Tuberculosis

Does the Development of Vaccines Advance Solutions for Tuberculosis?

BACKGROUND

Mycobacterium tuberculosis (Mtb) is considered as one of the most efficacious human pathogens. The global mortality rate of TB stands at approximately 2 million, while about 8 to 10 million active new cases are documented yearly. It is, therefore, a priority to develop vaccines that will prevent active TB. The vaccines currently used for the management of TB can only proffer a certain level of protection against meningitis, TB, and other forms of disseminated TB in children; however, their effectiveness against pulmonary TB varies and cannot provide life-long protective immunity. Based on these reasons, more efforts are channeled towards the development of new TB vaccines. During the development of TB vaccines, a major challenge has always been the lack of diversity in both the antigens contained in TB vaccines and the immune responses of the TB sufferers. Current efforts are channeled on widening both the range of antigens selection and the range of immune response elicited by the vaccines. The past two decades witnessed a significant progress in the development of TB vaccines; some of the discovered TB vaccines have recently even completed the third phase (phase III) of a clinical trial.

OBJECTIVE

The objectives of this article are to discuss the recent progress in the development of new vaccines against TB; to provide an insight on the mechanism of vaccine-mediated specific immune response stimulation, and to debate on the interaction between vaccines and global interventions to end TB.

A rapid and sensitive system for recovery of nucleic acids from Mycobacteria sp. on archived glass slides

BACKGROUND

The field of diagnostics continues to advance rapidly with a variety of novel approaches, mainly dependent upon high technology platforms. Nonetheless much diagnosis, particularly in developing countries, still relies upon traditional methods such as microscopy. Biological material, particularly nucleic acids, on archived glass slides is a potential source of useful information both for diagnostic and epidemiological purposes. There are significant challenges faced when examining archived samples in order that an adequate amount of amplifiable DNA can be obtained. Herein, we describe a model system to detect low numbers of bacterial cells isolated from glass slides using (laser capture microscopy) LCM coupled with PCR amplification of a suitable target.

RESULTS

Mycobacterium smegmatis was used as a model organism to provide a proof of principle for a method to recover bacteria from a stained sample on a glass slide using a laser capture system. Ziehl-Neelsen (ZN) stained cells were excised and catapulted into tubes. Recovered cells were subjected to DNA extraction and pre-amplified with multiple displacement amplification (MDA). This system allowed a minimum of 30 catapulted cells to be detected following a nested real-time PCR assay, using rpoB specific primers. The combination of MDA and nested real-time PCR resulted in a 30-fold increase in sensitivity for the detection of low numbers of cells isolated using LCM.

CONCLUSIONS

This study highlights the potential of LCM coupled with MDA as a tool to improve the recovery of amplifiable nucleic acids from archived glass slides. The inclusion of the MDA step was essential to enable downstream amplification. This platform should be broadly applicable to a variety of diagnostic applications and we have used it as a proof of principle with a Mycobacterium sp. model system.

Significance of a histone-like protein with its native structure for the diagnosis of asymptomatic tuberculosis

Tuberculosis causes the highest mortality among all single infections. Asymptomatic tuberculosis, afflicting one third of the global human population, is the major source as 5–10% of asymptomatic cases develop active tuberculosis during their lifetime. Thus it is one of important issues to develop diagnostic tools for accurately detecting asymptomatic infection. Mycobacterial DNA-binding protein 1 (MDP1) is a major protein in persistent Mycobacterium tuberculosis and has potential for diagnostic use in detecting asymptomatic infection. However, a previous ELISA-based study revealed a specificity problem; IgGs against MDP1 were detected in both M. tuberculosis-infected and uninfected individuals. Although the tertiary structures of an antigen are known to influence antibody recognition, the MDP1 structural details have not yet been investigated. The N-terminal half of MDP1, homologous to bacterial histone-like protein HU, is predicted to be responsible for DNA-binding, while the C-terminal half is assumed as totally intrinsically disordered regions. To clarify the relationship between the MDP1 tertiary structure and IgG recognition, we refined the purification method, which allow us to obtain a recombinant protein with the predicted structure. Furthermore, we showed that an IgG-ELISA using MDP1 purified by our refined method is indeed useful in the detection of asymptomatic tuberculosis.

Label-Free and Real-Time Detection of Tuberculosis in Human Urine Samples Using a Nanophotonic Point-of-Care Platform

Tuberculosis (TB) is the leading global cause of death from a single infectious agent. Registered incidence rates are low, especially in low-resource countries with weak health systems, due to the disadvantages of current diagnostic techniques. A major effort is directed to develop a point-of-care (POC) platform to reduce TB deaths with a prompt and reliable low-cost technique. In the frame of the European POCKET Project, a novel POC platform for the direct and noninvasive detection of TB in human urine was developed. The photonic sensor chip is integrated in a disposable cartridge and is based on a highly sensitive Mach-Zehnder Interferometer (MZI) transducer combined with an on-chip spectral filter. The required elements for the readout are integrated in an instrument prototype, which allows real-time monitoring and data processing. In this work, the novel POC platform has been employed for the direct detection of lipoarabinomannan (LAM), a lipopolysaccharide found in the mycobacterium cell wall. After the optimization of several parameters, a limit of detection of 475 pg/mL (27.14 pM) was achieved using a direct immunoassay in undiluted human urine in less than 15 min. A final validation of the technique was performed using 20 clinical samples from TB patients and healthy donors, allowing the detection of TB in people regardless of HIV coinfection. The results show excellent correlation to those obtained with standard techniques. These promising results demonstrate the high sensitivity, specificity and applicability of our novel POC platform, which could be used during routine check-ups in developing countries.

Comparative Evaluation of QuantiFERON-TB Gold In-Tube and QuantiFERON-TB Gold Plus in Diagnosis of Latent Tuberculosis Infection in Immunocompromised Patients

QuantiFERON-TB Gold Plus (QFT-Plus) is a new-generation QuantiFERON-TB Gold In-Tube (QFT-GIT) assay which has two antigen-coated tubes called TB1, which contains long peptides derived from ESAT-6 and CFP-10, and TB2, which contains the same components as TB1 and additional short peptides which potentially stimulate CD8⁺ T cells through the presentation of major histocompatibility complex class I. This is the first study to compare QFT-Plus and QFT-GIT for use in the diagnosis of latent tuberculosis infection (LTBI) among immunocompromised patients in the Republic of Korea. Among 317 consecutive patients who underwent screening for LTBI before solid organ or hematopoietic stem cell transplantation and tumor necrosis factor alpha inhibitor treatment, LTBI was identified in 92 (29.0%) and 88 (27.8%) patients by QFT-GIT and QFT-Plus, respectively. The rate of concordance between QFT-GIT and QFT-Plus was 93.7% (κ value, 0.860), and the indeterminate rate (3.2%) was similar between QFT-GIT and QFT-Plus. Of 20 (6.3%) samples with discordant results, 11 (55.0%) and 7 (35.0%) were positive by QFT-GIT alone and QFT-Plus alone, respectively, and 2 (15.0%) were indeterminate by each assay. The interferon gamma level in samples with discordant results ranged from 0.39 to 1.10 IU/ml, except for one sample, in which the gamma interferon level was 2.97 IU/ml only in TB2. Conclusively, there was a high degree of agreement between the results of QFT-GIT and QFT-Plus for the screening of immunocompromised patients for LTBI. The reactivity in TB2 contributed substantially to the difference between QFT-GIT and QFT-Plus, particularly in solid organ transplant candidates. The significance of the discrete responses in TB1 and TB2 of QFT-Plus needs to be explored further by means of an immunological and clinical approach in different patient groups and clinical settings.

Does the use of adjunct urine lipopolysaccharide lipoarabinomannan in HIV-infected hospitalized patients reduce the utilization of healthcare resources? A post hoc analysis of the LAM multi-country randomized controlled trial

BACKGROUND

The World Health Organization (WHO) recommends the use of adjunctive urine lipopolysaccharide lipoarabinomannan (LAM) testing in hospitalized HIV-infected persons with suspected tuberculosis (TB) and a CD4 count <100cells/ml. However, the recommendation is conditional, and uptake by individual treatment programmes depends on perceived additional benefit. The aim of this study was to determine whether adjunctive LAM testing has additional clinical benefits including a reduction in healthcare-related use of resources.

METHODS

A post hoc analysis was performed of a published multicentre, multi-country, randomized controlled trial that showed an approximate 20% mortality benefit in HIV-infected hospitalized patients who underwent adjunctive LAM testing as part of their diagnostic workup. In that parent study, adult HIV-infected hospitalized patients with suspected TB (n=2528) were randomly allocated to either routine diagnostics (smear microscopy, Xpert MTB/RIF, and culture; n=1271), or routine diagnostics plus adjunctive urine LAM testing (n=1257). Data were further analyzed to determine whether there were other potential benefits of LAM usage based on CD4 count and illness severity. Aspects evaluated included: (1) the reduction in number of diagnostic sputum samples tested, (2) the utilization of additional imaging, (3) disease resolution based on follow-up signs and symptoms of illness severity, and (4) the reduction in hospital readmission.

RESULTS

Adjuvant LAM did not reduce the number of diagnostic sputum samples requested, the need for additional imaging, or the hospital readmission rate. However, adjunctive LAM was associated with a more rapid rate of disease resolution (dyspnoea) in the severely ill subgroup. Higher LAM grade (grades 4 and 5), compared to lower grade positivity (≤3), was associated with lower use of ultrasound, lower Karnofsky performance score, lower CD4 cell count, and shorter time to culture positivity.

CONCLUSIONS

Although, adjunct LAM was associated with a mortality benefit in the parent study, no benefit could be demonstrated in the secondary analysis with respect to the number of diagnostic sputum samples requested, the use of additional imaging, or hospital readmission rates. However, given the limitations of the present study, further appropriately designed studies are required to determine the effect of adjunct urine LAM on the utilization of healthcare resources.

C-Tb skin test to diagnose Mycobacterium tuberculosis infection in children and HIV-infected adults: A phase 3 trial

Background

C-Tb, an ESAT-6/CFP-10-based skin test, has similar sensitivity for active TB compared to tuberculin skin test (TST) and QuantiFERON-TB-Gold-In-Tube (QFT). However, data are limited in children and HIV-infected persons.

Methods

Asymptomatic South African contacts <5 years (n = 87; HIV-uninfected), or symptomatic individuals of all ages presenting to clinics with suspected TB (n = 1003; 30% HIV-infected) were recruited from eight South African centres. C-Tb and TST were allocated to either forearm double blinded. Samples for QFT were collected in parallel, and test-positivity rates were compared.

Results

In participants with microbiologically confirmed TB (n = 75; 45% HIV-infected) sensitivity of C-Tb, TST and QFT were similar (72% versus 75% versus 73%; p>0.5). All 3 tests had similar positivity rates in HIV-infected participants with active TB, however, positivity rates were reduced when CD4 counts were <100 cells/μL. In participants where active TB was excluded (n = 920), C-Tb (41%), TST (43%), and QFT (44%) also had similar test-positivity rates. Among asymptomatic contacts aged below five, 32% (28/87) tested positive with C-Tb and 32% (28/87) with TST (concordance 89%). Overall, C-Tb and TST showed a similar safety profile.

Conclusion

C-Tb was safe and showed similar test-positivity rates, compared to TST and QFT, in children and HIV-infected persons with active or latent M. tuberculosis infection. These data inform the utility of C-Tb in clinical practice.

Trial registration

ClinicalTrials.gov NCT01642888.

EudraCT 2011-005078-40.

Risk factors for multidrug-resistant tuberculosis among tuberculosis patients in Serbia: a case-control study

BACKGROUND

Multidrug resistant (MDR) tuberculosis (TB) represents TB which is simultaneous resistant to at least rifampicin (R) and isoniazid (H). Identifying inadequate therapy as the main cause of this form of the disease and explaining the factors leading to its occurrence, numerous social determinants that affect the risk of developing resistance are highlighted. The objectives of the study was to identify independent factors of MDR-TB among tuberculosis patients.

METHODS

Case-control study was conducted from 1st September 2009 to 1st June 2014 in 31 healthcare institutions in Serbia where MDR-TB and TB patients were treated. TB patients infected with MDR- M. tuberculosis and non MDR- M. tuberculosis strain were considered as cases and controls, respectively. Cases and controls were matched by the date of hospitalization. The data was collected using structured questionnaire with face to face interview. Bivariate and multivariable logistic regression analysis (MLRA) were used to identify determinants associated with MDR-TB.

RESULTS

A total of 124 respondents, 31 cases and 93 controls were participated in the study. MLRA identified six significant independent risk factors for the occurrence of MDR-TB as follows: monthly income of the family (Odds ratio (OR) = 3.71; 95% Confidence Interval (CI) = 1.22-11.28), defaulting from treatment (OR = 3.33; 95% CI = 1.14-9.09), stigma associated with TB (OR = 2.97; 95% CI = 1.18-7.45), subjective feeling of sadness (OR = 4.05; 95% CI = 1.69-9.70), use of sedatives (OR = 2.79; 95% CI = 1.02-7.65) and chronic obstructive pulmonary disease (OR = 4.51; 95% CI = 1.07-18.96).

CONCLUSION

In order to reduce burden of drug resistance, strategies of controlling MDR-TB in Serbia should emphasize multi-sectorial actions, addressing health care and social needs of TB patients.

Plasma Circular RNAs hsa_circ_0001953 and hsa_circ_0009024 as Diagnostic Biomarkers for Active Tuberculosis

Recent studies have demonstrated that circular RNAs (circRNAs) could serve as potential molecular markers for disease diagnosis; however, little is known about their diagnostic value in active tuberculosis (TB). This study first performed a microarray screening of circRNA changes in plasma samples from 3 patients with active pulmonary TB and 3 healthy controls. Then, candidate circRNAs were selected for validation on a quantitative real-time PCR system. Of the 61 differentially expressed circRNAs recorded, 43 and 18 were upregulated and downregulated in the TB group, respectively. Validation assays demonstrated that plasma levels of 6 circRNAs, including hsa_circ_0009024, hsa_circ_0001953, hsa_circ_0008297, hsa_circ_0003528, hsa_circ_0003524 and hsa_circ_0015879 were remarkably increased in TB patients. Plasma levels of hsa_circ_0001953 and hsa_circ_0009024 were correlated with TB severity. Next, hsa_circ_0001953 and hsa_circ_0009024 were assessed in an independent cohort consisting of 120 TB patients and 100 control individuals. An area under the receiver operating characteristic (ROC) curve of 0.915 (95% confidence interval 0.880-0.951; P < 0.001) was obtained for detecting TB, with hsa_circ_0001953 and hsa_circ_0009024 used in combination. Additionally, plasma levels of hsa_circ_0001953 and hsa_circ_0009024 were reduced significantly in patients after treatment (P < 0.001). The present findings indicate that the circRNAs hsa_circ_0001953 and hsa_circ_0009024 may represent novel plasma biomarkers for active TB diagnosis.

Delayed diagnosis of extrapulmonary tuberculosis presenting as fever of unknown origin in an intermediate-burden country

Background

Tuberculosis (TB), especially extrapulmonary tuberculosis (EPTB), is an important cause of fever of unknown origin (FUO) in TB-burdened areas. Little information is known about patients with EPTB with clinical features presenting as FUO and about the factor of delaying the diagnosis.

Methods

We retrospectively analyzed EPTB patients who were referred with FUO at 3 university-affiliated hospitals over 8 years (2010–2017). The subjects were assigned to groups of early diagnosis and delayed diagnosis within 3 days of an initial comprehensive evaluation from the referral. Clinical and laboratory variables were compared between the groups.

Results

A total of 95 patients with febrile EPTB were included. Localizing symptoms and/or signs suggestive of anatomy were identified in 62.1% of the patients. Concurrent lung involvement by TB was presented by 49.5% (47/95) of the patients, and only 23.4% of them showed typical findings of pulmonary TB on simple chest X-ray. Most of the patients showed abnormal lesions on cross-sectional CT (98.9%) and MRI (100%). The clinical variables and blood test results of patients were not significantly different between the two groups. The less typical imaging finding of EPTB on CT (38.5% vs. 79.0%) and MRI (37.5% vs. 79.0%) in the delayed diagnosis group was a risk factor for delayed diagnosis.

Conclusion

Febrile EPTB referred as FUO showed nonspecific clinical manifestations. The active application of cross-sectional imaging tests according to clinical clues or randomly in the absence of local manifestations, combined with invasive diagnostic approaches even for atypical presentations may lead to an earlier diagnosis of febrile EPTB.

Epidemiological profile of tuberculosis in São Paulo municipality from 2006 to 2013

BACKGROUND

Tuberculosis is a serious public health problem that still persists in the world and in Brazil. The municipality of São Paulo, Brazil, is among the prioritized ones in the country for disease control.

OBJECTIVE

To describe the epidemiological profile of all new tuberculosis cases in São Paulo municipality reported between the years 2006 and 2013.

METHODS

The variables selected for the study were: socioeconomic, demographic and clinical-epidemiologic obtained through the online information system TB-WEB. A descriptive analysis of the data was performed to undertake the comparison among the years. To study the historical series, linear trend analysis was held.

RESULTS AND DISCUSSION

There was an increase in the tuberculosis incidence rate in children under 15 years and in homeless people. The cure rate has improved as the proportion of completion of supervised treatment and the proportion of cases diagnosed by primary care clinics. The disease is unevenly distributed within the municipality of São Paulo and there are districts that were not able to improve the tuberculosis control.

CONCLUSION

The municipal tuberculosis program control needs to target the vulnerable groups and the regions of the city where the incidence rates are higher.

Gut microbiota associated with pulmonary tuberculosis and dysbiosis caused by anti-tuberculosis drugs

BACKGROUND

An improved understanding of the gut microbiota could lead to better strategies for the diagnosis, therapy and prophylaxis of tuberculosis (TB). The impact of both Mycobacterium tuberculosis (Mtb) infection and anti-TB treatment on the gut microbiota has rarely been studied.

METHODS

We characterized the diversity and composition of the gut microbiota in pulmonary TB patients as well as the effects of anti-TB drugs on the gut microbiota.

RESULTS

Pulmonary Mtb infection led to a minor decrease in the α diversity of the gut microbiota when compared to healthy controls, which mainly resulted from changes in the relative abundance of the members of genus Bacteroides. Anti-TB therapy caused a rapid, significant alteration in the community structure. The relative abundance of members of genus Clostridiales of the phylum Firmicutes significantly decreased during anti-TB treatment, while many members of genus Bacteroides, including Bacteroides OTU230 and Bacteroides fragilis, were among the taxa that increased. OTU8 and OTU2972 assigned to family Erysipelotrichaceae of the phylum Firmicutes showed a dramatic increase 1 week after the start of therapy, while the other members of this family decreased.

CONCLUSIONS

Pulmonary TB and anti-TB treatment caused a distinct dysbiosis of the gut microbiota. Our study contributes valuable information implying potential links between the gut microbiota and TB.

Identification of Morpholino Thiophenes as Novel Mycobacterium tuberculosis Inhibitors, Targeting QcrB

With the emergence of multidrug-resistant strains of Mycobacterium tuberculosis there is a pressing need for new oral drugs with novel mechanisms of action. Herein, we describe the identification of a novel morpholino-thiophenes (MOT) series following phenotypic screening of the Eli Lilly corporate library against M. tuberculosis strain H37Rv. The design, synthesis, and structure-activity relationships of a range of analogues around the confirmed actives are described. Optimized leads with potent whole cell activity against H37Rv, no cytotoxicity flags, and in vivo efficacy in an acute murine model of infection are described. Mode-of-action studies suggest that the novel scaffold targets QcrB, a subunit of the menaquinol cytochrome c oxidoreductase, part of the bc1-aa3-type cytochrome c oxidase complex that is responsible for driving oxygen-dependent respiration.

Investigating the impact of TB case-detection strategies and the consequences of false positive diagnosis through mathematical modelling

Background

Increasing case notifications is one of the top programmatic priorities of National TB Control Programmes (NTPs). To find more cases, NTPs often need to consider expanding TB case-detection activities to populations with increasingly low prevalence of disease. Together with low-specificity diagnostic algorithms, these strategies can lead to an increasingly high number of false positive diagnoses, which has important adverse consequences.

Methods

We apply TIME, a widely-used country-level model, to quantify the expected impact of different case-finding strategies under two scenarios. In the first scenario, we compare the impact of implementing two different diagnostic algorithms (higher sensitivity only versus higher sensitivity and specificity) to reach programmatic screening targets. In the second scenario, we examine the impact of expanding coverage to a population with a lower prevalence of disease. Finally, we explore the implications of modelling without taking into consideration the screening of healthy individuals. Outcomes considered were changes in notifications, the ratio of additional false positive to true positive diagnoses, the positive predictive value (PPV), and incidence.

Results

In scenario 1, algorithm A of prolonged cough and GeneXpert yielded fewer additional notifications compared to algorithm B of any symptom and smear microscopy (n = 4.0 K vs 13.8 K), relative to baseline between 2017 and 2025. However, algorithm A resulted in an increase in PPV, averting 2.4 K false positive notifications thus resulting in a more efficient impact on incidence. Scenario 2 demonstrated an absolute decrease of 11% in the PPV as intensified case finding activities expanded into low-prevalence populations without improving diagnostic accuracy, yielding an additional 23 K false positive diagnoses for an additional 1.3 K true positive diagnoses between 2017 and 2025. Modelling the second scenario without taking into account screening amongst healthy individuals overestimated the impact on cases averted by a factor of 6.

Conclusion

Our findings show that total notifications can be a misleading indicator for TB programme performance, and should be interpreted carefully. When evaluating potential case-finding strategies, NTPs should consider the specificity of diagnostic algorithms and the risk of increasing false-positive diagnoses. Similarly, modelling the impact of case-finding strategies without taking into account potential adverse consequences can overestimate impact and lead to poor strategic decision-making.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3239-x) contains supplementary material, which is available to authorized users.

Incipient and Subclinical Tuberculosis: a Clinical Review of Early Stages and Progression of Infection

Tuberculosis (TB) is the leading infectious cause of mortality worldwide, due in part to a limited understanding of its clinical pathogenic spectrum of infection and disease. Historically, scientific research, diagnostic testing, and drug treatment have focused on addressing one of two disease states: latent TB infection or active TB disease. Recent research has clearly demonstrated that human TB infection, from latent infection to active disease, exists within a continuous spectrum of metabolic bacterial activity and antagonistic immunological responses. This revised understanding leads us to propose two additional clinical states: incipient and subclinical TB. The recognition of incipient and subclinical TB, which helps divide latent and active TB along the clinical disease spectrum, provides opportunities for the development of diagnostic and therapeutic interventions to prevent progression to active TB disease and transmission of TB bacilli. In this report, we review the current understanding of the pathogenesis, immunology, clinical epidemiology, diagnosis, treatment, and prevention of both incipient and subclinical TB, two emerging clinical states of an ancient bacterium.

Genome wide approaches discover novel Mycobacterium tuberculosis antigens as correlates of infection, disease, immunity and targets for vaccination

Every day approximately six thousand people die of Tuberculosis (TB). Its causative agent, Mycobacterium tuberculosis (Mtb), is an ancient pathogen that through its evolution developed complex mechanisms to evade immune surveillance and acquire the ability to establish persistent infection in its hosts. Currently, it is estimated that one-fourth of the human population is latently infected with Mtb and among those infected 3-10% are at risk of developing active TB disease during their lifetime. The currently available diagnostics are not able to detect this risk group for prophylactic treatment to prevent transmission. Anti-TB drugs are available but only as long regimens with considerable side effects, which could both be reduced if adequate tests were available to monitor the response of TB to treatment. New vaccines are also urgently needed to substitute or boost Bacille Calmette-Guérin (BCG), the only approved TB vaccine: although BCG prevents disseminated TB in infants, it fails to impact the incidence of pulmonary TB in adults, and therefore has little effect on TB transmission. To achieve TB eradication, the discovery of Mtb antigens that effectively correlate with the human response to infection, with the curative host response following TB treatment, and with natural as well as vaccine induced protection will be critical. Over the last decade, many new Mtb antigens have been found and proposed as TB biomarkers and vaccine candidates, but only a very small number of these is being used in commercial diagnostic tests or is being assessed as candidate TB vaccine antigens in human clinical trials, aiming to prevent infection, disease or disease recurrence following treatment. Most of these antigens were discovered decades ago, before the complete Mtb genome sequence became available, and thus did not harness the latest insights from post-genomic antigen discovery strategies and genome wide approaches. These have, for example, revealed critical phase variation in Mtb replication and accompanying gene -and therefore antigen- expression patterns. In this review, we present a brief overview of past methodologies, and subsequently focus on the most important recent Mtb antigen discovery studies which have mined the Mtb antigenome through "unbiased" genome wide approaches. We compare the results for these approaches -as far as we know for the first time-, highlight Mtb antigens that have been identified independently by different strategies and present a comprehensive overview of the Mtb antigens thus discovered.

Tuberculous Arthritis of the Ankle

Tuberculosis (TB) is an infectious disease caused by the Mycobacterium tuberculosis complex (MTBC). Pulmonary TB is the most common form of presentation, but extrapulmonary tuberculosis (EPTB) contributes significantly to morbidity and mortality. Rarely, patients with EPTB develop a form of ankle or foot arthritis. The diagnosis of TB arthritis is often overlooked because of the insidious onset and the non-specific clinical symptoms. Prognosis is generally poor; early diagnosis and delivery of the most appropriate treatment is critical to avoid functional disability.

Screening for Latent Tuberculosis Infection Among HIV-Infected Medicaid Enrollees

OBJECTIVES

In the United States, universal screening for latent tuberculosis (TB) infection among people with HIV is recommended, but the percentage receiving screening is unknown. This study assessed screening for latent TB infection among people with HIV enrolled in Medicaid during 2006-2010.

METHODS

We used nationwide fee-for-service Medicaid records to identify people with HIV, measure screening for latent TB infection, and examine associated demographic, social, and clinical factors. We used logistic regression analysis to calculate odds ratios (ORs) and 95% confidence intervals (CIs). We created 2 multivariate models to prevent collinearity between variables for length of HIV infection.

RESULTS

Of 152 831 people with HIV, 26 239 (17.2%) were screened for latent TB infection. The factor most strongly associated with screening was TB exposure or suspected TB (OR = 3.78; 95% CI, 3.27-4.37). Significant demographic characteristics associated with screening included being African American (OR = 1.28; 95% CI, 1.24-1.32) or ≤20 years of age (OR = 1.35; 95% CI, 1.28-1.42). Significant clinical and social factors associated with screening included poor housing conditions, low body mass index, chemotherapy treatment, and use of certain substances (ORs ranged from 1.24 [95% CI, 1.20-1.27] to 1.47 [95% CI, 1.22-1.76]). The screening rate for latent TB infection was higher among people with newly diagnosed HIV infection than among those with established infection (OR = 1.37; 95% CI, 1.32-1.41) and among people with a longer established HIV infection than among those with shorter HIV infection (OR = 1.24; 95% CI, 1.23-1.26 for each additional year).

CONCLUSION

Screening for latent TB infection among fee-for-service Medicaid beneficiaries with HIV was suboptimal, despite the presence of demographic, social, or clinical characteristics that should have increased the likelihood of screening. The lack of certain data in Medicaid may have resulted in an underestimation of screening.

Overview of the Development of DprE1 Inhibitors for Combating the Menace of Tuberculosis

Decaprenylphosphoryl-β-d-ribose 2'-epimerase (DprE1), a vital enzyme for cell wall synthesis, plays a crucial role in the formation of lipoarabinomannan and arabinogalactan. It was first reported as a druggable target on the basis of inhibitors discovered in high throughput screening of a drug library. Since then, inhibitors with different types of chemical scaffolds have been reported for their activity against this enzyme. Formation of a covalent or noncovalent bond by the interacting ligand with the enzyme causes loss of its catalytic activity which ultimately leads to the death of the mycobacterium. This Perspective describes various DprE1 inhibitors as anti-TB agents reported to date.

Benzo[d]thiazole-2-carbanilides as new anti-TB chemotypes: Design, synthesis, biological evaluation, and structure-activity relationship

Tuberculosis is the second leading cause of deaths worldwide. The inadequacy of existing drugs to treat TB due to developed resistance and TB-HIV synergism urges for new anti-TB drugs. Seventy-two benzo[d]thiazole-2-carbanilides have been synthesized through CDI-mediated direct coupling of benzo[d]thiazole-2-carboxylic acids with aromatic amines using a three step methodology which includes a green protocol for synthesis of ethyl benzo[d]thiazole-2-carboxylates, precursor of the desired carboxylic acids. The compounds were evaluated in vitro for anti-tubercular activity against M. tuberculosis H₃₇Rv (ATCC27294 strain). Thirty-two compounds exhibiting MIC values in the range of 0.78-6.25 μg/mL (1.9-23 μM) were subjected to cell viability test against RAW 264.7 cell lines and thirty compounds were found to be non-toxic (<50% inhibition). The most active compounds with MIC of 0.78 μg/mL (e.g., 4i, 4n, 4s, 4w, 6f, 6h, 6u, 7e, 7h, 7p, 7r and 7w) exhibit therapeutic index of 64. The structure activity relationship of the N-arylbenzo[d]thiazole-2-carboxamides has been established for anti-mycobacterial activity. Molecular docking suggests that the compounds 7w, 4i and 4n bind to the catalytic site of the enzyme ATP Phosphoribosyltransferase (HisG) and might be attributed to their anti-TB potential. These can serve as a new starting point for the development of anti-TB agents with therapeutic potential.

Long-term bedaquiline-related treatment outcomes in patients with extensively drug-resistant tuberculosis from South Africa

Optimal treatment regimens for patients with extensively drug-resistant tuberculosis (XDR-TB) remain unclear. Long-term prospective outcome data comparing XDR-TB regimens with and without bedaquiline from an endemic setting are lacking.We prospectively followed-up 272 South African patients (49.3% HIV-infected; median CD4 count 169 cells·µL^-1) with newly diagnosed XDR-TB between 2008 and 2017. Outcomes were compared between those who had not received bedaquiline (pre-2013; n=204) and those who had (post-2013; n=68; 80.9% received linezolid in addition).The 24-month favourable outcome rate was substantially better in the bedaquiline versus the non-bedaquiline group (66.2% (45 out of 68) versus 13.2% (27 out of 204); p<0.001). In addition, the bedaquiline group exhibited reduced 24-month rates of treatment failure (5.9% versus 26.0%; p<0.001) and default (1.5% versus 15.2%; p<0.001). However, linezolid was withdrawn in 32.7% (18 out of 55) of patients in the bedaquiline group because of adverse events. Admission weight >50 kg, an increasing number of anti-TB drugs and bedaquiline were independent predictors of survival (the bedaquiline survival effect remained significant in HIV-infected persons, irrespective of CD4 count).XDR-TB patients receiving a backbone of bedaquiline and linezolid had substantially better favourable outcomes compared to those not using these drugs. These data inform the selection of XDR-TB treatment regimens and roll-out of newer drugs in TB-endemic countries.

Ethambutol toxic optic neuropathy: A case report and review

This article presents a case of ethambutol toxic optic neuropathy determined during the routine optometric examination of a 66-year-old man. Ethambutol is an established drug for the treatment of tuberculosis, but has significant side effects, notably optic neuropathy. The prognosis for vision restoration is unpredictable, with the possibility of permanent vision loss. Treatment cessation is the only option to limit ocular damage; therefore, the early recognition of ethambutol optic neuropathy by optometrists is essential.

Forecasting the incidence of tuberculosis in China using the seasonal auto-regressive integrated moving average (SARIMA) model

Objectives

The aims of this study were to develop a forecasting model for the incidence of tuberculosis (TB) and analyze the seasonality of infections in China; and to provide a useful tool for formulating intervention programs and allocating medical resources.

Methods

Data for the monthly incidence of TB from January 2004 to December 2015 were obtained from the National Scientific Data Sharing Platform for Population and Health (China). The Box–Jenkins method was applied to fit a seasonal auto-regressive integrated moving average (SARIMA) model to forecast the incidence of TB over the subsequent six months.

Results

During the study period of 144 months, 12,321,559 TB cases were reported in China, with an average monthly incidence of 6.4426 per 100,000 of the population. The monthly incidence of TB showed a clear 12-month cycle, and a seasonality with two peaks occurring in January and March and a trough in December. The best-fit model was SARIMA (1,0,0)(0,1,1)₁₂, which demonstrated adequate information extraction (white noise test, p > 0.05). Based on the analysis, the incidence of TB from January to June 2016 were 6.6335, 4.7208, 5.8193, 5.5474, 5.2202 and 4.9156 per 100,000 of the population, respectively.

Conclusions

According to the seasonal pattern of TB incidence in China, the SARIMA model was proposed as a useful tool for monitoring epidemics.

Chemical probes and drug leads from advances in synthetic planning and methodology

Screening of small-molecule libraries is a productive method for identifying both chemical probes of disease-related targets and potential starting points for drug discovery. In this article, we focus on strategies such as diversity-oriented synthesis that aim to explore novel areas of chemical space efficiently by populating small-molecule libraries with compounds containing structural features that are typically under-represented in commercially available screening collections. Drawing from more than a decade's worth of examples, we highlight how the design and synthesis of such libraries have been enabled by modern synthetic chemistry, and we illustrate the impact of the resultant chemical probes and drug leads in a wide range of diseases.

Management of drug-resistant tuberculosis in special sub-populations including those with HIV co-infection, pregnancy, diabetes, organ-specific dysfunction, and in the critically ill

Tuberculosis remains a major problem globally, and is the leading cause of death from an infectious agent. Drug-resistant tuberculosis threatens to marginalise the substantial gains that have recently been made in the fight against tuberculosis. Drug-resistant TB has significant associated morbidity and a high mortality, with only half of all multidrug-resistant TB patients achieving a successful treatment outcome. Patients with drug-resistant TB in resource-poor settings are now gaining access to newer and repurposed anti-tuberculosis drugs such as bedaquiline, delamanid and linezolid. However, with ever increasing rates of co-morbidity, there is little guidance on how to manage complex patients with drug-resistant TB. We address that knowledge gap, and outline principles underpinning the management of drug-resistant TB in special situations including HIV co-infection, pregnancy, renal disease, liver disease, diabetes, and in the critically ill.

Stratification by interferon-γ release assay level predicts risk of incident TB

INTRODUCTION

Targeted testing and treatment of latent TB infection (LTBI) are priorities on the global health agenda, but LTBI management remains challenging. We aimed to evaluate the prognostic value of the QuantiFERON TB-Gold (QFT) test for incident TB, focusing on the interferon (IFN)-γ level, when applied in routine practice in a low TB incidence setting.

METHODS

In this large population-based prospective cohort, we linked QFT results in Norway (1 January 2009-30 June 2014) with national registry data (Norwegian Surveillance System for Infectious Diseases, Norwegian Prescription Database, Norwegian Patient Registry and Statistics Norway) to assess the prognostic value of QFT for incident TB. Participants were followed until 30 June 2016. We used restricted cubic splines to model non-linear relationships between IFN-γ levels and TB, and applied these findings to a competing risk model.

RESULTS

The prospective analyses included 50 389 QFT results from 44 875 individuals, of whom 257 developed TB. Overall, 22% (n=9878) of QFT results were positive. TB risk increased with the IFN-γ level until a plateau level, above which further increase was not associated with additional prognostic information. The HRs for TB were 8.8 (95% CI 4.7 to 16.5), 19.2 (95% CI 11.6 to 31.6) and 31.3 (95% CI 19.8 to 49.5) times higher with IFN-γ levels of 0.35 to <1.00, 1.00 to <4.00 and >4.00 IU/mL, respectively, compared with negative tests (<0.35 IU/mL).

CONCLUSIONS

Consistently, QFT demonstrates increased risk of incident TB with rising IFN-γ concentrations, indicating that IFN-γ levels may be used to guide targeted treatment of LTBI.

Isolated Iliac Crest Tuberculosis: A Case Report

CASE

Following an insidious onset of symptoms, a 29-year-old man who had no risk factors for tuberculosis was diagnosed with tuberculosis of the iliac crest. The red flag in this case was the patient's progressive deterioration despite a variety of antibiotic regimens. Histopathologic demonstration of necrotic granulomatous inflammation and a positive culture led to the diagnosis. A combination of surgery and antitubercular-drug therapy resulted in clinical recovery.

CONCLUSION

Iliac crest tuberculosis represents <1% of all skeletal tuberculosis cases. Even in the absence of classic symptoms and risk factors, orthopaedic surgeons should maintain a low threshold for tuberculosis in the differential diagnosis.

An explanation for the low proportion of tuberculosis that results from transmission between household and known social contacts

We currently have little idea where Mycobacterium tuberculosis (Mtb) transmission occurs in high incidence settings. Molecular studies suggest that only around 8-19% of transmission to adults occurs within-household, or between known social-contacts. This contrasts with findings from social-contact studies, which show that substantial proportions of contact time occur in households, workplaces and schools. A mathematical model of social-contact behaviour and Mtb transmission was developed, incorporating variation in susceptibility and infectiousness. Three types of contact were simulated: household, repeated (individuals outside household contacted repeatedly with daily-monthly frequency) and non-repeated. The model was parameterised using data from Cape Town, South Africa, on mean and variance in contact numbers and contact durations, by contact type, and fitted to an estimate of overdispersion in numbers of secondary cases ('superspreading') in Cape Town. Household, repeated, and non-repeated contacts contributed 36%, 13%, and 51% of contact time, and 13%, 8%, and 79% of disease, respectively. Results suggest contact saturation, exacerbated by long disease durations and superspreading, cause the high proportion of transmission between non-repeated contacts. Household and social-contact tracing is therefore unlikely to reach most tuberculosis cases. A better understanding of transmission locations, and methods to identify superspreaders, are urgently required to improve tuberculosis prevention strategies.

Tuberculosis in South Asia: a tide in the affairs of men

Background

Tuberculosis (TB) remains the most common cause of infectious disease deaths worldwide. What is perhaps less appreciated is that the caseload of tuberculosis patients in South Asia is staggering.South Asia has almost 40% of the global TB burden with 4,028,165 cases in 2015. This region also has a disproportionate share of TB deaths (681,975 deaths, 38% of the global burden). Worldwide just 12.5% of TB cases are in HIV positive individuals, but much research and investment has focused on HIV-associated TB. Only 3.5% of patients with tuberculosis in South Asia have HIV co-infection. Not surprisingly with such a huge burden of disease, this region has an estimated 184,336 multi drug resistant (MDR) cases among notified TB cases which accounts for a third of global MDR burden. Crucially, at least 70% of the estimated MDR cases remain untreated in this region and MDR treatment success ranged from only 46% for India to 88% for Sri Lanka in the 2012 cohort that received treatment. This region represents many of the drivers of the modern TB epidemic: rapid urbanization and high density populations with dramatically rising incidence of diabetes, a burgeoning and largely unregulated private sector with escalating drug resistance and high air pollution both outdoor and household.

Conclusion

From bacterial biochemistry to policy implementation, we suggest ways in which South Asia can seize the opportunity lead global TB elimination by demonstrating feasibility in some of the world's most densely populated cities and remotest reaches of the Himalayas. Clearly political will is essential, but we cannot defeat TB without understanding how to eliminate it in South Asia.

Can aspirin help?

Using a combination of aspirin, anti-tuberculosis drugs and steroids may help to reduce the number of strokes and deaths in patients with tuberculous meningitis.

Limitations of Serum Ferritin in Diagnosing Iron Deficiency in Inflammatory Conditions

Patients with inflammatory conditions such as inflammatory bowel disease (IBD), chronic heart failure (CHF), and chronic kidney disease (CKD) have high rates of iron deficiency with adverse clinical consequences. Under normal circumstances, serum ferritin levels are a sensitive marker for iron status but ferritin is an acute-phase reactant that becomes elevated in response to inflammation, complicating the diagnosis. Proinflammatory cytokines also trigger an increase in hepcidin, which restricts uptake of dietary iron and promotes sequestration of iron by ferritin within storage sites. Patients with inflammatory conditions may thus have restricted availability of iron for erythropoiesis and other cell functions due to increased hepcidin expression, despite normal or high levels of serum ferritin. The standard threshold for iron deficiency (<30 μg/L) therefore does not apply and transferrin saturation (TSAT), a marker of iron availability, should also be assessed. A serum ferritin threshold of <100 μg/L or TSAT < 20% can be considered diagnostic for iron deficiency in CHF, CKD, and IBD. If serum ferritin is 100-300 μg/L, TSAT < 20% is required to confirm iron deficiency. Routine surveillance of serum ferritin and TSAT in these at-risk groups is advisable so that iron deficiency can be detected and managed.

Impact of Health Education on Knowledge and Behaviors toward Infectious Diseases among Students in Gansu Province, China

Objectives

Infectious disease knowledge and behaviors are key elements that ensure student health and safety. This study explores the impact of health education on student knowledge and behaviors toward infectious diseases and determines the factors affecting infectious diseases knowledge and behaviors among students in Gansu, China.

Methods

A cross-sectional study and three sampling methods were used in two counties, 12 schools, and 32 classes in Gansu, China, from 2012 to 2013. Collected data included the following: (1) sociodemographic characteristics of 2002 students (1001 participants in the intervention group and 1001 in the control group); (2) accuracy of student knowledge and behaviors toward infectious diseases based on comparison of intervention and control groups through X² test; and (3) mean scores on knowledge and behavior of students with different characteristics toward infectious diseases, as analyzed through analysis of variance (ANOVA). Multiple linear regression was conducted to analyze factors affecting student knowledge and behaviors toward infectious diseases.

Results

Statistically significant differences were observed among eight items of infectious disease transmission and treatment knowledge between intervention and control groups (P < 0.001). Average accuracies of knowledge and behaviors toward infectious diseases reached 72.23% and 60.03%. Significant differences were observed in six items on student behavior in rural and urban areas (P < 0.001). Health education, household register, and county affected scores of student knowledge and behaviors toward infectious diseases (P < 0.05). Gender and education level also affected scores of student behaviors toward infectious diseases (P < 0.001).

Conclusions

Health education contributes to student knowledge and behaviors toward infectious diseases. Students in the control group need intensified health education on infectious diseases. Health education needs to pay particular attention to rural students, all male students, and students at senior high school level living on campus.

The convergent epidemiology of tuberculosis and human cytomegalovirus infection

Although several factors are known to increase the risk of tuberculosis, the occurrence of tuberculosis disease in an infected individual is difficult to predict. We hypothesize that active human cytomegalovirus infection due to recent infection, reinfection or reactivation plays an epidemiologically relevant role in the aetiology of tuberculosis by precipitating the progression from latent tuberculosis infection to disease. The most compelling support for this hypothesis comes from the striking similarity in age-sex distribution between the two infections, important because the age-sex pattern of tuberculosis disease progression has not been convincingly explained. Cytomegalovirus infection and tuberculosis have other overlapping risk factors, including poor socio-economic status, solid organ transplantation and, possibly, sexual contact and whole blood transfusion. Although each of these overlaps could be explained by shared underlying risk factors, none of the epidemiological observations refute the hypothesis. If this interaction would play an epidemiologically important role, important opportunities would arise for novel approaches to controlling tuberculosis.

The convergent epidemiology of tuberculosis and human cytomegalovirus infection

Although several factors are known to increase the risk of tuberculosis, the occurrence of tuberculosis disease in an infected individual is difficult to predict. We hypothesize that active human cytomegalovirus infection due to recent infection, reinfection or reactivation plays an epidemiologically relevant role in the aetiology of tuberculosis by precipitating the progression from latent tuberculosis infection to disease. The most compelling support for this hypothesis comes from the striking similarity in age-sex distribution between the two infections, important because the age-sex pattern of tuberculosis disease progression has not been convincingly explained. Cytomegalovirus infection and tuberculosis have other overlapping risk factors, including poor socio-economic status, sexual contact, whole blood transfusion and solid organ transplantation. Although each of these overlaps could be explained by shared underlying risk factors, none of the epidemiological observations refute the hypothesis. If this interaction would play an epidemiologically important role, important opportunities would arise for novel approaches to controlling tuberculosis.

Vitamin D, cod liver oil, sunshine, and phototherapy: Safe, effective and forgotten tools for treating and curing tuberculosis infections - A comprehensive review

Tuberculosis remains an epidemic throughout the world, with over 2 billion people, or more than one third of the world's population, infected with TB. In 2015, there were an estimated 10.4 million new cases of tuberculosis, and 1.8 million deaths, making TB one of the top ten causes of death worldwide. Approximately 95% of new TB cases occur in developing countries, where the costs of treatment force many patients and their families into poverty. The United Nations and the World Health Organization are working to end this global epidemic. Historically, cod liver oil in the 1840's, phototherapy in the 1890's, sunshine in the 1890's and 1930's, oral vitamin D in doses of 100,000-150,000 international units a day the 1940's, and injectable vitamin D in the 1940's were all shown to be able to safely treat tuberculosis. However, for reasons that are unclear, these treatments are no longer being used to treat tuberculosis. We will review several reports that documented the clinical efficacy of these seemingly disparate treatments in treating tuberculosis. Taken together, however, these reports show the consistent efficacy of vitamin D in treating tuberculosis infections, regardless of whether the vitamin D was produced in the skin from the effects of phototherapy or sunshine, taken orally as a pill or in cod-liver oil, or put into solution and injected directly into the body. We will discuss how vitamin D, through its action as a steroid hormone that regulates gene transcription in cells and tissues throughout the body, enables the body to eradicate TB by stimulating the formation of a natural antibiotic in white blood cells, the mechanism of which was discovered in 2006. We will speculate as to why vitamin D, cod liver oil, sunshine, and phototherapy are no longer being used to treat tuberculosis, in spite of their proven efficacy in safely treating this disease dating back to the early 1800's. In fact, in 1903 the Nobel Prize in Medicine or Physiology was awarded to a physician who was able to cure hundreds of cases of long-standing lupus vulgaris (cutaneous TB) with refracted light rays from an electric arc lamp. Vitamin D, cod liver oil, sunshine, and phototherapy have never been shown to lose their ability to safely eradicate tuberculosis infections, and deserve consideration to be re-examined as first-line treatments for tuberculosis. These treatments have the potential to help cost-effectively and safely end the global TB epidemic.

False-Positive Xpert MTB/RIF Results in Retested Patients with Previous Tuberculosis: Frequency, Profile, and Prospective Clinical Outcomes

Globally, Xpert MTB/RIF (Xpert) is the most widely used PCR test for the diagnosis of tuberculosis (TB). Positive results in previously treated patients, which are due to old DNA or active disease, are a diagnostic dilemma. We prospectively retested sputum from 238 patients, irrespective of current symptoms, who were previously diagnosed to be Xpert positive and treated successfully. Patients who retested as Xpert positive and culture negative were exhaustively investigated (repeat culture, chest radiography, bronchoscopy with bronchoalveolar lavage, long-term clinical follow-up). We evaluated whether the duration since previous treatment completion, mycobacterial burden (the Xpert cycle threshold [C_T ] value), and reclassification of Xpert-positive results with a very low semiquantitation level to Xpert-negative results reduced the rate of false positivity. A total of 229/238 (96%) of patients were culture negative. Sixteen of 229 (7%) were Xpert positive a median of 11 months (interquartile range, 5 to 19 months) after treatment completion. The specificity was 93% (95% confidence interval [CI], 89 to 96%). Nine of 15 (40%) Xpert-positive, culture-negative patients reverted to Xpert negative after 2 to 3 months (1 patient declined further participation). Patients with false-positive Xpert results had a lower mycobacterial burden than patients with true-positive Xpert results (C_T , 28.7 [95% CI, 27.2 to 30.4] versus 17.6 [95% CI, 16.9 to 18.2]; P < 0.001), an increased likelihood of a chest radiograph not compatible with active TB (5/15 patients versus 0/5 patients; P = 0.026), and less-viscous sputum (15/16 patients versus 2/5 patients whose sputum was graded as mucoid or less; P = 0.038). All patients who initially retested as Xpert positive and culture negative ("Xpert false positive") were clinically well without treatment after follow-up. The duration since the previous treatment poorly predicted false-positive results (a duration of ≤2 years identified only 66% of patients with false-positive results). Reclassifying Xpert-positive results with a very low semiquantitation level to Xpert negative improved the specificity (+3% [95% CI, +2 to +5%]) but reduced the sensitivity (-10% [95% CI, -4 to -15%]). Patients with previous TB retested with Xpert can have false-positive results and thus not require treatment. These data inform clinical practice by highlighting the challenges in interpreting Xpert-positive results, underscore the need for culture, and have implications for next-generation ultrasensitive tests.

Effects of fluconazole on the clinical outcome and immune response in fungal co-infected tuberculosis patients

With overuse of the broad-spectrum antibiotics, the pulmonary fungal infection increasingly becomes the most common complication associated with senile pulmonary tuberculosis (TB) and attracts intensive attentions from clinicians. Here we presented the retrospective analysis of impact of fluconazole treatment on the clinical outcome and immune response in fungal co-infected tuberculosis patients. A randomized, double-blind, placebo-controlled trial of fluconazole (100 mg per day for consecutive weeks) in fungal-positive senile tuberculosis patients was conducted in our hospital. Peripheral eosinophil counts were computed by the automatic hematology analyzer. The secretory inflammatory cytokines interferon (IFN)-γ, tumor necrosis factor (TNF)-α and chemokines chemokine C-X-C motif ligand (CXCL)9, CXCL10, CXCL11 were determined with enzyme-linked immunosorbent assay kits. The peripheral T helper 1 cells (Th1) and regulatory T cells (Treg) population were analyzed by flow cytometry. None of significant difference in respect to baseline TB score was observed between placebo and fluconazole groups. Administration of fluconazole significantly stimulated eosinophils population and secretion of inflammatory cytokines IFN-γ and TNF-α. Simultaneously, the peripheral Th1% and chemokines including CXCL9, CSCL10, CXCL11 were markedly induced in response to fluconazole treatment. Fungal infection significantly affected host immunity during tuberculosis which was effectively reversed by fluconazole treatment.

Sputum bacteriology conversion and treatment outcome of patients with multidrug-resistant tuberculosis

Purpose

Multidrug-resistant tuberculosis (MDR-TB) requires long-term treatment, has a high fatality rate, and constitutes a global threat. Earlier detection of treatment failure is required to predict therapeutic efficacy.

Patients and methods

We enrolled MDR-TB patients consecutively from January 2011 through December 2012 in Lianyungang, China. Sputum smear microscopy tests and sputum cultures were performed once a month for the first 6 months following initiation of antituberculosis treatment and once every 2 months thereafter until the end of therapy. The sensitivity, specificity and area under the receiver operating characteristic curve (AUC) were used with a 95% CI to estimate the role of sputum bacteriology conversion in predicting treatment outcomes.

Results

Among the 92 MDR-TB patients enrolled in this study, 40.2% had poor treatment outcomes. The median initial sputum bacteriology conversion time was 1 month. Patients having 2-month sputum smear conversions (adjusted odds ratio [OR]: 7.19, 95% CI: 2.60–19.84) or culture conversions (adjusted OR: 2.88, 95% CI: 1.11–7.45) were more likely to experience good outcomes. The sensitivity and specificity obtained when using two-month sputum smear conversions to predict treatment outcomes were 67.6% (95% CI: 50.2–82.0) and 76.4% (95% CI: 63.0–86.8), respectively. The sensitivity and specificity obtained when using 2-month culture conversions to predict treatment outcomes were 48.6% (95% CI: 32.0–65.6) and 74.5% (95% CI: 61.0–85.3), respectively. The AUC for two-month smear conversions was 0.72 (95% CI: 0.62–0.81), significantly higher than that obtained for 2-month culture conversions (0.62, 95% CI: 0.52–0.72) (χ² = 4.18, P = 0.041).

Conclusion

The prognoses of MDR-TB patients displaying persistent sputum positivity were inferior to those for whom sputum bacteriology conversion was observed. Thus, sputum smear conversion results obtained 2 months after treatment initiation may provide a potential means for predicting MDR-TB treatment outcomes.

Intracisternal tuberculoma: a refractory type of tuberculoma indicating surgical intervention

Background

Central nervous system (CNS) tuberculoma is a rare disease with severe neurological deficits. This retrospective research is to review the data of patients diagnosed as CNS tuberculoma. Surgeries were performed in all patients. The clinical features especially the neurological image and the anatomical characters of the tuberculomas were concerned.

Methods

Totally 11 patients diagnosed as CNS tuberculoma were admitted in Guangzhou First People’s Hospital (7cases) and Changzheng Hospital (4 cases) during 2006–2015. The data including preoperative condition, neurological imaging, and surgical findings was collected and analyzed.

Results

The lesions of nine patients (9/11) were totally or subtotally excised and two (2/11) were partially excised. Neurological functions of all patients were improved after surgery without secondary infection. Lesions of nine (9/11) patients preoperatively progressed as a result of paradoxical reaction. Of the 9 patients demonstrated paradoxical progression, all lesions were partially or totally located at the cisterns or the subarachnoid space. Preoperative ATTs lasted 2 to 12 months and tuberculomas were not eliminated. The arachnoid was found thickened and tightly adhered to the lesions during surgeries. Of the 2 cases that paradoxical reaction were excluded, both patients (case 6, intramedullary tuberculoma; case 11, intradural extramedullary tuberculoma) were admitted at onset of the disease. ATTs were preoperatively given for 1 week as neurological deficits aggravated. The tuberculous lesions of CNS or other system showed no obvious change and paradoxical reaction could not be established in both cases.

Conclusions

Exudates of tuberculosis is usually accumulated in the cisterns and frequently results in the paradoxical formation of tuberculoma. Intracisternal tuberculoma is closely related to paradoxical reaction and refractory to anti-tuberculosis therapy. Micro-surgical excision is safe and effective. Early surgical intervention may be considered in the diagnosis of intracisternal tuberculoma especially when paradoxical reaction participates in the development of tuberculoma.

Antimicrobial resistance in Mycobacterium tuberculosis: mechanistic and evolutionary perspectives

Antibiotic-resistant Mycobacterium tuberculosis strains are threatening progress in containing the global tuberculosis epidemic. Mycobacterium tuberculosis is intrinsically resistant to many antibiotics, limiting the number of compounds available for treatment. This intrinsic resistance is due to a number of mechanisms including a thick, waxy, hydrophobic cell envelope and the presence of drug degrading and modifying enzymes. Resistance to the drugs which are active against M. tuberculosis is, in the absence of horizontally transferred resistance determinants, conferred by chromosomal mutations. These chromosomal mutations may confer drug resistance via modification or overexpression of the drug target, as well as by prevention of prodrug activation. Drug resistance mutations may have pleiotropic effects leading to a reduction in the bacterium's fitness, quantifiable e.g. by a reduction in the in vitro growth rate. Secondary so-called compensatory mutations, not involved in conferring resistance, can ameliorate the fitness cost by interacting epistatically with the resistance mutation. Although the genetic diversity of M. tuberculosis is low compared to other pathogenic bacteria, the strain genetic background has been demonstrated to influence multiple aspects in the evolution of drug resistance. The rate of resistance evolution and the fitness costs of drug resistance mutations may vary as a function of the genetic background.

Clinical study of tuberculosis in the head and neck region-11 years' experience and a review of the literature

Tuberculosis (TB) is an infectious disease and major health concern. Head and neck tuberculosis (HNTB) is relatively rare, but can arise in many regions, including the lymph nodes, larynx, oral cavity and pharynx. We retrospectively reviewed the clinical records of 60 patients diagnosed with HNTB in our department between March 2005 and January 2016. A review and summary of previous HNTB articles published in PubMed since 1885 was also performed. The subjects consisted of 17 males and 43 females, and the average age of patients was 45 ± 14.67 years. The major clinical presentation was a lump or swelling, followed by an oral ulcer and skin fistula. The most common site of tuberculosis was in the cervical lymph node. Three patients also suffered from a malignant tumor in the head and neck region. A total of 980 papers involving 5881 patients were included in our literature review. The included subjects ranged in age from 15 months to 100 years with a male-to-female ratio of 1.5:1. The larynx (38.92%), cervical lymph nodes (38.28%) and oral cavity (9.92%) were the three most common development sites. 465 patients were positive according to a HIV test, and 40 patients had comorbidities with different types of tumors. Head and neck tuberculosis should always be considered during a differential diagnosis for lesions in the head and neck region. Early diagnosis and treatment can greatly enhance the therapeutic effect and patients’ quality of life.

Diagnosing tuberculosis in hospitalized HIV-infected individuals who cannot produce sputum: is urine lipoarabinomannan testing the answer?

Background

Up to one third of HIV-infected individuals with suspected TB are sputum-scarce. The Alere Determine™ TB LAM Ag lateral flow strip test can be used to diagnose TB in HIV-infected patients with advanced immunosuppression. However, how urine LAM testing should be incorporated into testing algorithms and in the context of specific patient sub-groups remains unclear.

Methods

This study represents a post hoc sub-group analysis of data from a randomized multi-center parent study. The study population consisted of hospitalized HIV-infected patients with suspected TB who were unable to produce sputum and who underwent urine LAM testing. The diagnostic utility of urine LAM for TB in this group was compared to the performance of urine LAM in patients who did produce a sputum sample in the parent study.

Results

There were a total of 187 and 2341 patients in the sputum-scarce and sputum-producing cohorts, respectively. 80 of the sputum-scarce patients underwent testing with urine LAM. In comparison to those who did produce sputum, sputum-scarce patients had a younger age, a lower Karnofsky performance score, and a lower weight and BMI at admission. A greater proportion of sputum-scarce patients were urine LAM positive, compared to those who were able to produce sputum (31% vs. 21%, p = 0.04). A higher proportion of sputum-scarce patients died within 8 weeks of admission (32% vs. 24%, p = 0.013). We inferred that 19% of HIV-infected sputum-scarce patients suspected of TB were diagnosed with tuberculosis by urine LAM testing, with an estimated positive predictive value of 63% (95% CI 43–82%).

Conclusions

Urine LAM testing can effectively identify tuberculosis in HIV-infected patients who are at a higher risk of mortality yet are unable to generate a sputum sample for diagnostic testing. Our findings support the use of urine LAM testing in sputum-scarce hospitalized HIV-infected patients, and its incorporation into diagnostic algorithms for this patient population.