Tuberkulose

AbstractBackgroundHypertension induces systemic inflammation, but its impact on the outcome of infectious diseases like tuberculosis (TB) is unknown. Calcium channel blockers (CCB) improve TB treatment outcomes in pre-clinical models, but their effect in patients with TB remain unclear.MethodsThis retrospective cohort study, including all patients > 18 years receiving treatment for culture-confirmed, drug-sensitive TB from 2000 to 2016 at the National Taiwan University Hospital, assessed the association of hypertension and CCB use with all-cause and infection-related mortality during the first 9 months of TB treatment, as well as sputum-smear microscopy and sputum-culture positivity at 2 and 6 months.Results1052 of the 2894 patients (36.4%) had hypertension. Multivariable analysis revealed that hypertension was associated with increased mortality due to all causes (HR 1.57, 95% confidence interval[CI], 1.23-1.99) and infections (HR 1.87, 95%CI, 1.34-2.6), but there was no statistical difference in microbiological outcomes when stratified based on hypertensive group. Dihydropyridine-CCB (DHP-CCB) use was associated with reduced all-cause mortality (HR 0.67, 95%CI: 0.45-0.98) only by univariate Cox regression. There was no association between DHP-CCB use and infection-related mortality (HR 0.78, 95%CI: 0.46-1.34) or microbiological outcomes in univariate or multivariate regression analyses.ConclusionsPatients with hypertension have increased all-cause mortality and infection-related mortality during the 9 months following TB treatment initiation. DHP-CCB use may lower all-cause mortality in TB patients with hypertension. The presence of hypertension or the use of CCB did not result in a significant change in microbiological outcomes.

Abstract Objectives To investigate the incidence of active tuberculosis (TB) among COPD patients using fluticasone/salmeterol or budesonide/formoterol, and to identify any differences between these two groups of patients. Methods The study enrolled COPD patients from Taiwan NHIRD who received treatment with fluticasone/salmeterol or budesonide/formoterol for > 90 days between 2004 and 2011. The incidence of active TB was the primary outcome. Results Among the intention-to-treat population prior to matching, the incidence rates of active TB were 0.94 and 0.61% in the fluticasone/salmeterol and budesonide/formoterol groups, respectively. After matching, the fluticasone/salmeterol group had significantly higher rates of active TB (adjusted HR, 1.41, 95% CI, 1.17–1.70) compared with the budesonide/formoterol group. The significant difference between these two groups remained after a competing risk analysis (HR, 1.45, 95% CI, 1.21–1.74). Following propensity score matching, the fluticasone/salmeterol group had significantly higher rates of active TB compared with the budesonide/formoterol group (adjusted HR, 1.45, 95% CI, 1.14–1.85). A similar trend was observed after a competing risk analysis (HR, 1.44, 95% CI, 1.19–1.75). A higher risk of active TB was observed in the fluticasone/salmeterol group compared with the budesonide/formoterol group across all subgroups, but some differences did not reach statistical significance. Conclusion Fluticasone/salmeterol carried a higher risk of active TB compared with budesonide/formoterol among COPD patients.…

AbstractBackgroundMycobacterium tuberculosis (Mtb), the bacterium that causes tuberculosis (TB), causes 10 million infections and 1.5 million deaths per year worldwide. The success of Mtb as a human pathogen is directly related to its ability to suppress host responses, which are critical for clearing intracellular pathogens. Emerging evidence suggests that key response pathways may be regulated by a novel class of small non-coding RNA, called tRNA-derived fragments (tRFs). tRFs can complex with Argonaute proteins to target and degrade mRNA targets, similarly to miRNAs, but have thus far been overlooked in the context of bacterial infections.MethodsWe generate a novel miRge2.0-based tRF-analysis tool, tRFcluster, and use it to analyze independently-generated and publicly available RNA-sequencing datasets to assess tRF dysregulation in host cells following infection with Mtb and other intracellular bacterial pathogens.ResultsWe find that Mtb and Listeria monocytogenes drive dramatic tRF dysregulation, whereas other bacterial pathogens do not. Interestingly, Mtb infection uniquely increased the expression of mitochondria-derived tRFs rather than genomic-derived tRFs, suggesting an association with mitochondrial damage in Mtb infection.ConclusionstRFs are dysregulated in some, but not all, bacterial infections. Biased dysregulation of mitochondria-derived tRFs in Mtb infection suggests a link between mitochondrial distress and tRF production.

Introduction Although Bangladesh is a country of generalised tuberculosis (TB) epidemic, the HIV prevalence is low among general populations, and 3.9% among key populations. Despite the high possibility of HIV–TB coinfection, scientifically tested approaches for increasing TB case detection among sexual minority people are yet to be developed and implemented in Bangladesh. Such approaches could foster service delivery linkages between communities and the government health system. Findings of this experimental research are likely to provide new insights for programme managers and policy planners for adopting a similar approach in order to enhance TB referral, thus ultimately increasing TB case detections and reducing the likelihood of TB-related mortalities and morbidities, irrespective of HIV status. Methods and analysis This operational research will follow a quasi-experimental design, applying both qualitative and quantitative methods, in two drop-in centres in three phases. Phase 1 will encompass baseline data collection and development of a community-based TB screening approach. In phase 2, the newly developed intervention will be implemented, followed by end-line data collection in phase 3. Qualitative data collection will be continued throughout the first and second phases. The baseline and end-line data will be compared both in the intervention and comparison areas to measure the impact of the intervention. Ethics and dissemination Ethical approval was obtained from the Institutional Review Board of International Centre for Diarrhoeal Disease Research, Bangladesh. The findings will be disseminated through diverse scientific forums including peer-reviewed journals, presentation at conferences and among the policy-makers for policy implication. The study started in January 2019 and will continue until June 2020.…

S. Homolka et al.

High risk healthcare workers (HCWs) are often screened for latent tuberculosis infection (LTBI) using QuantiFERON tests (QFTs), with annual serial tests often showing reversion from positive to negative results. We assessed the frequency of and risk factors for reversion of QFTs in HCWs in an intermediate-tuberculosis burden country.

Spiroketal indolyl Mannich bases (SIMBs) present a novel class of membrane-inserting antimycobacterials with efficacy in a tuberculosis mouse model. SIMBs exert their antibacterial activity by two mechanisms. The indolyl Mannich base scaffold causes permeabilization of bacteria and the spiroketal moiety contributes to inhibition of the mycolic acid transporter MmpL3. Here, we show that low-level resistance to SIMBs arises by mutations in the transcriptional repressor MmpR5 resulting in upregulation of the efflux pump MmpL5.…

Preclinical animal models of infection are employed to develop new agents, but also to screen among molecules to rank them. There are often major differences between human pharmacokinetic profiles and those developed by animal models of infection and may lead to substantial differences in efficacy relative to that seen in man. Linezolid is a repurposed agent employed to great effect for therapy of Mycobacterium tuberculosis. In this study, we used the Hollow Fiber Infection Model (HFIM) to evaluate the impact of different pharmacokinetic profiles of mice and Non-Human Primates (NHP) versus Humans on bacterial cell kill as well as resistance suppression. We examined both plasma and Epithelial Lining Fluid (ELF) profiles. We examined simulated exposures equivalent to 600 mg and 900 mg daily of linezolid in man. For both plasma and ELF exposures, the murine PK profile provided estimates of effect that were biased low relative to human and NHP PK profiles. Mathematical modeling identified a linkage between Cmin concentrations and bacterial kill and Cpeak concentrations and resistance suppression, with the latter being supported by a prospective validation study. Finding new agents with novel mechanisms of action against M. tuberculosis is difficult. It would be a tragedy to discard a new agent because of a biased estimate of effect in a preclinical animal system. The HFIM provides a system to benchmark evaluation of new compounds in preclinical animal model systems against Human PK effects (species scale-up estimates of PK), to safeguard unwarranted rejection of promising new agents.…

New England Journal of Medicine, Volume 383, Issue 12, September 2020. …

Objective We assessed the impact of political conflict (Boko Haram) on tuberculosis (TB) case notifications in Adamawa State in North-east Nigeria. Design A retrospective analysis of TB case notifications from TB registers (2010–2016) to describe changes in TB notification, sex and age ratios by the degree of conflict by local government area. Setting Adamawa State. Participants 21 076 TB cases notified. Results 21 076 cases (62% male) were notified between 2010 and 2016, of which 19 604 (93%) were new TB cases. Areas affected by conflict in 2014 and 2015 had decreased case notification while neighbouring areas reported increased case notifications. The male to female ratio of TB cases changed in areas in conflict with more female cases being notified. The young and elderly (1–14 and >65 years old) had low notifications in all areas, with a small increase in case notifications during the years of conflict. Conclusion TB case notifications decreased in conflict areas and increased in areas without conflict. More males were notified during peace times and more female cases were reported from areas in conflict. Young and elderly populations had decreased case notifications but experienced a slight increase during the conflict years. These changes are likely to reflect population displacement and a dissimilar effect of conflict on the accessibility of services. TB services in conflict areas deserve further study to identify resilient approaches that could reach affected populations.…

Tropical Medicine & International Health, Accepted Article.

Background: On 27th January 2019, A hospital in Chilass city reported 20 suspected pediatric cases of pulmonary tuberculosis. Provincial TB control Program conducted an investigation to identify associated risk factors and recommend measures to prevent future control…

Abstract Background There is limited research to guide TB treatment specifically in pregnant women and few studies have described the presentation of TB in pregnant women. We aimed to understand TB presentation and treatment outcomes in pregnant women in a low HIV burden setting. We describe a cohort of women of childbearing age treated for TB disease in Lima, Peru, and compare clinical presentation and treatment outcomes among pregnant and non-pregnant women between 2009 and 2012, including 36 pregnant women. Methods This is a prospective cohort study. Subjects were recruited from across 106 public health centers in Lima, Peru. Baseline demographic, medical history, and drug-susceptibility test results were collected. We used descriptive statistics to describe demographic and clinical characteristics of the women using Pearson chi-squared, Fisher’s exact tests, or Kruskal-Wallis. Results Among 4500 individuals with pulmonary TB disease, 1334 women were included in analysis with 36 (2.69%) pregnant women. Pregnant women had similar demographics, past medical histories, and clinical presentation to non-pregnant women, except being more likely to be married (p = 0.01) and have cardiac disease (p = 0.04) and less likely to have weight loss (p = 0.05). Twenty (71.4%) pregnant women had pan-susceptible TB compared with 616 (63.1%) non-pregnant women; four (14.3%) pregnant women had mono-resistant TB compared with 154 (15.8%) non-pregnant women; and four (14.3%) pregnant women had multi-drug-resistant TB compared with 140 (14.3%) of non-pregnant women (p = 0.53). Twenty-eight (96.6%) pregnant women had a successful outcome (cure, completed treatment, treatment ended early by clinical team) while one (3.4%) had an unsuccessful outcome (treatment failed) and 1074 (97.3%) non-pregnant women had a successful outcome while 30 (2.7%) had an unsuccessful outcome (p = 0.56). Conclusion In this cohort with low HIV co-infection, we found high TB treatment success rates in both pregnant and non-pregnant women, irrespective of drug-susceptibility profiles. If treated appropriately, pregnant women with TB disease can have successful outcomes.…

Abstract Background Recombinant fusion protein ESAT6-CFP10 (EC) is a newly developed skin test reagent for detecting Mycobacterium tuberculosis (M. tuberculosis) infection. In this study, we evaluated whether induration and erythema could be used as diagnostic indicators for EC skin test to detect M. tuberculosis infection. Methods A total of 743 tuberculosis patients and 1514 healthy volunteers underwent an EC skin test. The diameters of induration and erythema were measured with Vernier caliper, 24 h, 48 h, and 72 h after skin testing. Related indicators of EC reagent diagnostic test were tested, and the diagnostic effects of the four diagnostic indicators for EC skin test were compared. Results The sensitivity of induration / erythema measurement was lower at 24 h after EC skin test than at 48 h or 72 h (P

AbstractPrevious studies demonstrated that Transforming Growth Factor β1 (TGF-β1) plays an immunosuppressive role in clinical tuberculosis (TB). However, the contribution of TGF-β1 gene polymorphisms to human TB susceptibility remains undetermined. In this study, we showed that single nucleotide polymorphisms (SNPs) in TGF-β1 gene were associated with increased susceptibility to TB in the discovery cohort (1533 cases and 1445 controls) and the validation cohort (832 cases and 1084 controls), and two SNPs located in the promoter region (rs2317130 and rs4803457) are in strong linkage disequilibrium. The SNP rs2317130 was associated with the severity of TB. Further investigation demonstrated that rs2317130CC genotype is associated with higher TGF-β1 and IL-17A production. The mechanistic study showed rs2317130 C allele affected TGF-β1 promoter activity through regulating binding activity to nuclear extracts. These findings provide insights into the pathogenic role of TGF-β1 in human TB and reveal a function for the TGF-β1 promoter SNPs in regulating immune responses during Mycobacterium tuberculosis (Mtb) infection.

Globally, ten million tuberculosis (TB) cases and 1·5 million deaths occur annually, with the vast majority reported from low- and middle-income countries (LMICs) (World Health Organization, 2019). Since 1993, many national TB control programs (NTP) have scaled up the Directly Observed Treatment Short Course (DOTS) strategy of passive case finding, standardized treatment allocation and monitoring of treatment adherence for TB control (Matteelli et al., 2018). However, the DOTS strategy was insufficient in achieving global TB elimination goals,2 and active TB case detection strategies are recommended for reducing ongoing community transmission of TB (Ho et al., 2016).

Abstract Background Tuberculosis (TB) control is a primary global health priority but the goal to eliminate TB is being threatened by the increase in incidence of multidrug-resistant tuberculosis (MDR-TB). With this series of seven MDR-TB cases in migrant patients with identical Mycobacterium tuberculosis strains we aim to illustrate the challenges encountered during therapy and follow-up: language barriers, access to care for migrant patients, depression due to isolation, adverse reactions to the treatment, management of pediatric TB, further contact tracing. We also discuss best practices for the management of complex MDR-TB cases in settings with low overall TB incidence focusing on modern diagnostic assays and an individualized and an interdisciplinary therapeutic approach. Methods We describe a case series of seven consecutively diagnosed MDR-TB patients, six of them treated at our tertiary care hospital between May 2018 and March 2020. Epidemiologic data was gained by semi-structured patient interviews and reconstruction of the migration route. The origin of the cluster was confirmed by genotyping of the TB-strains. Results Six related patients were diagnosed with pulmonary MDR-TB between May and August 2018. All had a positive Interferon-Gamma-Release Assay (IGRA), in five patients sputum microscopy was positive for acid-fast bacilli (AFB). The genetic and phenotypical drug susceptibility test did not match with MDR-TB strains from an East-African origin. The index patient was identified through genetical fingerprinting. By changing the therapy to a modern MDR-TB regime and using an interdisciplinary and culture-sensitive approach, all patients improved clinically and radiologically. Conclusion Human migration plays an important role for the global spread of MDR-TB in low incidence countries. Early case detection and adequate treatment are key to prevention of outbreaks. Especially language barriers and complex migration routes make genotyping of TB-strains a crucial tool to identify cases clusters, the potential index patient and transmission dynamics. We are fortunate enough to experience times in which new TB-antibiotics were made available and in which molecular assays revolutionized TB-diagnostics. We need to take advantage of that and develop personalized therapies for patients suffering from drug resistant TB.…

Abstract Background Approximately 80% - 90% of individuals infected with latent Mycobacterium tuberculosis (Mtb) remain protected throughout their life-span. The release of unique, latent-phase antigens are known to have a protective role in the immune response against Mtb. Although the BCG vaccine has been administered for nine decades to provide immunity against Mtb, the number of TB cases continues to rise, thereby raising doubts on BCG vaccine efficacy. The shortcomings of BCG have been associated with inadequate processing and presentation of its antigens, an inability to optimally activate T cells against Mtb, and generation of regulatory T cells. Furthermore, BCG vaccination lacks the ability to eliminate latent Mtb infection. With these facts in mind, we selected six immunodominant CD4 and CD8 T cell epitopes of Mtb expressed during latent, acute, and chronic stages of infection and engineered a multi-epitope-based DNA vaccine (C6). Result BALB/c mice vaccinated with the C6 construct along with a BCG vaccine exhibited an expansion of both CD4 and CD8 T cell memory populations and augmented IFN-γ and TNF-α cytokine release. Furthermore, enhancement of dendritic cell and macrophage activation was noted. Consequently, illustrating the elicitation of immunity that helps in the protection against Mtb infection; which was evident by a significant reduction in the Mtb burden in the lungs and spleen of C6 + BCG administered animals. Conclusion Overall, the results suggest that a C6 + BCG vaccination approach may serve as an effective vaccination strategy in future attempts to control TB.…

AbstractWhile it is known that a substantial proportion of individuals with tuberculosis disease (TB) present subclinically, usually defined as bacteriologically-confirmed but negative on symptom screening, considerable knowledge gaps remain. Our aim was to review data from TB prevalence population surveys and generate a consistent definition and framework for subclinical TB, thus enabling an estimate of the proportion of TB that is subclinical, explore associations with overall burden and programme indicators, and performance of screening strategies. We extracted data from all publicly available prevalence surveys conducted since 1990. Between 36.1–79.7% (median 50.4%) of prevalent bacteriologically-confirmed TB was subclinical. No association was found between prevalence of subclinical and all bacteriologically confirmed TB, patient diagnostic rate or country-level HIV prevalence (p-values, 0.32, 0.4, 0.34, respectively). Chest X-ray detected 89% (range 73–98%) of bacteriologically-confirmed TB disease, highlighting the potential of optimizing current TB case-finding policies.

Immigration from areas of high incidence is thought to have fueled the resurgence of tuberculosis (TB) in areas of low incidence. To reduce the risk of disease in low-incidence areas, the main countermeasure has been the screening of immigrants on arrival. This measure is based on the assumption of a prompt decline in the incidence of TB in immigrants during their first few years of residence in a country with low overall incidence. We have documented that this assumption is not true for 619 Somali immigrants reported in Denmark as having TB. The annual incidence of TB declined only gradually during the first 7 years of residence, from an initial 2,000 per 100,000 to 700 per 100,000. The decline was described by an exponential function with a half-time of 5.7 (95% confidence interval 4.0 to 9.7) years. This finding seriously challenges the adequacy of the customary practice of screening solely on arrival.

As countries approach the elimination phase of tuberculosis, specific problems and challenges emerge, due to the steadily declining incidence in the native population, the gradually increasing importance of the importation of latent tuberculosis infection and tuberculosis from other countries and the emergence of groups at particularly high risk of tuberculosis. Therefore, a Working Group of the World Health Organization (WHO), the International Union Against Tuberculosis and Lung Disease (IUATLD) and the Royal Netherlands Tuberculosis Association (KNCV) have developed a new framework for low incidence countries based on concepts and definitions consistent with those of previous recommendations from WHO/IUATLD Working Groups. In low-incidence countries, a broader spectrum of interventions is available and feasible, including: 1) a general approach to tuberculosis which ensures rapid detection and treatment of all the cases and prevention of unnecessary deaths; 2) an overall control strategy aimed at reducing the incidence of tuberculosis infection (risk-group management and prevention of transmission of infection in institutional settings) and 3) a tuberculosis elimination strategy aimed at reducing the prevalence of tuberculosis infection (outbreak management and provision of preventive therapy for specified groups and individuals). Government and private sector commitment towards elimination, effective case detection among symptomatic individuals together with active case finding in special groups, standard treatment of disease and infection, access to tuberculosis diagnostic and treatment services, prevention (e.g. through screening and bacille Calmette-Guéria immunization in specified groups), surveillance and treatment outcome monitoring are prerequisites to implementing the policy package recommended in this new framework document.

Infliximab is a humanized antibody against tumor necrosis factor alpha (TNF-alpha) that is used in the treatment of Crohn's disease and rheumatoid arthritis. Approximately 147,000 patients throughout the world have received infliximab. Excess TNF-alpha in association with tuberculosis may cause weight loss and night sweats, yet in animal models it has a protective role in the host response to tuberculosis. There is no direct evidence of a protective role of TNF-alpha in patients with tuberculosis.

Does immigration from a high-prevalence area contribute to an increased risk of tuberculosis in a low-incidence country? The tuberculosis incidence in Somalia is among the highest ever registered. Due to civil war and starvation, nearly half of all Somalis have been forced from their homes, causing significant migration to low-incidence countries. In Denmark, two-thirds of all tuberculosis patients are immigrants, half from Somalia. To determine the magnitude of Mycobacterium tuberculosis transmission between Somalis and Danes, we analyzed DNA fingerprint patterns of isolates collected in Denmark from 1992 to 1999, comprising >97% of all culture-positive patients (n = 3,320). Of these, 763 were Somalian immigrants, 55.2% of whom shared identical DNA fingerprint patterns; 74.9% of these were most likely infected before their arrival in Denmark, 23.3% were most likely infected in Denmark by other Somalis, and 1.8% were most likely infected by Danes. In the same period, only 0.9% of all Danish tuberculosis patients were most likely infected by Somalis. The Somalian immigrants in Denmark could be distributed into 35 different clusters with possible active transmission, of which 18 were retrieved among Somalis in the Netherlands. This indicated the existence of some internationally predominant Somalian strains causing clustering less likely to represent recent transmission. In conclusion, M. tuberculosis transmission among Somalis in Denmark is limited, and transmission between Somalis and Danes is nearly nonexistent. The higher transmission rates between nationalities found in the Netherlands do not apply to the situation in Denmark and not necessarily elsewhere, since many different factors may influence the magnitude of active transmission.

The whole-genome fingerprinting technique, fluorescent amplified-fragment length polymorphism (FAFLP) analysis, was applied to Mycobacterium tuberculosis. Sixty-five clinical isolates were analyzed to determine the value of FAFLP as a stand-alone genotyping technique and to compare it with the well-established IS6110 typing system. The genome sequence of M. tuberculosis strain H37Rv (S. T. Cole et al., Nature 393:537-544, 1998) was used to model computer-generated informative primer combination(s), and the precision and reproducibility of FAFLP were evaluated by comparing the results of in vitro and computer-generated experiments. Multiplex FAFLP was used to increase resolving power in a predictable and systematic fashion. FAFLP analysis was broadly congruent with IS6110 typing for those strains with multiple IS6110 copies. It was also able to resolve an epidemiologically unlinked group of strains with only one copy of IS6110; up to 10% of clinical isolates may fall into this category. For certain epidemiological investigations, it was concluded that a combination of FAFLP and IS6110 typing would give higher resolution than would either alone. FAFLP data were digital, precise, reproducible, and suitable for rapid electronic dissemination, manipulation, interlaboratory comparison, and storage in national or international epidemiological databases. Because FAFLP samples and analyzes base substitution across the genome as a whole, FAFLP could generate new information about the microevolution of the M. tuberculosis complex.

To estimate the risk and prevalence of Mycobacterium tuberculosis (MTB) infection and tuberculosis (TB) incidence, prevalence, and mortality, including disease attributable to human immunodeficiency virus (HIV), for 212 countries in 1997.

The present study is based on notified cases of tuberculosis (TB) in the National tbc. register 1972-1996. A decline in Tb incidence was seen from 1972 and until the mid-1980's. Subsequently the trend has reversed due to an increasing number of TB cases in foreigners. In 1996, 60% of all cases of TB in Denmark were found in foreigners reflecting the rising number of refugees and their families arriving in Denmark from highly endemic areas, mainly Somalia. Among native Danes the TB incidence fell from 14 per 100,000 in 1972 to 4 per 100,000 in the 1980's and stabilized at this very low level. The unchanged incidence in Danes covers a falling incidence in the older and a rising incidence in the younger and middle-aged adult population, mainly in the capital. Approximately half of the cases occur in high-risk groups. The TB-epidemic is close to elimination in the indigenous Danish population, but the disease is maintained at a low level probably due to increased patient and doctor delay and resulting microepidemics primarily in high-risk populations.