philippines) showed longer durations of > 1 year. For the six countries with relevant data, care-seeking typically began half-way between symptom onset and notification. For Kenya and Blantyre, Malawi, individual-level data were available. The sex-specific durations of asymptomatic bacteriologically-positive tuberculosis were 9.0 months (95% credible interval [CrI]: 7.2-11.2) for men and 8.1 months (95% CrI: 6.2-10.3) for women in Kenya, and 4.9 months (95% CrI: 2.6-7.9) for men and 3.5 months (95% CrI: 1.3-6.2) for women in Blantyre. Age-stratified analysis of data for Kenya showed no strong age-dependence in durations. For Blantyre, HIV-stratified analysis estimated an asymptomatic duration of 1.3 months (95% CrI: 0.3-3.0) for HIV-positive people, shorter than the 8.5 months (95% CrI: 5.0-12.7) for HIV-negative people. Additionally, case-detection ratios were higher for people living with HIV than HIV-negative people (93% vs 71%).

CONCLUSION

Asymptomatic TB disease typically lasts around 6 months. We found no evidence of age-dependence, but much shorter durations among people living with HIV, and longer durations in some Asian settings. To eradicate TB transmission, greater gains may be achieved by proactively screening people without symptoms through active case finding interventions.

Convergence of infectious and non-communicable disease epidemics in rural South Africa: a cross-sectional, population-based multimorbidity study

BACKGROUND

There has been remarkable progress in the treatment of HIV throughout sub-Saharan Africa, but there are few data on the prevalence and overlap of other significant causes of disease in HIV endemic populations. Our aim was to identify the prevalence and overlap of infectious and non-communicable diseases in such a population in rural South Africa.

METHODS

We did a cross-sectional study of eligible adolescents and adults from the Africa Health Research Institute demographic surveillance area in the uMkhanyakude district of KwaZulu-Natal, South Africa. The participants, who were 15 years or older, were invited to participate at a mobile health camp. Medical history for HIV, tuberculosis, hypertension, and diabetes was established through a questionnaire. Blood pressure measurements, chest x-rays, and tests of blood and sputum were taken to estimate the population prevalence and geospatial distribution of HIV, active and lifetime tuberculosis, elevated blood glucose, elevated blood pressure, and combinations of these.

FINDINGS

17 118 adolescents and adults were recruited from May 25, 2018, to Nov 28, 2019, and assessed. Overall, 52·1% (95% CI 51·3-52·9) had at least one active disease. 34·2% (33·5-34·9) had HIV, 1·4% (1·2-1·6) had active tuberculosis, 21·8% (21·2-22·4) had lifetime tuberculosis, 8·5% (8·1-8·9) had elevated blood glucose, and 23·0% (22·4-23·6) had elevated blood pressure. Appropriate treatment and optimal disease control was highest for HIV (78·1%), and lower for elevated blood pressure (42·5%), active tuberculosis (29·6%), and elevated blood glucose (7·1%). Disease prevalence differed notably by sex, across age groups, and geospatially: men had a higher prevalence of active and lifetime tuberculosis, whereas women had a substantially high prevalence of HIV at 30-49 years and an increasing prevalence of multiple and poorly controlled non-communicable diseases when older than 50 years.

INTERPRETATION

We found a convergence of infectious and non-communicable disease epidemics in a rural South African population, with HIV well treated relative to all other diseases, but tuberculosis, elevated blood glucose, and elevated blood pressure poorly diagnosed and treated. A public health response that expands the successes of the HIV testing and treatment programme to provide multidisease care targeted to specific populations is required to optimise health in such settings in sub-Saharan Africa.

FUNDING

Wellcome Trust, Bill & Melinda Gates Foundation, the South African Department of Science and Innovation, South African Medical Research Council, and South African Population Research Infrastructure Network.

TRANSLATION

For the isiZulu translation of the abstract see Supplementary Materials section.

Trends in burden of multidrug-resistant tuberculosis in countries, regions, and worldwide from 1990 to 2017: results from the Global Burden of Disease study

Background

Antituberculosis-drug resistance is an important public health issue, and its epidemiological patterns has dramatically changed in recent decades. This study aimed to estimate the trends of multidrug-resistant tuberculosis (MDR-TB), which can be used to inform health strategies.

Methods

Data were collected from the Global Burden of Disease study 2017. The estimated annual percentage changes (EAPCs) were calculated to assess the trends of MDR-TB burden at global, regional, and national level from 1990 to 2017 using the linear regression model.

Results

Globally, the age-standardized rate (ASR) of MDR-TB burden including incidence, prevalence, death and disability-adjusted life years (DALYs) had pronounced increasing trends from 1990 to 1999, with the EAPCs were 17.63 [95% confidence interval (CI): 10.77–24.92], 17.57 (95% CI 11.51–23.95), 21.21 (95% CI 15.96–26.69), and 21.90 (95% CI 16.55–27.50), respectively. Particularly, the largest increasing trends were seen in areas and countries with low and low-middle sociodemographic index (SDI). However, the trends in incidence, prevalence, death and DALYs of MDR-TB decreased globally from 2000 to 2017, with the respective EAPCs were − 1.37 (95% CI − 1.62 to − 1.12), − 1.32 (95% CI − 1.38 to − 1.26), − 3.30 (95% CI − 3.56 to − 3.04) and − 3.32 (95% CI − 3.59 to − 3.06). Decreasing trends of MDR-TB were observed in most regions and countries, particularly that of death and DALYs in Slovenia were − 18.96 (95% CI − 20.82 to − 17.06) and -19.35 (95% CI − 21.10 to − 17.55), respectively. Whereas the pronounced increasing trends of MDR-TB occurred in Papua New Guinea, Singapore, and Australia.

Conclusions

The ASR of MDR-TB showed pronounced decreasing trends from 2000 to 2017. However, the MDR-TB burden remains a substantial challenge to the TB control globally, and requires effective control strategies and healthcare systems.

Performance of the Roche cobas MTB Assay for the Molecular Diagnosis of Pulmonary Tuberculosis in a High HIV Burden Setting

Increased access to and improved sensitivities of methods for diagnosing Mycobacterium tuberculosis infection and detecting rifampicin and isoniazid resistance are needed. Herein, the performance of the new cobas MTB assay for use on cobas 6800/8800 Systems (Roche) was assessed and compared with two other commercial assays: RealTime MTB (Abbott), and Xpert MTB/RIF (Cepheid). Molecular PCR-based assays were conducted on sputum specimens from individuals with presumptive and confirmed tuberculosis (n = 294) from two clinical facilities in South Africa between December 2016 and October 2017. Liquid mycobacterial culture was the reference. Test sensitivities were 94.7% (95% CI, 88%-98%), 92.6% (95% CI, 85%-97%), and 91.6% (95% CI, 84%-96%) for cobas MTB, RealTime MTB, and Xpert MTB/RIF assays, respectively. cobas MTB sensitivity was unaffected by HIV coinfection (95.7%; 95% CI, 88%-99%; n = 176) and sediment testing (94.7%; 95% CI, 88%-98%). Sensitivities were 81.8% (95% CI, 60%-95%), 72.7% (95% CI, 50%-89%), and 72.7% (95% CI, 50%-89%) among smear-negative, culture-positive individuals (n = 221) for cobas MTB, RealTime MTB, and Xpert MTB/RIF assays, respectively. cobas MTB specificity was 95.7% (95% CI, 89%-99%) and 99% (95% CI, 94%-100%) among HIV coinfected and uninfected individuals, respectively. The cobas 6800/8800 system is already implemented in South Africa for high-throughput HIV viral load testing, making it suitable for integrated HIV/tuberculosis diagnostics.

Sex differences and HIV status of tuberculosis in adults at a rural hospital in southern Ethiopia: an 18-year retrospective cross-sectional study

Background

The aim of the study was to compare the epidemiology, clinical characteristics and treatment outcome of tuberculosis (TB), including HIV status, in women and men in southern rural Ethiopia.

Methods

We conducted a register-based retrospective cohort study covering the period from September 1998 to August 2015.

Result

We included records of 2252 registered TB patients: 1080 (48%) women and 1172 (52%) men. Median age was similar for women and men: 27.5 years and 25.0 years, respectively. Median weight in women was 43.0 kg (interquartile range IQR: 38.0, 49.0), significantly lower than in men (50.0 kg, IQR 44.0, 55.0; p = 0.01). Extrapulmonary TB was significantly more common in women than in men (34.1% versus 28.7%; p=0.006). Treatment outcomes were similar in both sexes: in 70.3% of women and 68.9% of men, TB mortality was slightly lower in women than men (4.7% vs. 6.5%; p=0.08). In patients with TB, female sex was independently associated with low weight (adjusted aOR: 0.91; 95% CI 0.90, 0.92), less mortality (aOR: 0.54; 95% CI 0.36, 0.81), and lymph node TB (aOR: 1.57; 95% CI 1.13, 2.19)

Conclusion

Lymph node TB was more common in women. Treatment outcomes were similar in both sexes, but women had a lower mortality rate.

Transcriptional Profiling of Human Peripheral Blood Mononuclear Cells Identifies Diagnostic Biomarkers That Distinguish Active and Latent Tuberculosis

Mycobacterium tuberculosis (M. tuberculosis) infection in humans can cause active disease or latent infection. However, the factors contributing to the maintenance of latent infection vs. disease progression are poorly understood. In this study, we used a genome-wide RNA sequencing (RNA-seq) approach to identify host factors associated with M. tuberculosis infection status and a novel gene signature that can distinguish active disease from latent infection. By RNA-seq, we characterized transcriptional differences in purified protein derivative (PPD)-stimulated peripheral blood mononuclear cells (PBMCs) among three groups: patients with active tuberculosis (ATB), individuals with latent TB infection (LTBI), and TB-uninfected controls (CON). A total of 401 differentially expressed genes enabled grouping of individuals into three clusters. A validation study by quantitative real-time PCR (qRT-PCR) confirmed the differential expression of TNFRSF10C, IFNG, PGM5, EBF3, and A2ML1 between the ATB and LTBI groups. Additional clinical validation was performed to evaluate the diagnostic performance of these five biomarkers using 130 subjects. The 3-gene signature set of TNFRSF10C, EBF3, and A2ML1 enabled correct classification of 91.5% of individuals, with a high sensitivity of 86.2% and specificity of 94.9%. Diagnostic performance of the 3-gene signature set was validated using a clinical cohort of 147 subjects with suspected ATB. The sensitivity and specificity of the 3-gene set for ATB were 82.4 and 92.4%, respectively. In conclusion, we detected distinct gene expression patterns in PBMCs stimulated by PPD depending on the status of M. tuberculosis infection. Furthermore, we identified a 3-gene signature set that could distinguish ATB from LTBI, which may facilitate rapid diagnosis and treatment for more effective disease control.

Patient predictors of health-seeking behaviour for persons coughing for more than two weeks in high-burden tuberculosis communities: the case of the Western Cape, South Africa

Background

This study aimed to analyse the patient predictors of health-seeking behaviour for persons coughing for more than 2 weeks to better understand this vulnerable and important population.

Methods

The study analysed data from a cohort study (SOCS - Secondary Outcome Cohort Study) embedded in a community randomised trial ZAMSTAR (Zambia and South Africa TB and AIDS Reduction Study) in eight high-burden TB communities in the Western Cape, South Africa. These datasets are unique as they contain TB-related data as well as data on health, health-seeking behaviour, lifestyle choices, employment, socio-economic status, education and stigma. We use uni- and multivariate logistic regressions to estimate the odds ratios of consulting for a cough (of more than 2 weeks duration) for a range of relevant patient predictors.

Results

Three hundred and forty persons consulted someone about their cough and this represents 37% of the 922 participants who reported coughing for more than 2 weeks. In the multivariate analysis, respondents of black ethnic origin (OR 1.99, 95% CI 1.28–3.12, P < 0.01), those with higher levels of education (OR 1.05 per year of education, 95% CI 1.00–1.10, P = 0.05), and older respondents (OR 1.02 per year, 95% CI 1.01–1.04, P < 0.01) had a higher likelihood of consulting for their chronic cough. Individuals who smoked (OR 0.63, 95% CI 0.45–0.88, P < 0.01) and those with higher levels of socio-economic status (OR 0.81, 95% CI 0.71–0.92, P < 0.01) were less likely to consult. We find no evidence of stigma playing a role in health-seeking decisions, but caution that this may be due to the difficulty of accurately and reliably capturing stigma due to, amongst other factors, social desirability bias.

Conclusions

The low levels of consultation for a cough of more than 2 weeks suggest that there are opportunities to improve case-finding. These findings on health-seeking behaviour can assist policymakers in designing TB screening and active case-finding interventions that are targeted to the characteristics of those with a chronic cough who do not seek care.

Electronic supplementary material

The online version of this article (10.1186/s12913-019-3992-6) contains supplementary material, which is available to authorized users.

The global tuberculosis epidemic and progress in care, prevention, and research: an overview in year 3 of the End TB era

Tuberculosis is the number one cause of death from infectious disease globally and drug-resistant forms of the disease are a major risk to global health security. On the occasion of World Tuberculosis Day (March 24, 2018), we provide an up-to-date review of the status of the tuberculosis epidemic, recommended diagnostics, drug treatments and vaccines, progress in delivery of care and prevention, progress in research and development, and actions needed to accelerate progress. This Review is presented in the context of the UN Sustainable Development Goals and WHO's End TB Strategy, which share the aim of ending the global tuberculosis epidemic. In 2016, globally there were an estimated 10·4 million new cases of tuberculosis, and 600 000 new cases with resistance to rifampicin (the most powerful first-line drug). All countries and age groups are affected by tuberculosis, but most cases (90%) in 2016 were in adults, and almost two-thirds were accounted for by seven countries: India, Indonesia, China, Philippines, Pakistan, South Africa, and Nigeria. The sex ratio (male to female) was 1·9 and 10% of patients with newly diagnosed tuberculosis were also HIV-positive. There were 1·7 million deaths from tuberculosis in 2016, including 0·4 million deaths among people co-infected with HIV (officially classified as deaths caused by HIV/AIDS). Progress in care and prevention means that the global mortality rate (deaths per 100 000 people per year) is decreasing by 3·4% per year and incidence (new cases per 100 000 people per year) is decreasing by 1·9% per year. From 2000 to 2016, the annual global number of tuberculosis deaths decreased by 24% and the mortality rate declined by 37%. Worldwide, an estimated 53 million deaths were averted through successful treatment. Nonetheless, major gaps in care and prevention remain. For example, the 6·3 million new cases of tuberculosis reported globally in 2016 represented only 61% of the estimated incidence; only one in five of the estimated number of people with drug-resistant tuberculosis was enrolled in treatment. Pipelines for new diagnostics, drugs, and vaccines are progressing, but slowly. Actions needed to accelerate progress towards global milestones and targets for reductions in the burden of tuberculosis disease set for 2020, 2025, 2030, and 2035 include closing coverage gaps in testing, reporting of cases, and overall access to health care, especially in countries that account for the largest share of the global gap; multisectoral efforts to reduce prevalence of major risk factors for infection and disease; and increased investment in research and development.

Are scientific research outputs aligned with national policy makers' priorities? A case study of tuberculosis in Cambodia

With funding for tuberculosis (TB) research decreasing, and the high global disease burden persisting, there are calls for increased investment in TB research. However, justification of such investments is questionable, when translation of research outputs into policy and health care improvements remains a challenge for TB and other diseases. Using TB in Cambodia as a case study, we investigate how evidence needs of national policy makers are addressed by topics covered in research publications. We first conducted a systematic review to compile all studies on TB in Cambodia published since 2000. We then identified priority areas in which evidence for policy and programme planning are required from the perspective of key national TB control stakeholders. Finally, results from the literature review were analysed in relation to the priority research areas for national policy makers to assess overlap and highlight gaps in evidence. Priority research areas were: TB-HIV co-infection; childhood TB; multidrug resistant TB (MDR-TB); and universal and equitable access to quality diagnosis and treatment. On screening 1687 unique papers retrieved from our literature search, 253 were eligible publications focusing on TB in Cambodia. Of these, only 73 (29%) addressed one of the four priority research areas. Overall, 30 (11%), five (2%), seven (2%) and 37 (14%) studies reported findings relevant to TB-HIV, childhood TB, MDR-TB and access to quality diagnosis and treatment respectively. Our analysis shows that a small proportion of the research outputs in Cambodia address priority areas for informing policy and programme planning. This case study illustrates that there is substantial room for improvement in alignment between research outputs and evidence gaps that national policy makers would like to see addressed; better coordination between researchers, funders and policy makers' on identifying priority research topics may increase the relevance of research findings to health policies and programmes.

Review on emergence of drug-resistant tuberculosis (MDR & XDR-TB) and its molecular diagnosis in Ethiopia

Tuberculosis (TB) remains a major global health problem and ranks as the second leading cause of death among deaths caused by infectious diseases worldwide. Although the availability of short-course regimens as first-line anti-tuberculosis drugs, the emergence of drug-resistant Mycobacterium tuberculosis strains pose a major challenge to the prevention and control efforts of national tuberculosis programs (NTPs). M. tuberculosis changes its cellular environment with the mechanisms that have been evolved since prehistoric times. The interactions between the bacteria and the host environment have been studied well. However, the studies at molecular level began to emerge recently including expression profiling of micro RNA (miRNA) and literature survey revealed that researchers find more information about their regulatory role in biological processes including immune response to infectious agents like mycobacteria. In developing countries, including Ethiopia, the burden of tuberculosis and or drug resistance profile of M. tuberculosis remains largely unexplored, mainly due to lack of quality controlled second-line laboratory tests and also lack of knowledge on molecular diagnostics. This review describes the disease etiology, pathogenesis, epidemiology, molecular mechanism and advanced molecular diagnostics for precision MDR-TB diagnosis.

Prevalence of pulmonary tuberculosis among prison inmates: A cross-sectional survey at the Correctional and Detention Facility of Abidjan, Côte d'Ivoire

Background

In Côte d’Ivoire, a TB prison program has been developed since 1999. This program includes offering TB screening to prisoners who show up with TB symptoms at the infirmary. Our objective was to estimate the prevalence of pulmonary TB among inmates at the Correctional and Detention Facility of Abidjan, the largest prison of Côte d’Ivoire, 16 years after this TB program was implemented.

Methods

Between March and September 2015, inmates, were screened for pulmonary TB using systematic direct smear microscopy, culture and chest X-ray. All participants were also proposed HIV testing. TB was defined as either confirmed (positive culture), probable (positive microscopy and/or chest X-ray findings suggestive of TB) or possible (signs or symptoms suggestive of TB, no X-Ray or microbiological evidence). Factors associated with confirmed tuberculosis were analysed using multivariable logistic regression.

Results

Among the 943 inmates screened, 88 (9.3%) met the TB case definition, including 19 (2.0%) with confirmed TB, 40 (4.2%) with probable TB and 29 (3.1%) with possible TB. Of the 19 isolated TB strains, 10 (53%) were TB drug resistant, including 7 (37%) with multi-resistance. Of the 10 patients with TB resistant strain, only one had a past history of TB treatment. HIV prevalence was 3.1% overall, and 9.6%among TB cases. Factors associated with confirmed TB were age ≥30 years (Odds Ratio 3.8; 95% CI 1.1–13.3), prolonged cough (Odds Ratio 3.6; 95% CI 1.3–9.5) and fever (Odds Ratio 2.7; 95% CI 1.0–7.5).

Conclusion

In the country largest prison, pulmonary TB is still 10 (confirmed) to 44 times (confirmed, probable or possible) as frequent as in the Côte d’Ivoire general population, despite a long-time running symptom-based program of TB detection. Decreasing TB prevalence and limiting the risk of MDR may require the implementation of annual in-cell TB screening campaigns that systematically target all prison inmates.

Cost-effectiveness of active case-finding of household contacts of pulmonary tuberculosis patients in a low HIV, tuberculosis-endemic urban area of Lima, Peru

We compared the cost-effectiveness (CE) of an active case-finding (ACF) programme for household contacts of tuberculosis (TB) cases enrolled in first-line treatment to routine passive case-finding (PCF) within an established national TB programme in Peru. Decision analysis was used to model detection of TB in household contacts through: (1) self-report of symptomatic cases for evaluation (PCF), (2) a provider-initiated ACF programme, (3) addition of an Xpert MTB/RIF diagnostic test for a single sputum sample from household contacts, and (4) all strategies combined. CE was calculated as the incremental cost-effectiveness ratio (ICER) in terms of US dollars per disability-adjusted life years (DALYs) averted. Compared to PCF alone, ACF for household contacts resulted in an ICER of $2155 per DALY averted. The addition of the Xpert MTB/RIF diagnostic test resulted in an ICER of $3275 per DALY averted within a PCF programme and $3399 per DALY averted when an ACF programme was included. Provider-initiated ACF of household contacts in an urban setting of Lima, Peru can be highly cost-effective, even including costs to seek out contacts and perform an Xpert/MTB RIF test. ACF including Xpert MTB/RIF was not cost-effective if TB cases detected had high rates of default from treatment or poor outcomes.

Investments in tuberculosis research - what are the gaps?

Through decades of research, numerous studies have generated robust evidence about effective interventions for tuberculosis control. Yet, the global annual decline in incidence of approximately 1 % is evidence that current approaches and investment strategies are not sufficient. In this article, we assess recent tuberculosis research funding and discuss two critical gaps in funding and in scientific evidence from topics that have been left off the research priority agenda.We first examine research and development funding goals in the 2011-2015 Global Plan to Stop Tuberculosis and analyze disbursements to different research areas by funders worldwide in 2014. We then summarize, through a compilation of published literature and consultation with 35 researchers across multiple disciplines in the London School of Hygiene and Tropical Medicine TB Centre, priorities identified by the tuberculosis research community. Finally, we compare researchers' priority areas to the global funding agendas and activities.Our analysis shows that, among the five key research areas defined in the 2011-2015 Global Plan - namely drugs, basic science, vaccines, diagnostics and operational research - drug discovery and basic science on Mycobacterium tuberculosis accounted for 60 % of the $2 billion annual funding target. None of the research areas received the recommended level of funding. Operational research, which had the lowest target, received 66 % of its target funding, whereas new diagnostics received only 19 %. Although many of the priority research questions identified by researchers fell within the Global Plan categories, our analysis highlights important areas that are not explicitly mentioned in the current plan. These priority research areas included improved understanding of tuberculosis transmission dynamics, the role of social protection and social determinants, and health systems and policy research.While research priorities are increasingly important in light of the limited funding for tuberculosis, there is a risk that we neglect important research areas and encourage the formation of research silos. To ensure that funding priorities, researchers' agendas and national tuberculosis control policies are better coordinated, there should be more, and wider, dialogue between stakeholders in high tuberculosis burden countries, researchers, international policymakers and funders.

S100A12 is up-regulated in pulmonary tuberculosis and predicts the extent of alveolar infiltration on chest radiography: an observational study

Pulmonary tuberculosis (PTB) results in lung functional impairment and there are no surrogate markers to monitor the extent of lung involvement. We investigated the clinical significance of S100A12 and soluble receptor for advanced glycation end-products (sRAGE) for predicting the extent of lung involvement. We performed an observational study in India with 119 newly diagnosed, treatment naïve, sputum smear positive, HIV-negative PTB patients and 163 healthy controls. All patients were followed-up for six months. Sociodemographic variables and the serum levels of S100A12, sRAGE, esRAGE, HMGB-1, TNF-α, IFN-γ and CRP were measured. Lung involvement in PTB patients was assessed by chest radiography. Compared with healthy controls, PTB patients had increased serum concentrations of S100A12 while sRAGE was decreased. S100A12 was an independent predictor of disease occurrence (OR 1.873, 95%CI 1.212-2.891, p = 0.004). Under DOTS therapy, S100A12 decreased significantly after 4 months whereas CRP significantly decreased after 2 months (p < 0.0001). Importantly, although CRP was also an independent predictor of disease occurrence, only S100A12 was a significant predictor of lung alveolar infiltration (OR 2.60, 95%CI 1.35-5.00, p = 0.004). These results suggest that S100A12 has the potential to assess the extent of alveolar infiltration in PTB.

The global tuberculosis situation and the inexorable rise of drug-resistant disease

The highly cost-effective DOTS strategy helped to bring the global tuberculosis (TB) epidemic under control in many parts of the world; however, the emergence and spread of drug-resistant strains pose a major threat to these gains. Molecular epidemiology studies, together with recent genomic evidence, provide proof that some drug-resistant strains are highly transmissible with documented epidemic spread. The potential for epidemic replacement of drug-susceptible with drug-resistant strains provides strong motivation for renewed emphasis on TB drug and vaccine development. It also reflects the need for enhanced infection control measures in health care and congregate settings, especially in TB endemic areas. The exploration of preventive therapy options for close contacts of patients with infectious drug-resistant TB also warrants further exploration, in an attempt to break the transmission cycle. Increased population mobility and large scale cross-border migration imply that the inexorable rise of drug-resistant TB is not geographically confined; it is a global concern that poses a very real threat to TB endemic and non-endemic settings. Failure to find new solutions will compromise traditional TB control efforts and derail momentum toward future TB elimination.

Programmatic Management of Drug-Resistant Tuberculosis: An Updated Research Agenda

Introduction

There are numerous challenges in delivering appropriate treatment for multidrug-resistant tuberculosis (MDR-TB) and the evidence base to guide those practices remains limited. We present the third updated Research Agenda for the programmatic management of drug-resistant TB (PMDT), assembled through a literature review and survey.

Methods

Publications citing the 2008 research agenda and normative documents were reviewed for evidence gaps. Gaps were formulated into questions and grouped as in the 2008 research agenda: Laboratory Support, Treatment Strategy, Programmatically Relevant Research, Epidemiology, and Management of Contacts. A survey was distributed through snowball sampling to identify research priorities. Respondent priority rankings were scored and summarized by mean. Sensitivity analyses explored weighting and handling of missing rankings.

Results

Thirty normative documents and publications were reviewed for stated research needs; these were collapsed into 56 research questions across 5 categories. Of more than 500 survey recipients, 133 ranked priorities within at least one category. Priorities within categories included new diagnostics and their effect on improving treatment outcomes, improved diagnosis of paucibacillary and extra pulmonary TB, and development of shorter, effective regimens. Interruption of nosocomial transmission and treatment for latent TB infection in contacts of known MDR−TB patients were also top priorities in their respective categories. Results were internally consistent and robust.

Discussion

Priorities retained from the 2008 research agenda include shorter MDR-TB regimens and averting transmission. Limitations of recent advances were implied in the continued quest for: shorter regimens containing new drugs, rapid diagnostics that improve treatment outcomes, and improved methods of estimating burden without representative data.

Conclusion

There is continuity around the priorities for research in PMDT. Coordinated efforts to address questions regarding shorter treatment regimens, knowledge of disease burden without representative data, and treatment for LTBI in contacts of known DR-TB patients are essential to stem the epidemic of TB, including DR-TB.

High Sequence Variability of the ppE18 Gene of Clinical Mycobacterium tuberculosis Complex Strains Potentially Impacts Effectivity of Vaccine Candidate M72/AS01E

The development of an effective vaccine is urgently needed to fight tuberculosis (TB) which is still the leading cause of death from a single infectious agent worldwide. One of the promising vaccine candidates M72/AS01E consists of two proteins subunits PepA and PPE18 coded by Rv0125 and Rv1196. However, preliminary data indicate a high level of sequence variability among clinical Mycobacterium tuberculosis complex (MTBC) strains that might have an impact on the vaccine efficacy. To further investigate this finding, we determined ppE18 sequence variability in a well-characterized reference collection of 71 MTBC strains from 23 phylogenetic lineages representing the global MTBC diversity. In total, 100 sequence variations consisting of 96 single nucleotide polymorphisms (SNPs), three insertions and one deletion were detected resulting in 141 variable positions distributed over the entire gene. The majority of SNPs detected were non-synonymous (n = 68 vs. n = 28 synonymous). Strains from animal adapted lineages, e.g., M. bovis, showed a significant higher diversity than the human pathogens such as M. tuberculosis Haarlem. SNP patterns specific for different lineages as well as for deeper branches in the phylogeny could be identified. The results of our study demonstrate a high variability of the ppE18 gene even in the N-terminal domains that is normally highly conserved in ppe genes. As the N-terminal region interacts with TLR2 receptor inducing a protective anti-inflammatory immune response, genetic heterogeneity has a potential impact on the vaccine efficiency, however, this has to be investigated in future studies.

Taking forward the World TB Day 2016 theme 'Unite to End Tuberculosis' for the WHO Africa Region

•

Tuberculosis (TB) has remained a global emergency ever since it was declared as such by the World Health Organization (WHO) in 1993.

•

Of the 9.6 million people who developed TB in 2014, 28% were in the WHO Africa Region, where the case rate was 281 per 100 000 population.

•

An estimated 1.2 million (12%) TB cases were HIV-positive and the Africa Region accounted for 74% of these cases.

•

The global spread of multidrug-resistant TB (MDR-TB) is now a major public health challenge.

•

Scientific, political, and funder communities seriously need to ‘Unite to End TB’, the theme of the 2016 World TB Day.

•

TB control programs in Africa can only succeed if mechanisms for close engagement of developing country scientists, healthcare workers, patient groups, governments, and policy-makers are ensured by funding and donor agencies.

•

Several funder, political, and community initiatives provide hope for achieving the goals of the WHO post-2015 TB strategy.

•

TB activities and funder investments in Africa need to be aligned in parallel with international efforts at improving social and living conditions and with the ‘one health’ initiative.

Tuberculosis (TB) remains a global emergency, with an estimated 9.6 million new TB cases worldwide reported in 2014. Twenty-eight percent of these cases were in the World Health Organization (WHO) Africa Region, where the annual case detection rate was 281 per 100 000 population—more than double the global average of 133 per 100 000. Of the 9.6 million people who developed TB, an estimated 1.2 million (12%) were HIV-positive, and the Africa Region accounted for 74% of these cases. Three million people with TB remain undiagnosed and untreated. Globally, an estimated 480 000 had multidrug-resistant TB (MDR-TB). Whilst of the African countries, only South Africa has reported a high prevalence of MDR-TB, it is likely that all of Sub-Saharan Africa has an unreported high load of drug-resistant TB. Tragically, in 2014, only 48% of individuals diagnosed with MDR-TB had successful treatment and an estimated 190 000 people died of MDR-TB. Of the global TB funding gap of US$ 0.8 billion, the largest funding gap was in the Africa Region, amounting to US$ 0.4 billion in 2015. The MDR-TB pandemic in particular now threatens to devastate entire regions and may fundamentally alter the life-expectancy and demographic profile of many countries in Sub-Saharan Africa. The theme designated for this year's World TB Day, March 24, 2016, is ‘Unite to End TB’. From the Africa Region, there is an urgent need to seriously address the political, economic, and social factors that influence host–Mycobacterium tuberculosis interactions and result in disease. Recent political and funder initiatives that provide renewed hope for the alleviation of Africa's TB and TB/HIV problems are discussed.

Setting priorities for a research agenda to combat drug-resistant tuberculosis in children

SETTING

Numerous knowledge gaps hamper the prevention and treatment of childhood drug-resistant tuberculosis (TB). Identifying research priorities is vital to inform and develop strategies to address this neglected problem.

OBJECTIVE

To systematically identify and rank research priorities in childhood drug-resistant TB.

DESIGN

Adapting the Child Health and Nutrition Research Initiative (CHNRI) methodology, we compiled 53 research questions in four research areas, then classified the questions into three research types. We invited experts in childhood drug-resistant TB to score these questions through an online survey.

RESULTS

A total of 81 respondents participated in the survey. The top-ranked research question was to identify the best combination of existing diagnostic tools for early diagnosis. Highly ranked treatment-related questions centred on the reasons for and interventions to improve treatment outcomes, adverse effects of drugs and optimal treatment duration. The prevalence of drug-resistant TB was the highest-ranked question in the epidemiology area. The development type questions that ranked highest focused on interventions for optimal diagnosis, treatment and modalities for treatment delivery.

CONCLUSION

This is the first effort to identify and rank research priorities for childhood drug-resistant TB. The result is a resource to guide research to improve prevention and treatment of drug-resistant TB in children.

Cefsulodin Inspired Potent and Selective Inhibitors of mPTPB, a Virulent Phosphatase from Mycobacterium tuberculosis

mPTPB is a virulent phosphatase from Mycobacterium tuberculosis and a promising therapeutic target for tuberculosis. To facilitate mPTPB-based drug discovery, we identified α-sulfophenylacetic amide (SPAA) from cefsulodin, a third generation β-lactam cephalosporin antibiotic, as a novel pTyr pharmacophore for mPTPB. Structure-guided and fragment-based optimization of SPAA led to the most potent and selective mPTPB inhibitor 9, with a K i of 7.9 nM and more than 10,000-fold preference for mPTPB over a large panel of 25 phosphatases. Compound 9 also exhibited excellent cellular activity and specificity in blocking mPTPB function in macrophage. Given its novel structure, modest molecular mass, and extremely high ligand efficiency (0.46), compound 9 represents an outstanding lead compound for anti-TB drug discovery targeting mPTPB.

Global Tuberculosis Control: Toward the 2015 Targets and Beyond

Since 1990, progress has been made toward global tuberculosis (TB) control, as measured by targets set for 2015. However, TB remains a major threat to health around the world. In 2013, there were an estimated 11 million prevalent cases, and an estimated 9.0 million incident cases occurred globally. Approximately 1.5 million deaths were caused by TB, including 360,000 among people living with HIV. Substantial challenges threaten future control efforts. These include multidrug-resistant forms and co-infection with HIV, as well as other factors, such as the increased prominence of noncommunicable diseases and adverse socioeconomic conditions. Beyond 2015, TB control must be seen as both a public health imperative unto itself and a vital component of economic development plans. To that end, control strategies should exploit technical and operational innovations to improve TB control and care and should promote universal health coverage and social protection mechanisms to expand access to essential prevention, diagnostics, and treatment services while avoiding catastrophic costs incurred by patients.

Silico-tuberculosis and associated risk factors in central province of Iran

INTRODUCTION

Co-existence of silicosis and tuberculosis is known as silico-tuberculosis. This article review the frequency of silicosis and tuberculosis in workers who exposed to silica and evaluate influencing factors that may increase the risk of silico-tuberculosis.

METHODS

An analytical cross-sectional study was performed in silica exposed workers in central province of Iran during 2011-2012. Sampling method was un-randomized and considering all workers who at least 6 months exposed to silica. The study was done via questionnaire, clinical examination, spirometry, chest x-ray and tuberculosis investigations.

RESULTS

A total of 3,121 workers were included in the study, the mean age of participants was 43.1±12.4 years, and mean employment duration 14.9±6.8 years. Prevalence of TB in silica-exposed workers without silicosis was 172 cases per 100 000 people and prevalence in silicosis cases was 917 cases per 100 000 people. Incidence of TB in silica-exposed workers without silicosis was 69 cases per 100,000 people and incidence in silicosis cases was 459 cases per 100,000 people. The frequency of LTBI/TB was higher in age over thirty years old (P=0.02), in workers with employment duration over 10 years (P=0.004), in workers with exposure duration over 5 years (P=0.03) and smokers with over 5 pack-years (P=0.01).

CONCLUSION

Exposure to silica causes a renewed multiplication of bacilli in the healing TB lesions. Prevalence of pulmonary tuberculosis in Silicosis is more common when compared to prevalence in general population, hence all should use prophylactic measures Intensification of work place.

An overview of tuberculosis plant-derived vaccines

Tuberculosis (TB) is a leading fatal infectious disease to which the current BCG vaccine has a questionable efficacy in adults. Thus, the development of improved vaccines against TB is needed. In addition, decreasing the cost of vaccine formulations is required for broader vaccination coverage through global vaccination programs. In this regard, the use of plants as biofactories and delivery vehicles of TB vaccines has been researched over the last decade. These studies are systematically analyzed in the present review and placed in perspective. It is considered that substantial preclinical trials are still required to address improvements in expression levels as well as immunological data. Approaches for testing additional antigenic configurations with higher yields and improved immunogenic properties are also discussed.

Decline in overall, smear-negative and HIV-positive TB incidence while smear-positive incidence stays stable in Guinea-Bissau 2004-2011

OBJECTIVE

To calculate Tuberculosis (TB) incidence rates in Guinea-Bissau over an 8-year period.

METHODS

Since 2003, a surveillance system has registered all TB cases in six suburban districts of Bissau. In this population-based prospective follow-up study, 1205 cases of pulmonary TB were identified between January 2004 and December 2011. Incidence rates were calculated using census data from the Bandim Health and Demographic Surveillance System (HDSS).

RESULTS

The overall incidence of pulmonary TB was 279 per 100,000 person-years of observation; the male incidence being 385, and the female 191. TB incidence rates increased significantly with age in both sexes, regardless of smear or HIV status. Despite a peak with unknown cause of 352 per 100,000 in 2007, the overall incidence of pulmonary TB declined over the period. The incidence of HIV infected TB cases declined significantly from 108 to 39 per 100,000, while the incidence of smear-positive TB cases remained stable; the overall figure was 188 per 100,000.

CONCLUSIONS

Overall incidence of pulmonary TB in Guinea-Bissau has declined from 2004 to 2011. The decline was also seen in the subgroups of smear-negative and HIV-positive TB cases, probably due to antiretroviral treatment. Smear-positive TB incidence remains stable over the period.

Political commitment to tuberculosis control in Ghana

As part of expanding and sustaining tuberculosis (TB) control, the Stop TB Partnership of the World Health Organization initiative has called for strong political commitment to TB control, particularly in developing countries. Framing political commitment within the theoretical imperatives of the political economy of health, this study explores the existing and the expected dimensions of political commitment to TB control in Ghana. Semi-structured in-depth interviews were conducted with 29 purposively selected staff members of the Ghana Health Service and some political officeholders. In addition, the study analysed laws, policies and regulations relevant to TB control. Four dimensions of political commitment emerged from the interviews: provision of adequate resources (financial, human and infrastructural); political authorities' participation in advocacy for TB; laws and policies' promulgation and social protection interventions. Particularly in respect to financial resources, donors such as the Global Fund to Fight AIDS, Tuberculosis and Malaria presently give more than 60% of the working budget of the programme. The documentary review showed that laws, policies and regulations existed that were relevant to TB control, albeit they were not clearly linked.

Reverse translation in tuberculosis: neutrophils provide clues for understanding development of active disease

Tuberculosis (TB) is a major health issue globally. Although typically the disease can be cured by chemotherapy in all age groups, and prevented in part in newborn by vaccination, general consensus exists that development of novel intervention measures requires better understanding of disease mechanisms. Human TB is characterized by polarity between host resistance as seen in 2 billion individuals with latent TB infection and susceptibility occurring in 9 million individuals who develop active TB disease every year. Experimental animal models often do not reflect this polarity adequately, calling for a reverse translational approach. Gene expression profiling has allowed identification of biomarkers that discriminate between latent infection and active disease. Functional analysis of most relevant markers in experimental animal models can help to better understand mechanisms driving disease progression. We have embarked on in-depth characterization of candidate markers of pathology and protection hereby harnessing mouse mutants with defined gene deficiencies. Analysis of mutants deficient in miR-223 expression and CXCL5 production allowed elucidation of relevant pathogenic mechanisms. Intriguingly, these deficiencies were linked to aberrant neutrophil activities. Our findings point to a detrimental potential of neutrophils in TB. Reciprocally, measures that control neutrophils should be leveraged for amelioration of TB in adjunct to chemotherapy.

Potential impact of the US President's Emergency Plan for AIDS relief on the tuberculosis/HIV coepidemic in selected Sub-Saharan African countries

BACKGROUND

There are limited data measuring the impact of expanded human immunodeficiency virus (HIV) prevention activities on the tuberculosis epidemic at the country level. Here, we characterized the potential impact of the US President's Emergency Plan for AIDS Relief (PEPFAR) on the tuberculosis epidemic in sub-Saharan Africa.

METHODS

We selected 12 focus countries (countries receiving the greatest US government investments) and 29 nonfocus countries (controls). We used tuberculosis incidence and mortality rates and relative risks to compare time periods before and after PEPFAR's inception, and a tuberculosis/HIV indicator to calculate the rate of change in tuberculosis incidence relative to the HIV prevalence.

RESULTS

Comparing the periods before and after PEPFAR's implementation, both tuberculosis incidence and mortality rates have diminished significantly and to a higher degree in focus countries. The relative risk for developing tuberculosis, comparing those with and without HIV, was 22.5 for control and 20.0 for focus countries. In most focus countries, the tuberculosis epidemic is slowing down despite some regions still experiencing an increase in HIV prevalence.

CONCLUSIONS

This ecological study showed that PEPFAR had a more consistent and substantial effect on HIV and tuberculosis in focus countries, highlighting the likely link between high levels of HIV investment and broader effects on related diseases such as tuberculosis.

Spectrum of Disease in Children Treated for Tuberculosis at a Tertiary Children's Hospital in Australia

BACKGROUND

Tuberculosis (TB) notification rates in Australia have plateaued at a low level, but the pediatric disease burden remains poorly described. Child cases provide a marker of recent transmission and present unique diagnostic challenges.

METHODS

We performed an audit of all children (<18 years of age) treated for TB at the Children's Hospital at Westmead, Sydney, Australia from January 2008 to December 2011. Demographics, clinical presentation, diagnostics, disease profile, treatment, and outcome were reviewed.

RESULTS

A total of 25 children were treated for TB: 15 had microbiologically confirmed TB; 7 were diagnosed on clinical grounds; and in 3, an alternate diagnosis was established (2 bacille Calmette-Guérin disease and 1 atypical mycobacterial infection). Of the 22 TB cases, 21 had a history of immigration or travel to a TB-endemic country and 4 reported recent contact with a TB source case within Australia. Isolated intrathoracic TB was documented in 16 (72%) cases. Symptoms on presentation included the following: lethargy, weakness, or malaise (75%); fever (73%); and cough (64%). Among the 15 children with microbiologically confirmed TB, 11 (73%) were positive by culture and 11 of 13 (85%) by polymerase chain reaction test. Tuberculin skin test was positive (≥10 mm) in 80% (16 of 20) of cases, and interferon-gamma release assay was positive in 87% (13 of 15) of cases. All children received directly observed therapy and recovered.

CONCLUSIONS

This series demonstrates the broad spectrum of disease with which pediatric TB cases present and the need for ongoing vigilance. A more comprehensive review of pediatric TB cases throughout Australia would be informative.

Epidemiology and etiology of childhood pneumonia in 2010: estimates of incidence, severe morbidity, mortality, underlying risk factors and causative pathogens for 192 countries

Background

The recent series of reviews conducted within the Global Action Plan for Pneumonia and Diarrhoea (GAPPD) addressed epidemiology of the two deadly diseases at the global and regional level; it also estimated the effectiveness of interventions, barriers to achieving high coverage and the main implications for health policy. The aim of this paper is to provide the estimates of childhood pneumonia at the country level. This should allow national policy–makers and stakeholders to implement proposed policies in the World Health Organization (WHO) and UNICEF member countries.

Methods

We conducted a series of systematic reviews to update previous estimates of the global, regional and national burden of childhood pneumonia incidence, severe morbidity, mortality, risk factors and specific contributions of the most common pathogens: Streptococcus pneumoniae (SP), Haemophilus influenzae type B (Hib), respiratory syncytial virus (RSV) and influenza virus (flu). We distributed the global and regional–level estimates of the number of cases, severe cases and deaths from childhood pneumonia in 2010–2011 by specific countries using an epidemiological model. The model was based on the prevalence of the five main risk factors for childhood pneumonia within countries (malnutrition, low birth weight, non–exclusive breastfeeding in the first four months, solid fuel use and crowding) and risk effect sizes estimated using meta–analysis.

Findings

The incidence of community–acquired childhood pneumonia in low– and middle–income countries (LMIC) in the year 2010, using World Health Organization's definition, was about 0.22 (interquartile range (IQR) 0.11–0.51) episodes per child–year (e/cy), with 11.5% (IQR 8.0–33.0%) of cases progressing to severe episodes. This is a reduction of nearly 25% over the past decade, which is consistent with observed reductions in the prevalence of risk factors for pneumonia throughout LMIC. At the level of pneumonia incidence, RSV is the most common pathogen, present in about 29% of all episodes, followed by influenza (17%). The contribution of different pathogens varies by pneumonia severity strata, with viral etiologies becoming relatively less important and most deaths in 2010 caused by the main bacterial agents – SP (33%) and Hib (16%), accounting for vaccine use against these two pathogens.

Conclusions

In comparison to 2000, the primary epidemiological evidence contributing to the models of childhood pneumonia burden has improved only slightly; all estimates have wide uncertainty bounds. Still, there is evidence of a decreasing trend for all measures of the burden over the period 2000–2010. The estimates of pneumonia incidence, severe morbidity, mortality and etiology, although each derived from different and independent data, are internally consistent – lending credibility to the new set of estimates. Pneumonia continues to be the leading cause of both morbidity and mortality for young children beyond the neonatal period and requires ongoing strategies and progress to reduce the burden further.

Epidemic spread of multidrug-resistant tuberculosis in Johannesburg, South Africa

Numerous reports have documented isolated transmission events or clonal outbreaks of multidrug-resistant Mycobacterium tuberculosis strains, but knowledge of their epidemic spread remains limited. In this study, we evaluated drug resistance, strain diversity, and clustering rates in patients diagnosed with multidrug-resistant (MDR) tuberculosis (TB) at the National Health Laboratory Service (NHLS) Central TB Laboratory in Johannesburg, South Africa, between March 2004 and December 2007. Phenotypic drug susceptibility testing was done using the indirect proportion method, while each isolate was genotyped using a combination of spoligotyping and 12-MIRU typing (12-locus multiple interspersed repetitive unit typing). Isolates from 434 MDR-TB patients were evaluated, of which 238 (54.8%) were resistant to four first-line drugs (isoniazid, rifampin, ethambutol, and streptomycin). Spoligotyping identified 56 different strains and 28 clusters of variable size (2 to 71 cases per cluster) with a clustering rate of 87.1%. Ten clusters included 337 (77.6%) of all cases, with strains of the Beijing genotype being most prevalent (16.4%). Combined analysis of spoligotyping and 12-MIRU typing increased the discriminatory power (Hunter Gaston discriminatory index [HGDI] = 0.962) and reduced the clustering rate to 66.8%. Resolution of Beijing genotype strains was further enhanced with the 24-MIRU-VNTR (variable-number tandem repeat) typing method by identifying 15 subclusters and 19 unique strains from twelve 12-MIRU clusters. High levels of clustering among a variety of strains suggest a true epidemic spread of MDR-TB in the study setting, emphasizing the urgency of early diagnosis and effective treatment to reduce transmission within this community.

Tuberculosis comorbidity with communicable and non-communicable diseases: integrating health services and control efforts

Recent data for the global burden of disease reflect major demographic and lifestyle changes, leading to a rise in non-communicable diseases. Most countries with high levels of tuberculosis face a large comorbidity burden from both non-communicable and communicable diseases. Traditional disease-specific approaches typically fail to recognise common features and potential synergies in integration of care, management, and control of non-communicable and communicable diseases. In resource-limited countries, the need to tackle a broader range of overlapping comorbid diseases is growing. Tuberculosis and HIV/AIDS persist as global emergencies. The lethal interaction between tuberculosis and HIV coinfection in adults, children, and pregnant women in sub-Saharan Africa exemplifies the need for well integrated approaches to disease management and control. Furthermore, links between diabetes mellitus, smoking, alcoholism, chronic lung diseases, cancer, immunosuppressive treatment, malnutrition, and tuberculosis are well recognised. Here, we focus on interactions, synergies, and challenges of integration of tuberculosis care with management strategies for non-communicable and communicable diseases without eroding the functionality of existing national programmes for tuberculosis. The need for sustained and increased funding for these initiatives is greater than ever and requires increased political and funder commitment.