Utility of interferon-gamma releasing assay for the diagnosis of active tuberculosis in children: A systematic review and meta-analysis

INTRODUCTION

The accurate diagnosis of tuberculosis (TB) in children is essential for its effective management and control. Reliable diagnostic tools that are currently available for identifying TB infection include the in vivo tuberculosis skin test (TST) and ex vivo interferon-gamma release assays (IGRAs). This systematic review and meta-analysis aimed to evaluate the diagnostic accuracy of IGRAs in children.

METHODS

Of the 768 screened studies, 47 met the eligibility criteria. Data from 9065 patients, including 1086 (12.0 %) with confirmed TB, were included in the analysis. The overall quality of the included studies, assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool, was unclear.

RESULTS

The calculated pooled sensitivity and specificity of IGRAs in children were 0.85 (95 % confidence interval [CI]: 0.79-0.89) and 0.94 (95 % CI: 0.88-0.97), respectively. Subpopulation analysis revealed that the sensitivities and specificities were as follows: QuantiFERON tests: 0.83 (95 % CI: 0.74-0.89) and 0.93 (95 % CI: 0.87-0.96), T-SPOT: 0.87 (95 % CI: 0.79-0.91) and 0.99 (95 % CI: 0.85-1.00), IGRAs in children under 15 years: 0.77 (95 % CI: 0.43-0.94) and 0.96 (95 % CI: 0.84-0.97), and IGRAs in children under 5 years: 0.85 (95 % CI: 0.52-0.97) and 0.94 (95 % CI: 0.90-0.99), respectively.

CONCLUSIONS

This study demonstrated that the sensitivity and specificity of the IGRAs in children were moderate and high, respectively. Therefore, the IGRAs may be useful for detecting TB infection in children.

CLINICAL TRIAL REGISTRATION

The review protocol was prospectively registered with the University Hospital Medical Information Network Clinical Trials Registry (UMIN000046737).

Analysis of T-lymphocyte subsets and risk factors in children with tuberculosis

BACKGROUND

Tuberculosis (TB) is not only related to infection but also involves immune factors. This study explores the changes in T-lymphocyte subsets in children with TB who are human immunodeficiency virus (HIV)-negative and examines their relationship using chest computed tomography (CT) scans. Additionally, the study identifies risk factors for severe TB (STB) in children and establishes relevant risk prediction models.

METHODS

We recruited 235 participants between 2018 and 2022, comprising 176 paediatric patients with TB who were HIV-negative and 59 age-matched children with bacterial community-acquired pneumonia (CAP). We quantitatively analysed and compared T-lymphocyte subsets between the two groups and among different types of TB infection. Both univariate and multivariate analyses of clinical and laboratory characteristics were conducted to identify independent risk factors for STB in children and to establish a risk prediction model.

RESULTS

The absolute counts of CD3, CD4 and CD8 T-cells in children with TB infection decreased significantly compared with bacterial CAP. The percentage of CD8 T-cells increased, whereas the percentage of CD4 T-cells did not change significantly. The absolute count of CD3, CD4 and CD8 T-cells in extrapulmonary TB (EPTB) was significantly higher than in extra-respiratory TB, with unchanged subset percentages. According to chest CT lesion classification, CD4 T-cell counts decreased significantly in S3 compared with S1 or S2, with no significant change in CD3 and CD8 T-cell counts and percentages. No significant differences were observed in lymphocyte subset counts and percentages between S1 and S2. Univariate analyses indicated that factors such as age, symptom duration, white blood cell count, platelet count, neutrophil-to-lymphocyte ratio (NLR), erythrocyte sedimentation rate, prealbumin level, albumin level, globulin level, albumin/globulin (A/G) ratio, high-sensitivity C-reactive protein (Hs-CRP) level and CD4 and CD8 T-cell counts are associated with STB. Multivariate logistic regression analysis revealed that age, Hs-CRP level, NLR, symptom duration and A/G ratio are independent risk factors for STB in children. Increased age, Hs-CRP levels and NLR, along with decreased A/G, correlate with increased susceptibility to STB. A nomogram model, based on these independent risk factors, demonstrated an area under the receiver operating characteristics curve of 0.867 (95% CI: 0.813-0.921). Internal verification confirmed the model's accuracy, with the calibration curve approaching the ideal and the Hosmer-Lemeshow goodness-of-fit test showing consistent results (χ2 = 12.212, p = 0.142).

CONCLUSION

In paediatric patients with TB, the absolute counts of all lymphocyte subsets were considerably reduced compared with those in patients with bacterial CAP. Clinicians should consider the possibility of EPTB infection in addition to respiratory infections in children with TB who have higher CD3, CD4 and CD8 T-cell counts than the ERTB group. Furthermore, CD4 T-cell counts correlated closely with the severity of chest CT lesions. Age, symptom duration, A/G ratio, Hs-CRP level and NLR were established as independent risk factors for STB. The nomogram model, based on these factors, offers effective discrimination and calibration in predicting STB in children.

Implementing a continuous quality-improvement framework for tuberculosis infection prevention and control in healthcare facilities in China, 2017-2019

BACKGROUND

Tuberculosis (TB) infection prevention and control (IPC) in healthcare facilities is key to reducing transmission risk. A framework for systematically improving TB IPC through training and mentorship was implemented in 9 healthcare facilities in China from 2017 to 2019.

METHODS

Facilities conducted standardized TB IPC assessments at baseline and quarterly thereafter for 18 months. Facility-based performance was assessed using quantifiable indicators for IPC core components and administrative, environmental, and respiratory protection controls, and as a composite of all control types We calculated the percentage changes in scores over time and differences by IPC control type and facility characteristics.

RESULTS

Scores for IPC core components increased by 72% during follow-up when averaged across facilities. The percentage changes for administrative, environmental, and respiratory protection controls were 39%, 46%, and 30%, respectively. Composite scores were 45% higher after the intervention. Overall, scores increased most during the first 6 months. There was no association between IPC implementation and provincial economic development or volume of TB services.

CONCLUSIONS

TB IPC policies and practices showed most improvement early during implementation and did not differ consistently by facility characteristics. The training component of the project helped increase the capacity of healthcare professionals to manage TB transmission risks. Lessons learned here will inform national TB IPC guidance.

Lysosomal enzymes and the oxygen burst capability of monocyte-derived macrophages in active drug-resistant tuberculosis patients in relation to cell attachment

Drug resistance to tuberculosis (TB) has become an obstacle in eliminating tuberculosis. The transmission of drug-resistant TB from patients increases the incidence of primary drug-resistant (DR) TB in individuals who are in close contact. Therefore, it is necessary to incorporate an immunological approach into preventive therapy. This study focuses on the activity of lysosomal enzymes, oxygen bursts, and the attachment ability of macrophages among individuals diagnosed with active drug-resistant TB compared with close contacts with latent TB or healthy cases. We measured macrophage oxygen burst ability (Water-soluble tetrazolium salt (WST) test, Nitric Oxide production, and myeloperoxidase activity) and the degradative ability of lysosomes (activity of the β-glucuronidase and acid phosphatase enzymes). Six active DR-TB patients and 18 close-contact cases (8 Latent Tuberculosis Infection (LTBI); 10 healthy) were recruited at Universitas Indonesia Hospital. The macrophage attachment of the LTBI group was higher than in the other groups. NO production, myeloperoxidase activity, β-glucuronidase, and acid phosphatase were higher in the active DR-TB group. A negative correlation was uncovered between phagocytosis and NO production, myeloperoxidase activity, and lysosomal enzymes. The difference in macrophage function is expected to be a further reference in active DR-TB treatment or preventive therapy.

A systematic review and meta-analysis of circulating serum and plasma microRNAs in TB diagnosis

BACKGROUND

Tuberculosis (TB) ranks as the second leading cause of death globally among all infectious diseases. This problem is likely due to the lack of biomarkers to differentiate the heterogeneous spectrum of infection. Therefore, the first step in solving this problem is to identify biomarkers to distinguish the different disease states of an individual and treat them accordingly. Circulating microRNA (miRNA) biomarkers are promising candidates for various diseases. In fact, we are yet to conceptualize how miRNA expression influences and predicts TB disease outcomes. Thus, this systematic review and meta-analysis aimed to assess the diagnostic efficacy of circulating miRNAs in Latent TB (LTB) and Active Pulmonary TB (PTB).

METHODS

Literature published between 2012 and 2021 was retrieved from PubMed, Web of Science, Cochrane, Scopus, Embase, and Google Scholar. Articles were screened based on inclusion and exclusion criteria, and their quality was assessed using the QUADAS-2 tool. Funnel plots and forest plots were generated to assess the likelihood of study bias and heterogeneity, respectively.

RESULTS

After the screening process, seven articles were selected for qualitative analysis. The study groups, which consisted of Healthy Control (HC) vs. TB and LTB vs. TB, exhibited an overall sensitivity of 81.9% (95% CI: 74.2, 87.7) and specificity of 68.3% (95% CI: 57.8, 77.2), respectively. However, our meta-analysis results highlighted two potentially valuable miRNA candidates, miR-197 and miR-144, for discriminating TB from HC. The miRNA signature model (miR197-3p, miR-let-7e-5p, and miR-223-3p) has also been shown to diagnose DR-TB with a sensitivity of 100%, but with a compromised specificity of only 75%.

CONCLUSION

miRNA biomarkers show a promising future for TB diagnostics. Further multicentre studies without biases are required to identify clinically valid biomarkers for different states of the TB disease spectrum.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO (CRD42022302729).

Gendered gaps to tuberculosis prevention and care in Kenya: a political economy analysis study

BACKGROUND

Tuberculosis (TB) remains a public health concern in Kenya despite the massive global efforts towards ending TB. The impediments to TB prevention and care efforts include poor health systems, resource limitations and other sociopolitical contexts that inform policy and implementation. Notably, TB cases are much higher in men than women. Therefore, the political economy analysis (PEA) study provides in-depth contexts and understanding of the gender gaps to access and successful treatment for TB infection.

DESIGN

PEA adopts a qualitative, in-depth approach through key informant interviews (KII) and documentary analysis.

SETTING AND PARTICIPANTS

The KIIs were distributed among government entities, academia, non-state actors and community TB groups from Kenya.

RESULTS

The themes identified were mapped onto the applied PEA analysis framework domains. The contextual and institutional issues included gender concerns related to the disconnect between TB policies and gender inclusion aspects, such as low prioritisation for TB programmes, limited use of evidence to inform decisions and poor health system structures. The broad barriers influencing the social contexts for TB programmes were social stigma and cultural norms such as traditional interventions that negatively impact health-seeking behaviours. The themes around the economic situation were poverty and unemployment, food insecurity and malnutrition. The political context centred around the systemic and governance gaps in the health system from the national and devolved health functions.

CONCLUSION

Broad contextual factors identified from the PEA widen the disparity in targeted gender efforts toward men. Following the development of effective TB policies and strategies, it is essential to have well-planned gendered responsive interventions with a clear implementation plan and monitoring system to enhance access to TB prevention and care.

Detection of Mycobacterium tuberculosis DNA in CD34+ peripheral blood mononuclear cells of adults with tuberculosis infection and disease

OBJECTIVES

To investigate whether Mycobacterium tuberculosis (Mtb) DNA is detected in peripheral blood mononuclear cells (PBMC) of subjects with tuberculosis (TB) or TB infection (TBI) living in a low-burden country.

METHODS

We prospectively enrolled 57 patients with TB, 41 subjects with TBI, and 39 controls in Rome, Italy. PBMC were isolated, cluster of differentiation (CD)34+ and CD34- cells were immunomagnetic separated, DNA was extracted, and digital polymerase chain reaction for IS6110 and rpoB sequences was used to detect Mtb DNA in PBMC subsets and unfractionated PBMC.

RESULTS

We detected Mtb DNA at a low copy number in CD34+ cells in 4o f 30 (13%) patients with TB, 2 of 24 (8%) subjects with TBI, and 1 of 24 (4%) controls. Mtb DNA was detected in unfractionated PBMC in 3 of 51 (6%) patients with TB, 2 of 38 (5%) subjects with TBI, and 2 of 36 (6%) controls. In CD34- cells, only 1 of 31 (3%) subjects with TBI tested positive for Mtb DNA.

CONCLUSIONS

Mtb DNA was detected at low frequencies and levels in the PBMC of subjects with TBI and donors with TB living in a low-burden country. In particular, Mtb DNA was detected more frequently in CD34+ cells, supporting the hypothesis that these cells may represent a Mtb niche. This finding informs biological understanding of Mtb pathogenesis and may support the development of a microbial blood biomarker for Mtb infection.

State-of-the-art detection of Mycobacterium tuberculosis in blood during tuberculosis infection using phage technology

Tuberculosis (TB), an aerosol-transmitted infection caused by Mycobacterium tuberculosis (Mtb), remains the commonest cause of death globally, from an infectious bacterial disease. Nine years on from the launch of the World Health Organization (WHO)'s END-TB strategy, disease incidence rates are stubbornly unchanged [1]. While this represents, in part, a reversal of improving trends caused by the COVID-19 pandemic, it also reflects the fragility and inadequacy of healthcare systems to sustain TB control [2]. Although multifactorial, a key reason for this is the ineffectiveness of existing clinical tools to meet the two key objectives of the END-TB strategy-(i) early diagnosis and treatment of TB disease (to limit onward transmission); and (ii) disease prevention through screening for asymptomatic TB infection (TBI). Meeting both objectives will rely on the development of new biomarkers with high accuracy, but the global nature of the TB problem also requires that new tests are rapid, low cost and can be measured in patients by sampling from universally accessible sites. In this review, we will present the accumulating evidence for circulating Mtb in both TB disease and asymptomatic TBI and discuss the potential utility of novel bacteriophage-based technology for blood-based detection of Mtb.

In silico agent-based modeling approach to characterize multiple in vitro tuberculosis infection models

In vitro models of Mycobacterium tuberculosis (Mtb) infection are a valuable tool for examining host-pathogen interactions and screening drugs. With the development of more complex in vitro models, there is a need for tools to help analyze and integrate data from these models. To this end, we introduce an agent-based model (ABM) representation of the interactions between immune cells and bacteria in an in vitro setting. This in silico model was used to simulate both traditional and spheroid cell culture models by changing the movement rules and initial spatial layout of the cells in accordance with the respective in vitro models. The traditional and spheroid simulations were calibrated to published experimental data in a paired manner, by using the same parameters in both simulations. Within the calibrated simulations, heterogeneous outputs are seen for bacterial count and T cell infiltration into the macrophage core of the spheroid. The simulations also predict that equivalent numbers of activated macrophages do not necessarily result in similar bacterial reductions; that host immune responses can control bacterial growth in both spheroid structure dependent and independent manners; that STAT1 activation is the limiting step in macrophage activation in spheroids; and that drug screening and macrophage activation studies could have different outcomes depending on the in vitro culture used. Future model iterations will be guided by the limitations of the current model, specifically which parts of the output space were harder to reach. This ABM can be used to represent more in vitro Mtb infection models due to its flexible structure, thereby accelerating in vitro discoveries.

Impact of delayed diagnosis and treatment on tuberculosis infection within families: A case report

BACKGROUND

A 32-year-old male patient was diagnosed with a 30% left pneumothorax on November 5, 2020, during which chest imaging indicated abnormalities. Despite this, pulmonary tuberculosis (TB) was not diagnosed or treated at that time due to a negative result in the MGIT960 culture. The patient experienced symptoms of cough and expectoration on April 24, 2022. Upon repeating the chest imaging, the condition had worsened, confirming the presence of pulmonary TB, leading to the patient's hospitalization. On September 1, 2022, the 11-year-old daughter of the patient was diagnosed with pulmonary tuberculosis accompanied by bronchial tuberculosis and tuberculous pleurisy.

METHODS

The diagnosis of pulmonary tuberculosis was confirmed through sputum smears and Gene Xpert MTB/RIF testing, for the patient and his 11-year-old daughter in 2022. The patient underwent a 6-month combination therapy (2HRZE/4HR) comprising isoniazid, rifampicin, pyrazinamide, and ethambutol. His daughter with pulmonary tuberculosis accompanied by bronchial tuberculosis and tuberculous pleurisy underwent a 12-month combination therapy.

RESULTS

Late diagnosis and treatment delays contribute to tuberculosis infections within families. Fortunately, after more than 3 months of antituberculosis treatment, the patient experienced relief from cough and sputum secretion, and there was improvement observed in the chest CT scan. Six months later, the patient was successfully cured of TB. 12 months later, his daughter also was successfully cured of TB.

CONCLUSION SUBSECTIONS

Early diagnosis and treatment of tuberculosis (TB) is vital to reduce transmission, morbidity, and mortality.

Tuberculosis infection and hypertension: prevalence estimates from the US National Health and Nutrition Examination Survey

OBJECTIVES

Tuberculosis infection (TBI) is marked by dynamic host-pathogen interactions with persistent low-grade inflammation and is associated with increased risk of cardiovascular diseases (CVD) including acute coronary syndrome, myocardial infarction and stroke. However, few studies assess the relationship between TBI and hypertension, an intermediate of CVD. We sought to determine the association between TBI and hypertension using data representative of the adult US population.

METHODS

We performed cross-sectional analyses using data from the 2011-2012 US National Health and Nutrition Examination Survey (NHANES). Eligible participants included adults with valid QuantiFERON-TB Gold In-Tube (QFT-GIT) test results who also had blood pressure measures and no history of TB disease. TBI was defined by a positive QFT-GIT. We defined hypertension by either elevated measured blood pressure levels (ie, systolic ≥130 mm Hg or diastolic ≥80 mm Hg) or known hypertension indications (ie, self-reported previous diagnosis or use of antihypertensive medications). Analyses were performed using robust quasi-Poisson regressions and accounted for the stratified probability sampling design of NHANES.

RESULTS

The overall prevalence of TBI was 5.7% (95% CI 4.7% to 6.7%) and hypertension was present among 48.9% (95% CI 45.2% to 52.7%) of participants. The prevalence of hypertension was higher among those with TBI (58.5%, 95% CI 52.4% to 64.5%) than those without TBI (48.3%, 95% CI 44.5% to 52.1%) (prevalence ratio (PR) 1.2, 95% CI 1.1 to 1.3). However, after adjusting for confounders, the prevalence of hypertension was similar for those with and without TBI (adjusted PR 1.0, 95% CI 1.0 to 1.1). The unadjusted prevalence of hypertension was higher among those with TBI versus no TBI, especially among individuals without CVD risk factors including those with normal body mass index (PR 1.6, 95% CI 1.2 to 2.0), euglycaemia (PR 1.3, 95% CI 1.1 to 1.5) or non-smokers (PR 1.2, 95% CI 1.1 to 1.4).

CONCLUSIONS

More than half of adults with TBI in the USA had hypertension. Importantly, we observed a relationship between TBI and hypertension among those without established CVD risk factors.

SUMMARY

The prevalence of hypertension was high (59%) among adults with TBI in the USA. In addition, we found that the prevalence of hypertension was significantly higher among adults with positive QFT without established hypertension risk factors.

TB index case tracing in the Roma community in the Czech Republic

Tuberculosis (TB) contact tracing and TB preventive treatment are key tools in preventing the transmission of TB with the aim of eliminating the disease. Our study seeks to demonstrate how the infection spread from an individual patient to the entire community and how proactive contact tracing facilitated prompt diagnosis and treatment. Our work was conducted as a retrospective analysis of the spread of TB infection within the Roma community in the Czech Republic, following the case of an index patient who succumbed to pulmonary TB. Several levels of care and preventive and treatment measures are outlined. Confirming the identity of the Mycobacterium tuberculosis strain was achieved using molecular methods. Among the 39 individuals examined, TB disease was detected in eight patients and TB infection was detected in six patients. The investigation of contacts within this group yielded positive results in 36% of cases, necessitating treatment. The study's findings provide evidence that actively tracing individuals at risk can lead to early detection of cases, prompt treatment, and prevention of further disease transmission. The study also indicates that the highest risk of infection occurs within the sick person's household and that young children under the age of 5 are most susceptible to falling ill.

Antigen-specific chemokine profiles as biomarkers for detecting Mycobacterium tuberculosis infection

Background

Latent tuberculosis (TB) infection can progress to active TB, which perpetuates community transmission that undermines global TB control efforts. Clinically, interferon-γ release assays (IGRAs) are commonly used for active TB case detection. However, low IGRA sensitivity rates lead to false-negative results for a high proportion of active TB cases, thus highlighting IGRA ineffectiveness in differentiating MTB-infected individuals from healthy individuals.

Methods

Participants enrolled at Beijing Chest Hospital from May 2020-April 2022 were assigned to healthy control (HC), LTBI, IGRA-positive TB, and IGRA-negative TB groups. Screening cohort MTB antigen-specific blood plasma chemokine concentrations were measured using Luminex xMAP assays then were verified via testing of validation cohort samples.

Results

A total of 302 individuals meeting study inclusion criteria were assigned to screening and validation cohorts. Testing revealed significant differences in blood plasma levels of CXCL9, CXCL10, CXCL16, CXCL21, CCL1, CCL19, CCL27, TNF-α, and IL-4 between IGRA-negative TB and HC groups. Levels of CXCL9, CXCL10, IL-2, and CCL8 biomarkers were predictive for active TB, as reflected by AUC values of ≥0.9. CXCL9-based enzyme-linked immunosorbent assay sensitivity and specificity rates were 95.9% (95%CI: 91.7-98.3) and 100.0% (92.7-100.0), respectively. Statistically similar AUC values were obtained for CXCL9 and CXCL9-CXCL10 assays, thus demonstrating that combined analysis of CXCL10 and CXCL9 levels did not improve active TB diagnostic performance.

Conclusion

The MTB antigen stimulation-based CXCL9 assay may compensate for low IGRA diagnostic accuracy when used to diagnose IGRA-negative active TB cases and thus is an accurate and sensitive alternative to IGRAs for detecting MTB infection.

Mycobacterium bovis infection of the appendix: a case of appendiceal tuberculosis in rural England

Appendiceal tuberculosis is a rare mimic of acute appendicitis, demonstrated by several case reports of patients from tuberculosis endemic countries. On literature review, there are few cases reported of appendiceal tuberculosis in urban England, and no reports from rural England. This case describes a patient with primary appendiceal tuberculosis from a remote district hospital in England who underwent a diagnostic laparoscopy for suspected acute appendicitis. Intraoperatively, an abnormal appearance with extensive intra-abdominal adhesions was seen in addition to appendicitis, making the diagnosis dubious. Histology of the appendix was positive for acid-fast bacilli and culture of the intra-abdominal fluid revealed a diagnosis of Mycobacterium bovis infection. The mode of infection was thought to be reactivation of latent bovine tuberculosis from drinking unpasteurised milk in adolescence. Taking a focused history, particularly in those with a farming background, and intraoperative sampling for histology and culture are vital in the diagnosis of appendiceal tuberculosis.

IGRA-based INH regimen for prevention of active tuberculosis after kidney transplantation: A single-centre retrospective study

OBJECTIVES

To evaluate the effectiveness and safety of Interferon-gamma release Assay (IGRA)-based isoniazid (INH) prophylaxis strategy to prevent tuberculosis (TB) infection in kidney transplantation (KT) with a risk of TB occurrence.

METHODS

Adult KT recipients (KTRs) between June 2014 and July 2021 were retrospectively enrolled. The development of active TB after KT was evaluated.

RESULTS

Of 925 KTRs, 111 (12.0%) developed active TB. Among the 501 KTRs at a risk of TB occurrence, 70 (14.0%) patients developed active TB, while 41 (9.7%) of 424 patients without risk factors developed active TB (P = 0.05). Two hundred thirty-nine KTRs received IGRA test with 62 (25.9%) were positive. None of IGRA positive patients (0/40) receiving INH prophylaxis developed active TB, whereas 8 out of 22 patients who had positive IGRA results without INH prophylaxis developed active TB (0 vs. 36.4%, P < 0.01). Of note, for those in risk group but with negative IGRA result, no active TB was found even without INH prophylaxis. Although alanine aminotransferase and aspartate aminotransferase in INH prevention group were higher than those before treatment, they did not exceed three-fold of limit of reference range.

CONCLUSIONS

IGRA-based INH treatment is an effective and safe protocol to prevent the development of active TB in KTRs.

Pediatric Tuberculosis Infection Care Facilitators and Barriers: A Qualitative Study

BACKGROUND

A total of 700 000 US children and adolescents are estimated to have latent tuberculosis (TB) infection. Identifying facilitators and barriers to engaging in TB infection care is critical to preventing pediatric TB disease. We explored families' and clinicians' perspectives on pediatric TB infection diagnosis and care.

METHODS

We conducted individual interviews and small group discussions with primary care and subspecialty clinicians, and individual interviews with caregivers of children diagnosed with TB infection. We sought to elicit facilitators and barriers to TB infection care engagement. We used applied thematic analysis to elucidate themes relating to care engagement, and organized themes using a cascade-grounded pediatric TB infection care engagement framework.

RESULTS

We enrolled 19 caregivers and 24 clinicians. Key themes pertaining to facilitators and barriers to care emerged that variably affected engagement at different steps of care. Clinic and health system themes included the application of risk identification strategies and communication of risk; care ecosystem accessibility; programs to reduce cost-related barriers; and medication adherence support. Patient- and family-level themes included TB knowledge and beliefs; trust in clinicians, tests, and medical institutions; behavioral skills; child development and parenting; and family resources.

CONCLUSIONS

Risk identification, education techniques, trust, family resources, TB stigma, and care ecosystem accessibility enabled or impeded care cascade engagement. Our results delineate an integrated pediatric TB infection care engagement framework that can inform multilevel interventions to improve retention in the pediatric TB infection care cascade.

IgG glycosylation associates with risk of progression from latent to active tuberculosis

OBJECTIVES

Glycosylation motifs shape antibody structure, stability and antigen affinity and play an important role in antibody localization and function. Serum IgG glycosylation profiles are significantly altered in infectious diseases, including tuberculosis (TB), but have not been studied in the context of progression from latent to active TB.

METHODS

We performed a longitudinal study of paired bulk IgG glycosylation and transcriptomic profiling in blood from individuals with active TB (ATB) or latent TB infection (LTBI) before and after treatment.

RESULTS

We identified that a combination of two IgG1 glycosylation traits were sufficient to distinguish ATB from LTBI with high specificity and sensitivity, prior to, and after treatment. Importantly, these two features positively correlated with previously defined cellular and RNA signatures of ATB risk in LTBI, namely monocyte to lymphocyte ratio and the expression of interferon (IFN)-associated gene signature of progression (IFN-risk signature) in blood prior to treatment. Additional glycosylation features at higher prevalence in LTBI individuals with high expression of the IFN-risk signature prior to treatment included fucosylation on IgG1, IgG2 and IgG3.

CONCLUSIONS

Together, our results demonstrate that bulk IgG glycosylation features could be useful in stratifying the risk of LTBI reactivation and progression to ATB.

Assistance of next-generation sequencing for diagnosis of disseminated Bacillus Calmette-Guerin disease with X-SCID in an infant: a case report and literature review

Bacille Calmette-Guérin (BCG) is a live strain of Mycobacterium bovis (M.bovis) for use as an attenuated vaccine to prevent tuberculosis (TB) infection, while it could also lead to an infection in immunodeficient patients. M.bovis could infect patients with immunodeficiency via BCG vaccination. Disseminated BCG disease (BCGosis) is extremely rare and has a high mortality rate. This article presents a case of a 3-month-old patient with disseminated BCG infection who was initially diagnosed with hemophagocytic syndrome (HPS) and eventually found to have X-linked severe combined immunodeficiency (X-SCID). M.bovis and its drug resistance genes were identified by metagenomics next-generation sequencing (mNGS) combined with targeted next-generation sequencing (tNGS) in blood and cerebrospinal fluid. Whole exome sequencing (WES) revealed a pathogenic variant in the common γ-chain gene (IL2RG), confirming X-SCID. Finally, antituberculosis therapy and umbilical cord blood transplantation were given to the patient. He was successfully cured of BCGosis, and his immune function was restored. The mNGS combined with the tNGS provided effective methods for diagnosing rare BCG infections in children. Their combined application significantly improved the sensitivity and specificity of the detection of M.bovis.

Identification of Chemical Scaffolds Targeting Drug-Resistant and Latent Mycobacterium tuberculosis through High-Throughput Whole-Cell Screening

Identification of structurally unique chemical entities targeting unexplored bacterial targets is a prerequisite to combat increasing drug resistance against Mycobacterium tuberculosis. This study employed a whole-cell screening approach as an initial filter to scrutinize a 10,000-compound chemical library, resulting in the discovery of seven potent compounds with MIC values ranging from 1.56 to 25 μM. These compounds were categorized into four distinct chemical groups. Remarkably, they demonstrated efficacy against drug-resistant and nonreplicating tuberculosis strains, highlighting their effectiveness across different infection states. With a favorable selectivity index (>10), these compounds showed a safe therapeutic range and exhibited potency in an intracellular model of Mtb infection, mimicking the in vivo setup. Combining these identified hits with established anti-TB drugs revealed additive effects with rifampicin, isoniazid, and bedaquiline. Notably, IIIM-IDD-01 exhibited synergy with isoniazid and bedaquiline, likely due to their complementary mechanisms of targeting Mtb. Most potent hits, IIIM-IDD-01 and IIIM-IDD-02, displayed time- and concentration-dependent killing of Mtb. Mechanistic insights were sought through SEM and docking studies, although comprehensive evaluation is ongoing to unravel the hits' specific targets and modes of action. The hits demonstrated favorable pharmacokinetic properties (ADME-Tox) and showed a low risk of adverse effects, along with a predicted high level of oral bioavailability. These promising hits can serve as an initial basis for subsequent medicinal chemistry endeavors aimed at developing a new series of anti-TB agents. Moreover, the study affirms the significance of high-throughput in vitro assays for the TB drug discovery. It also emphasizes the necessity of targeting diverse TB strains to address the heterogeneity of tuberculosis bacteria.

Completion of isoniazid preventive therapy for latent tuberculosis infection among children and adolescents compared to adults living with HIV in Kinshasa, Democratic Republic of the Congo

BACKGROUND

Little is known about isoniazid preventive therapy (IPT) completion rates among children or adolescents compared to adults living with HIV in Kinshasa, Democratic Republic of the Congo (DRC).

METHODS

We conducted a retrospective cohort analysis including children, adolescents, and adults living with HIV who were treated at FHI360 and partners-implemented HIV care programs at six health zones in Kinshasa, DRC, from 2004 to 2020. The primary outcome was the proportion of children, adolescents versus adults who did complete 6 months of daily self-administered IPT. Log-binomial regression assessed independent predictors of IPT non-completion and Kaplan-Meier technique for survival analysis.

RESULTS

Of 11,691 eligible patients on ART who initiated IPT, 429 were children (<11 years), 804 adolescents (11-19 years), and 10,458 adults (≥20 years). The median age was 7 (IQR: 3-9) years for children, 15 (IQR: 13-17) years for adolescents, and 43 (35-51) years for adults. Among those who were initiated on IPT, 5625 out of 11,691 people living with HIV (PLHIV) had IPT completion outcome results, and an overall 3457/5625 (61.5%) completion rate was documented. Compared to adults, children and adolescents were less likely to complete IPT [104/199 (52.3%) and 268/525 (51.0%), respectively, vs. 3085/4901 (62.9%)]. After adjustment, the only independent predictors for IPT non-completion were health zone of residence and type of ART regimen. Kaplan-Meier analysis showed comparable poor survival among patients who completed IPT versus those who did not (p-value for log-rank test, 0.15).

CONCLUSIONS

The overall sub-optimal IPT completion rate in adults as well as children/adolescents in this setting is of great concern. Prospective studies are needed to elucidate the specific barriers to IPT completion among children, adolescents, and adults in DRC as well as the scale-up of evidence-informed interventions to improve IPT completion, such as adoption of shorter TB preventive regimens.

Pregnancy Outcomes in Women Screened for Tuberculosis Infection in Swedish Antenatal Care

BACKGROUND

Tuberculosis (TB) disease has been associated with pregnancy complications. However, the potential impact of TB infection (TBI) on pregnancy outcome is unknown. To investigate this, we conducted a register-based study in immigrant women screened with QuantiFERON assays for TBI in antenatal care in Sweden.

METHODS

Women with history of immigration from TB-endemic countries were eligible for inclusion if national identification numbers and available QuantiFERON results obtained during pregnancy from 2014 to 2018 were available. QuantiFERON results were linked to data on maternal characteristics and pregnancy outcomes from the national Pregnancy and Patient Registers. TBI was defined as nil-corrected QuantiFERON result ≥0.35 IU/mL, in the absence of TB disease. Pregnancies in women with TB disease or human immunodeficiency virus were excluded, as were multiplex pregnancies, pregnancies resulting in miscarriage, and pregnancies occurring >10 years after immigration. Odds of defined adverse pregnancy outcomes were compared by maternal TBI status using mixed effects logistic regression with adjustment for maternal age and region of origin.

RESULTS

In total, 7408 women with 12 443 pregnancies were included. In multivariable analysis, stillbirth (adjusted odds ratio [AOR], 1.90; 95% confidence interval [CI], 1.13-3.21; P = .016), severe preeclampsia (AOR, 1.62; 95% CI, 1.03-2.56; P = .036), low birthweight (<2500 g; AOR, 1.38; 95% CI, 1.01-1.88; P = .041), and emergency cesarean section (AOR, 1.28; 95% CI, 1.02-1.63; P = .033) were significantly associated with TBI.

CONCLUSIONS

Among immigrant women seeking antenatal care in Sweden, TBI was independently associated with adverse pregnancy outcomes. Further studies are needed to corroborate these findings and to explore mechanisms involved.

An investigation of the effects of meteorological factors on the incidence of tuberculosis

To explore the influence of meteorological factors on the incidence of tuberculosis (TB) in Yingjisha County, Kashgar Region, Xinjiang, and to provide a scientific basis for the prevention and control of TB. The Spearman correlation analysis and distribution lag nonlinear model analysis were conducted on the number of daily reported cases of TB from 2016 to 2023 to study the association effect of various meteorological factors and the daily incidence number of TB in Yingjisha County. A total of 13,288 TB cases were reported from January 2016 to June 2023, and June to October is the peak period of annual TB incidence. Spearman correlation analysis revealed that average daily temperature (AT) and average daily wind speed (WS) were positively correlated with TB incidence (rAT = 0.110, rWS = 0.090); and average daily relative humidity (RH) and TB incidence was negatively correlated (rRH = - 0.093). When AT was - 15 °C, the RR reached a maximum of 2.20 (95% CI: 0.77-6.29) at a lag of 21 days. When RH was 92%, the RR reached a maximum of 1.05 (95% CI: 0.92-1.19) at a lag of 6 days. When WS was 5.2 m/s, the RR reached a maximum of 1.30 (95% CI: 0.78-2.16) at a lag of 16 days. There is a non-linearity and a certain lag between meteorological factors and the occurrence and prevalence of TB in the population, which is mainly manifested in the fact that the risk of incidence of TB decreases with the increase of the daily AT, has a hazardous effect within a certain range of humidity as the average daily RH rises, and gradually increases with the increase of the average daily WS. Local residents are advised to pay attention to climate change so as to take appropriate preventive measures, especially women and middle and old age group should pay close attention to climate change and add more clothes in time, minimise travelling in hazy weather and windy and sandy weather, maintain good nutrition, adequate sleep and moderate exercise in daily life to enhance their immunity, wash hands frequently and ventilate the air, and try to avoid staying in humid and confined spaces in order to reduce the risk of latent TB patients developing the disease.

Tuberculosis in Sudan: systematic review and meta analysis

Every year, 10 million people fall ill with tuberculosis (TB). Despite being a preventable and curable disease, 1.5 million people die from TB each year -making it the world's top infectious disease. TB is the leading cause of death of people with HIV and also a major contributor to antimicrobial resistance. Its presumed that TB was the cause of 1% of the total deaths among inpatients in Sudan in 2017. The current study is aimed to provide pooled prevalence of Mycobacterium tuberculosis among Sudanese as well as to determine any socio-cultural risk factors associated. A systematic review of the literature was conducted and regulated in accordance with the PRISMA Statement. After abstract and full text screening only twenty-six articles met our inclusion criteria and passed the quality assessment procedure. Pulmonary tuberculosis prevalence was assessed in sixteen included studies among participants from Khartoum, Gezira, Kassala, Blue Nile, River Nile, White Nile, Gadarif, Red sea, North Kordofan, Northern State, Sennar and West Darfur States, representing a total sample size of 11,253 participants of suspected individuals such as febrile outpatients, TB patients' contacts and other groups such as HIV/AIDS patients, hemodialysis patients, School adolescents as well as pregnant women. The pooled prevalence was 30.72% [CI: 30.64, 30.81]. Moreover, Khartoum State recorded the highest pooled prevalence as 41.86% [CI: 14.69, 69.02] based on a total sample size of 2,737 participants. Furthermore, male gender and rural residence were found to be significantly associated with TB infection. Further research with larger sample sizes targeting prevalence and risk factors of TB among Sudanese population is needed to be conducted.

Financial burden of tuberculosis diagnosis and treatment for patients in Ethiopia: a systematic review and meta-analysis

BACKGROUND

Despite the diagnosis and treatment of tuberculosis (TB) given free of charge in many high-burden countries, the costs that patients face in the cascade of care remain a major concern. Here, we aimed to investigate the financial burden of TB diagnosis and treatment for people with TB in Ethiopia.

METHOD

For this systematic review and meta-analysis, we searched PubMed/MEDLINE, Embase, and Cochrane Center for Clinical Trials from December 1 2022 to 31 June 2023 for articles reporting the cost of diagnosis and treatment for patients regardless of their age with all forms of TB in Ethiopia. Major study outcomes were catastrophic costs, direct (out-of-pocket) pre-diagnosis, medical cost, and post-diagnosis costs, indirect (income loss) costs, coping costs, and total costs. We have used a threshold of 20% to define catastrophic costs. We used random-effects meta-analyses to calculate summary estimates of costs. R-studio software was used for analysis. The study is registered with PROSPERO: CRD42023387687.

RESULT

Twelve studies, with a total of 4792 patients with TB, were included in our analysis. At the 20% threshold of total expenses, 51% of patients (2301 participants from 5 studies, 95% CI: 36-65%, I2 = 97%) faced catastrophic costs due to bacteriologically confirmed drug-sensitive pulmonary TB. Private facility diagnosis, drug-resistance TB, TB-HIV co-infection, hospitalization, and occupation were found to be associated with catastrophic costs. Reduction in the total cost spent by the patients was associated with digital adherence interventions, community-based direct observed therapy, short-course MDR-TB treatment regimens, and active case-finding. Pre-diagnosis costs had a positive correlation with diagnosis delays and the number of facilities visited until diagnosis. Post-diagnosis costs had a positive correlation with rural residence and inpatient treatments.

CONCLUSION

Irrespective of a national policy of free TB service, more than half of TB patients are suffering catastrophic costs due to drug-sensitive pulmonary TB in Ethiopia and most of the patients spend a lot of money during the pre-diagnosis period and intensive phase, but declined drastically over time. Active case-finding, digital adherence interventions, community-based treatment, and comprehensive health insurance coverage have the potential to minimize the financial burden of TB diagnosis and treatment.

Identification of apoptosis-related gene signatures as potential biomarkers for differentiating active from latent tuberculosis via bioinformatics analysis

Background

Apoptosis is associated with the pathogenesis of Mycobacterium tuberculosis infection. This study aims to identify apoptosis-related genes as biomarkers for differentiating active tuberculosis (ATB) from latent tuberculosis infection (LTBI).

Methods

The tuberculosis (TB) datasets (GSE19491, GSE62525, and GSE28623) were downloaded from the Gene Expression Omnibus (GEO) database. The diagnostic biomarkers differentiating ATB from LTBI were identified by combining the data of protein-protein interaction network, differentially expressed gene, Weighted Gene Co-Expression Network Analysis (WGCNA), and receiver operating characteristic (ROC) analyses. Machine learning algorithms were employed to validate the diagnostic ability of the biomarkers. Enrichment analysis for biomarkers was established, and potential drugs were predicted. The association between biomarkers and N6-methyladenosine (m6A) or 5-methylated cytosine (m5C) regulators was evaluated.

Results

Six biomarkers including CASP1, TNFSF10, CASP4, CASP5, IFI16, and ATF3 were obtained for differentiating ATB from LTBI. They showed strong diagnostic performances, with area under ROC (AUC) values > 0.7. Enrichment analysis demonstrated that the biomarkers were involved in immune and inflammation responses. Furthermore, 24 drugs, including progesterone and emricasan, were predicted. The correlation analysis revealed that biomarkers were positively correlated with most m6A or m5C regulators.

Conclusion

The six ARGs can serve as effective biomarkers differentiating ATB from LTBI and provide insight into the pathogenesis of Mycobacterium tuberculosis infection.

Multiple cytokine analysis based on QuantiFERON-TB gold plus in different tuberculosis infection status: an exploratory study

BACKGROUND

More efficient and convenient diagnostic method is a desperate need to reduce the burden of tuberculosis (TB). This study explores the multiple cytokines secretion based on QuantiFERON-TB Gold Plus (QFT-Plus), and screens for optimal cytokines with diagnostic potential to differentiate TB infection status.

METHODS

Twenty active tuberculosis (ATB) patients, fifteen patients with latent TB infection (LTBI), ten patients with previous TB and ten healthy controls (HC) were enrolled. Whole blood samples were collected and stimulated by QFT-Plus TB1 and TB2 antigens. The levels of IFN-γ, TNF-α, IL-2, IL-6, IL-5, IL-10, IP-10, IL-1Ra, CXCL-1 and MCP-1 in supernatant were measured by Luminex bead-based multiplex assays. The receiver operating characteristic curve was used to evaluate the diagnostic accuracy of cytokine for distinguishing different TB infection status.

RESULTS

After stimulation with QFT-Plus TB1 and TB2 antigens, the levels of all cytokines, except IL-5 in TB2 tube, in ATB group were significantly higher than that in HC group. The levels of IL-1Ra concurrently showed the equally highest AUC for distinguishing TB infection from HC, followed by the levels of IP-10 in both TB1 tube and TB2 tube. Moreover, IP-10 levels displayed the largest AUC for distinguishing ATB patients from non-ATB patients. Meanwhile, the levels of IP-10 also demonstrated the largest AUC in both TB1 tube and TB2 tube for distinguishing ATB patients from LTBI.

CONCLUSIONS

In addition to conventional detection of IFN-γ, measuring IP-10 and IL-1Ra based on QFT-Plus may have the more tremendous potential to discriminate different TB infection status.

Mucosal and systemic antigen-specific antibody responses correlate with protection against active tuberculosis in nonhuman primates

BACKGROUND

Increasing evidence supports that antibodies can protect against active tuberculosis (TB) but knowledge of potentially protective antigens, especially in the airways, is limited. The main objective of this study was to identify antigen-specific airway and systemic immunoglobulin isotype responses associated with the outcome of controlled latent Mycobacterium tuberculosis (Mtb) infection (LTBI) versus uncontrolled infection (TB) in nonhuman primates.

METHODS

In a case-control design, using non-parametric group comparisons with false discovery rate adjustments, we assessed antibodies in 57 cynomolgus macaques which, following low-dose airway Mtb infection, developed either LTBI or TB. We investigated airway and systemic IgG, IgA, and IgM responses in paired bronchoalveolar lavage and plasma samples prior to, two-, and 5-6-months post Mtb infection using an antigen-unbiased approach with Mtb glycan and proteome-wide microarrays.

FINDINGS

Macaques that developed LTBI (n = 36) had significantly increased airway and plasma IgA reactivities to specific arabinomannan (AM) motifs prior to Mtb infection compared to those that developed TB (n = 21; p < 0.01, q < 0.05). Furthermore, LTBI macaques had higher plasma IgG reactivity to protein MTB32A (Rv0125) early post Mtb infection (p < 0.05) and increasing airway IgG responses to some proteins over time.

INTERPRETATION

Our results support a protective role of pre-existing mucosal (lung) and systemic IgA to specific Mtb glycan motifs, suggesting that prior exposure to nontuberculous mycobacteria could be protective against TB. They further suggest that IgG to Mtb proteins early post infection could provide an additional protective mechanism. These findings could inform TB vaccine development strategies.

FUNDING

NIH/NIAID AI117927, AI146329, and AI127173 to JMA.

Distinct gene expression signatures comparing latent tuberculosis infection with different routes of Bacillus Calmette-Guérin vaccination

Tuberculosis remains an international health threat partly because of limited protection from pulmonary tuberculosis provided by standard intradermal vaccination with Bacillus of Calmette and Guérin (BCG); this may reflect the inability of intradermal vaccination to optimally induce pulmonary immunity. In contrast, respiratory Mycobacterium tuberculosis infection usually results in the immune-mediated bacillary containment of latent tuberculosis infection (LTBI). Here we present RNA-Seq-based assessments of systemic and pulmonary immune cells from LTBI participants and recipients of intradermal and oral BCG. LTBI individuals uniquely display ongoing immune activation and robust CD4 T cell recall responses in blood and lung. Intradermal BCG is associated with robust systemic immunity but only limited pulmonary immunity. Conversely, oral BCG induces limited systemic immunity but distinct pulmonary responses including enhanced inflammasome activation potentially associated with mucosal-associated invariant T cells. Further, IL-9 is identified as a component of systemic immunity in LTBI and intradermal BCG, and pulmonary immunity following oral BCG.

Cost of inaction: a framework to estimate the economic cost of missing a patient with tuberculosis in the Indian context

OBJECTIVES

To estimate the economic impact of failure to find and treat tuberculosis disease and prevent tuberculosis infection from progressing to active disease.

DESIGN

Estimating the economic cost of not finding and treating a patient suffering from tuberculosis.

SETTING

Estimation methodology is developed in the Indian context, as informed by local costs and reported tuberculosis epidemiology.

PARTICIPANTS

No individual participants were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure is the total cost of patients with drug-susceptible and drug-resistant tuberculosis who are and are not found and treated by tuberculosis programmes, including costs for medications, lost productivity, healthcare services and furthered transmission. We calculate the economic burdens by varying the number of individuals a person sick with tuberculosis infects (10 or 15 people) and the risk of progression to tuberculosis disease if infected (5 or 8%). The secondary outcome measure is the amount saved by finding a patient early or who would not have otherwise been found. All costs are presented in US dollars (exchange rate: 72 Indian rupees/1 US$).

RESULTS

By finding and treating a patient early before furthered transmission occurs-or stopping progression of tuberculosis infection to tuberculosis disease with preventive therapy-the Indian health system can save US$5502 to US$15 825 and US$5846 to US$25 575, for each individual with drug-susceptible and drug-resistant tuberculosis, respectively, across scenarios.

CONCLUSIONS

These estimates provide crude, lower bounds for the potential costs of not appropriately diagnosing and treating a single patient with active tuberculosis in a timely manner, or preventing a patient with tuberculosis infection from progressing to active disease. The actual financial burden on society is far higher than estimated using this simple, short-term cost-effective analyses. Our results highlight the limitations of tuberculosis costing models to date, and demonstrate the importance of accounting for airborne transmission of tuberculosis.

Tuberculosis infection control practice and associated factors among health care workers in Ethiopia: Systematic review and meta-analysis

BACKGROUND

The poor practice of tuberculosis infection control may increase the risk of transmission of tuberculosis in healthcare settings. Thus, this study aimed to determine the pooled magnitude of good tuberculosis infection control practice and associated factors among healthcare workers in Ethiopia.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) checklist guideline was followed for this review and meta-analysis. The electronic databases (Pub Med, Cochrane Library, Google scholar and grey literatures) were searched to retrieve articles by using keywords. The Joanna Briggs Institute Meta-Analysis of Statistics Assessment and Review Instrument was used to assess the quality of studies. Heterogeneity was assessed using the I2 statistic. The meta-analysis with a 95% confidence interval using STATA 17 software was computed to present the pooled practice and odds ratio of the determinant factors. Publication bias was assessed visually by inspecting the funnel plot asymmetry and using statistical tests using the eggers and begs test.

RESULTS

Seven studies were included in this meta-analysis, with a total of 3256 health workers. The overall pooled magnitude of good tuberculosis infection control practice was 46.44% (95% CI: 34.21%, 58.67%). In subgroup analysis, the highest practice was in Addis Ababa 51.40% (95% CI: 47.40, 55.40%) and the lowest prevalence of tuberculosis infection control practice was in Amhara region 40.24% (95% CI: 15.46, 65.02%). Working in TB clinics (AOR; 7.42, 95% CI: 3.89, 14.13) and good TB related knowledge (AOR; 4.40, 95% CI: 1.76, 10.97) were the significant predictors of good TB infection control practice.

CONCLUSIONS

Only less than half of the health care workers had good practice of TB infection control. Working in TB clinics and having good TB related knowledge were statistically significant predictors of TB infection control practice. Periodic shifting of health care workers to work in TB clinics and an emphasis on TB infection control related skill based training was recommended to increase the TB infection control practice.

Infections in Asymptomatic Unaccompanied Asylum-seeking Children in London 2016-2022

BACKGROUND

Unaccompanied asylum-seeking children are at increased risk of infections and experience barriers to healthcare access. There is a lack of evidence to underpin existing national and international guidance regarding asymptomatic infection screening in this population. We describe the results from routine infection screening of 1104 unaccompanied asylum-seeking children attending for testing at 3 London centers.

METHODS

We performed a retrospective analysis of routinely collected data from all unaccompanied asylum-seeking children seen in 3 services in London, United Kingdom, between 2016 and 2022.

RESULTS

A total of 1104 unaccompanied asylum-seeking children attended clinic; all accepted screening. The median age was 16 years (range 11-18 years) and 987 (89%) were male. 407 (37%) had at least 1 infection; 116 (11%) had multiple infections. Tuberculosis infection and schistosomiasis were common (found in 18% and 17%, respectively). Hepatitis B infection was identified with a prevalence of 3.9%. Giardia 7.7%, tapeworm 3.3% and Strongyloides 2.8% were also commonly identified.

CONCLUSIONS

We report the largest known dataset to our knowledge of infection screening in asymptomatic unaccompanied asylum-seeking children in Europe to date. This data supports recommendations for routine asymptomatic screening in this high-risk cohort, based on the significant prevalence identified of infections of both personal and public health significance.

[Tuberculosis Infection Control & Hygiene - Recommendations of the DZK]

Preventing the spread of the disease is an essential goal in the care and treatment of tuberculosis. In addition to early diagnosis and effective therapies, isolation of infectious patients and adequate hygiene measures are of particular importance for infection prevention. The present recommendations replace the previous recommendations "tuberculosis infection control" from 2012 and take into account the current national and international recommendations and as well as new scientific findings. After a description of the infection and the transmission pathways, the necessary prevention and hygiene measures in health care facilities are comprehensively presented. Since the last revision of the recommendations on infection prevention, international recommendations and the KRINKO recommendation on ending isolation have been changed. In accordance with this, under certain conditions in the case of sensitive tuberculosis, de-isolation in health care facilities can take place after 14 days without taking the sputum findings into account. The second part of the recommendations explains in detail the measures to be taken in special situations and areas, such as general practitioners, ambulance services and care facilities. Here, the recommendations on respiratory protection have been simplified; for staff, an FFP2 mask is now generally considered sufficient.

Assessing the association between the circulating levels of inflammatory cytokines and the risk of tuberculosis: A bidirectional two-sample mendelian randomization study

BACKGROUND

Numerous observational studies have previously reported an association between inflammatory cytokines and tuberculosis (TB). However, the causal relationship between these factors remains unclear. Consequently, we conducted two-sample Mendelian randomization (MR) analyses to ascertain the causal link between levels of inflammatory cytokines and the risk of TB.

METHODS

Single nucleotide polymorphisms (SNPs) robustly associated with the cytokines, located in or close to their coding gene. SNP was obtained from genome-wide association studies (GWAS) of 8293 individuals of Finnish. TB data was obtained from the UK Biobank, which included 46,293 individuals of European ancestry (comprising 2277 TB cases and 46,056 controls). Two-sample, bi-directional MR analyses using inverse-variance weighted (IVW) method as the primary analysis. Followed by comprehensive sensitivity analyses to validate the robustness of results.

RESULT

The study showed that the causal relationship between circulating levels of interleukin (IL)-7 and risk of TB (odds ratio [OR] = 1.001, 95% confidence intervals [CIs]: 1.000, 1.003. p = 0.047). No causal associations were observed between other influencing factors and the occurrence of TB. Furthermore, the analysis revealed that TB infection exhibited negative causal associations with macrophage inflammatory protein 1 alpha ([MIP-1α], OR = 0.007, 95% CI: 0.000, 0.192. p = 0.004), IL-2 (OR = 0.014, 95% CI: 0.010, 0.427. p = 0.014), interleukin-2 receptor alpha chain([IL-2rα], OR = 0.019, 95% CI: 0.001, 0.525. p = 0.019) and basic fibroblast growth factor ([bFGF], OR = 0.066, 95% CI: 0.006, 0.700. p = 0.024).

CONCLUSION

The study has illuminated the causal link between inflammatory cytokines and TB, thereby enhancing our comprehension of the potential mechanisms underlying TB pathogenesis. This discovery offers promising avenues for the identification of novel therapeutic targets in TB treatment. These insights may ultimately pave the way for more effective treatment approaches, thereby improving patient outcomes.

A Comparative Study on the Mechanism of Delayed-Type Hypersensitivity Mediated by the Recombinant Mycobacterium tuberculosis Fusion Protein ESAT6-CFP10 and Purified Protein Derivative

While purified protein derivative (PPD) is commonly used as skin diagnostic reagent for tuberculosis (TB) infection, it cannot distinguish effectively Bacillus Calmette-Guérin (BCG) vaccination from Mycobacterium tuberculosis (MTB) complex and nontuberculous mycobacteria infection. The new skin reagent ESAT6-CFP10 (EC) has favorable sensitivity and specificity, which can overcome limitations associated with PPD. At present, EC skin test reactions are mainly characterized by erythema, while PPD mainly causes induration. We conducted a comparative study on the potential differences between EC-induced erythema and PPD-induced induration using a guinea pig model. The size of EC-dependent erythema was similar to that of PPD-induced induration, and an inflammatory response characterized by the infiltration of monocytes, macrophages and lymphocytes, as well as tissue damage, appeared at the injection site. The lymphocytes included CD4+ T and CD8+ T cells, which released IFN-γ as the main cytokine. Both EC erythema and PPD induration could lead to increased levels of acute-phase proteins, and the differential pathways were similar, thus indicating that the main induced immune pathways were similar. The above results indicated that erythema produced by EC could generate the main delayed-type hypersensitivity (DTH) response characteristic of PPD induration, thereby suggesting that erythema might also have a certain diagnostic significance and provide a possible theoretical basis for its use as a diagnostic indicator for detecting MTB infection.

Monocyte-to-lymphocyte, neutrophil-to-lymphocyte and neutrophil-to-monocyte plus lymphocyte ratios in children with active tuberculosis: A multicentre study

AIM

Higher number of monocytes and neutrophils may correlate with active tuberculosis (TB) in children. However, the few paediatric studies available are limited by the small numbers of children with TB disease or infection included.

METHODS

We calculated the monocyte-to-lymphocyte-ratio (MLR), neutrophil-to-lymphocyte-ratio (NLR) and neutrophil-to-monocyte-plus-lymphocyte-ratio (NMLR) in children with active TB, latent TB infection (LTBI), other infectious and non-infectious conditions and healthy children evaluated in two referral centres in Rome.

RESULTS

Overall, 649 children were included (41.8% females, mean age of 5.74 years). MLR, NLR and NMLR values were always significantly higher in patients with TB compared with the other groups (p < 0.001). Considering the entire population with the outcome of TB diagnosis, NMLR, with a cut-off of 1.2, had a sensitivity of 63% and a specificity of 76% (AUC: 0.71 [0.64-0.78]); NLR, with a cut-off of 1.5, had a sensitivity of 61% and a specificity of 79% (AUC: 0.72 [0.65-0.79]); MLR, considering a cut-off of 0.2, was less sensitive (56%) but more specific (82%) with a similar AUC (0.72 [0.65-0.79]).

CONCLUSION

Our study provides further evidence that MLR, NLR and NMLR can serve as first level diagnostics to support the clinical suspicion of TB in children.

Active tuberculosis patients have high systemic IgG levels and B-cell fingerprinting, characterized by a reduced capacity to produce IFN-γ or IL-10 as a response to M.tb antigens

Introduction

Tuberculosis (TB) is a bacterial infection caused by Mycobacterium tuberculosis (M.tb). B cells are the central mediator of the humoral response; they are responsible for producing antibodies in addition to mediating other functions. The role of the cellular response during the TB spectrum by B cells is still controversial.

Methods

In this study, we evaluated the distribution of the circulating B cell subsets in patients with active and latent TB (ATB and LTB, respectively) and how they respond to stimuli of protein or lipid from M.tb.

Results

Here, we show that ATB patients show an immune fingerprinting. However, patients with drug-sensitive- (DS-TB) or drug-resistant- (DR-TB) TB have altered frequencies of circulating B cells. DS-TB and DR-TB display a unique profile characterized by high systemic levels of IFN-γ, IL-10, IgG, IgG/IgM ratio, and total B cells. Moreover, B cells from DR-TB are less efficient in producing IL-10, and both DS-TB and DR-TB produce less IFN-γ in response to M.tb antigens.

Conclusion

These results provide new insights into the population dynamics of the cellular immune response by B cells against M.tb and suggest a fingerprinting to characterize the B-cell response on DR-TB.

T-SPOT.TB Reactivity in Southern African Children With and Without in Utero Human Immunodeficiency Virus Exposure

Infants who are human immunodeficiency virus (HIV)-exposed uninfected (iHEU) experience higher risk of infectious morbidity than infants HIV-unexposed uninfected (iHUU). We compared tuberculosis (TB) infection prevalence in 418 Bacillus Calmette-Guérin vaccinated sub-Saharan African iHEU and iHUU aged 9-18 months using T-SPOT.TB. Prevalence of TB infection was low and did not differ by HIV exposure status.

Perspectives on pregnant women's educational needs to prevent TB complications during pregnancy and the neonatal period. A qualitative study

BACKGROUND

Tuberculosis (TB) during pregnancy could confer a high risk for maternal and infant morbidity. Literature indicates that the global burden of active TB disease among pregnant women is not well researched. Statistics for South Africa from WHO give an estimated incidence of 360, 000 cases of TB in 2019; 14,000 people became ill with multidrug-resistant TB in 2019, with a rate of 615 per 100,000 population, implying that the cohorts included pregnant women with and without a diagnosis of TB infection. Therefore, the study aims to increase the understanding of the educational needs required to prevent TB complications during pregnancy and the neonatal period in women diagnosed with TB infection.

METHODS

The study used cross-sectional qualitative and descriptive designs to collect data in the clinical setting of the primary health care services of Limpopo Province, South Africa. The population comprised pregnant women diagnosed with TB infection. A non-probability purposive sampling technique was used to sample 2 health centers and 5 clinics in each of the three sampled districts. The targeted sample size was 63 and it was achieved even though data saturation was observed. Individual interviews were conducted, audiotaped, and transcribed. Guided by the study questions, a thematic content analysis of the findings was used. Ethical considerations were also observed.

RESULTS

Despite that pregnant women have general knowledge about TB disease, the knowledge and awareness regarding the prevention of TB complications in pregnancy and the neonatal period, information on TB/HIV and COVID-19 co-infections, and participants' knowledge about other non-infectious diseases that may affect the mother with TB infection and foetus showed a deficit.

CONCLUSION

Pregnant women with TB disease need to be educated on the negative effects of non-adherence to TB treatment during pregnancy and the neonatal period. There is a need to educate pregnant women about the variant signs and symptoms of TB, HIV and COVID-19 infections since there is a misconception that the three diseases are similar. It is important that pregnant mothers diagnosed with TB should start treatment as soon as possible.

Mycobacterium tuberculosis infection depressed cytotoxic T cells activity owing to decreasing NKG2C and increasing NKG2A expression

Cytotoxic T lymphocytes (CTLs) play protective roles in immunity against tuberculosis (TB) infection by strongly inhibiting intracellular mycobacterial growth. In TB infection, the impairing mechanism of CTLs function remains unclear. In this study, we identified that the cytotoxic granule molecules expression levels of perforin (PRF) and granulysin (GNLY) in CD3+ and CD8+ CTL cells were significantly depressed in TB patients compared to those in healthy donors. The frequencies of T-CTLs, co-expressing granzyme B (GZMB), PRF and GNLY, were obviously decreased in TB patients. Moreover, NKG2C highly expressed in T-CTLs, was an effective activator of cytotoxic activity of CD3+ T cells. And, NKG2C+CD3+ T cells potently inhibited intracellular mycobacterial growth. The proportions of NKG2C+ cells in CD3+ and CD8+ T cells were dramatically decreased in TB patients. Contrarily, NKG2A, an inhibitor of T cells cytotoxic activities, was highly expressed in T-CTLs of CD3+ and CD8+ T cells in TB patients. Here, we successfully discovered that depressed CTLs activities in TB patients were attributed to low expression of cytotoxic granule molecules and high expression of inhibitory NKG2A receptor, suppression of agonist receptor NKG2C. Thus, NKG2 receptors were potential targets for immunotherapy of tuberculosis, especially for multidrug-resistant tuberculosis.

Latent TB Infection, Vitamin D Status and COVID-19 Severity in Mongolian Patients

We aimed to determine potential risk factors for COVID-19 severity including serum vitamin D levels and latent TB infection among Mongolian inpatients diagnosed with COVID-19, and to study the effects of disease complications and treatment outcomes. This study included patients admitted to the Mongolian National Center for Communicable Disease, a main referral center for infectious disease in Mongolia, with COVID-19 ascertained by a positive PCR test. Patients' demographic, clinical, and laboratory data were analyzed. Of the 270 patients enrolled, 125 (46%) had mild-to-moderate illness, 86 (32%) had severe illness, and 59 (22%) had critical illness. Ten (91%) of the 11 patients who had active TB were hospitalized with severe or critical COVID-19, suggesting that they had a higher risk of falling into the severe category (OR = 10.6 [1.2; 92.0] 95% CI). Severe vitamin D deficiency (25(OH)D < 10 ng/mL) was present in 32% of the patients, but was not significantly associated with the severity of illness (p = 0.65). Older age, being male, having active TB and/or COPD were associated with greater COVID-19 severity, whereas a history of COVID-19 vaccination and the presence of a BCG vaccination scar were protective in terms of disease severity.

Serum pro-inflammatory biomarkers associated with improvement in quality of life in pulmonary tuberculosis

Introduction

Pulmonary dysfunction is an underestimated complication in tuberculosis (TB) infection, affecting quality of life (QoL). Although respiratory function tests objectively reflect lung disturbances in a specific moment, predictors of illness severity at the time of diagnosis are still lacking.

Methods

We measured serum pro-inflammatory cytokines (TNF-α and IL-8), eicosanoids (PGE2, LTB4, RvD1, Mar1, and LXA4), a marker of tissue damage (cell-free nucleosomes), and indicators of redox status (malonaldehyde, 8-isoprostane, total oxidants, and antioxidants), as well as a score of radiological abnormalities (SRA) and a QoL questionnaire, in 25 patients with pulmonary TB at the time of diagnosis (t0) and two months after the initiation of treatment (t2).

Results

We found higher antioxidant levels in the patients with the worst QoL at t0, and all the indicators of the prooxidant state were significantly reduced at t2, while the total antioxidant levels increased. LTB4, a pro-inflammatory eicosanoid, was diminished at t2, while all the pro-resolutory lipids decreased substantially. Significant correlations between the SRA and the QoL scores were observed, the latter showing a substantial reduction at t2, ranking it as a reliable tool for monitoring disease evolution during TB treatment.

Discussion

These results suggest that evaluating a combination of these markers might be a valuable predictor of QoL improvement and a treatment response indicator; in particular, the oxidation metabolites and eicosanoid ratios could also be proposed as a future target for adjuvant therapies to reduce inflammation-associated lung injury in TB disease.

Incidence of switching to second-line antiretroviral therapy and its predictors among children on antiretroviral therapy at general hospitals, Northern Ethiopia: A survival analysis

BACKGROUND

With expanding access to pediatric antiretroviral therapy, several patients in the developing world were switched to the second-line regimen, and some require third-line medications. A delay in a second-line switch is associated with an increased risk of mortality and other undesired therapeutic outcomes, drives up program costs, and challenges the pediatric antiretroviral therapy service. Nevertheless, there remain limited and often conflicting estimates on second-line antiretroviral therapy use during childhood, especially in resource-limited settings like Ethiopia. Thus, this study intended to determine the incidence and predictors of switching to second-line antiretroviral therapy among children.

METHODS

A retrospective cohort study was conducted by reviewing records of 424 randomly selected children on first-line antiretroviral therapy from January 2014 to December 2018 at public hospitals in the Central and Southern Zones of Tigray, Northern Ethiopia. Data were collected using extraction tool; entered into Epi-data; cleaned, and analyzed by STATA version-14. Kaplan-Meier curve, log-rank test, and life table were used for data description and adjusted hazard ratios and p-value for analysis by Cox proportional hazard regression. Variables at a P-value of ≤0.20 in the bi-variable analysis were taken to multivariable analysis. Finally, statistical significance was declared at a P-value of ≤0.05.

RESULTS AND CONCLUSION

Analysis was conducted on 424 charts with a total person-time observation of 11686.1 child-months and an incidence switch rate of 5.6 (95%CI: 4.36-7.09) per 1000 child-month-observations. Being orphan [AHR = 2.36; 95%CI: 1.10-5.07], suboptimal adherence [AHR = 2.10; 95% CI: 1.12-3.92], drug toxicity [AHR = 7.05; 95% CI: 3.61-13.75], advanced latest clinical stage [AHR = 2.75; 95%CI: 1.05-7.15], and tuberculosis co-infection at baseline [AHR = 3.08; 95%CI: 1.26-7.51] were significantly associated with switch to second-line antiretroviral therapy regimen. Moreover, a long duration of follow-up [AHR = 0.75; 95% CI: 0.71-0.81] was associated with decreased risk of switching. Hence, it is better to prioritize strengthening the focused evaluation of tuberculosis co-infection and treatment failure with continuous adherence monitoring. Further research is also needed to evaluate the effect of drug resistance.

MicroRNA hsa-miR-320a-3p and Its Targeted mRNA FKBP5 Were Differentially Expressed in Patients with HIV/TB Co-Infection

Among the PLWH (people living with HIV) population, the risk of developing active tuberculosis (TB) is increasing. Active TB also accelerates the deterioration of PLWH's immune function and is one of the leading causes of death in the PLWH population. So far, accurate diagnosis of active TB in the PLWH population remains challenging. Through data analysis of HIV/TB co-infection in the GEO database, the differentially expressed genes as well as their related microRNA (miRNA) were acquired and were further verified through clinical blood samples. Dual-luciferase assay was used to verify the mechanism of miRNA on mRNA. The enrichment of immune cells in database patient samples was analyzed by bioinformatics and finally verified by blood routine data. Our study found that FKBP5 (FK506 binding protein 5) was highly expressed in the HIV/TB co-infection group; hsa-miR-320a-3p was highly expressed in the HIV infection group but decreased in the HIV/TB co-infection group. Dual-luciferase assay results showed that hsa-miR-320a-3p mimics significantly reduced the relative luciferase activity of the WT-FKBP5 group; however, this phenomenon was not observed in the MUT-FKBP5 group. At the same time, as a key molecule of the immune-related pathway, FKBP5 is highly correlated with the amount of neutrophils, which provides a new suggestion for the treatment of the HIV/TB co-infection population. Our study found that hsa-miR-320a-3p can decrease FKBP5 expression, suggesting a potential regulatory role for FKBP5. The involvement of FKBP5 and its related molecule hsa-miR-320a-3p in HIV/TB co-infection proposes them as potential biomarkers for the diagnosis of active TB in the PLWH population.

Phenotypic and genotypic drug susceptibility patterns of Mycobacterium tuberculosis isolates from pulmonary tuberculosis patients in Central and Southern Ethiopia

INTRODUCTION

The persistence of tuberculosis (TB) infection in some patients after treatment has highlighted the importance of drug susceptibility testing (DST). This study aimed to determine the drug susceptibility patterns of Mycobacterium tuberculosis (M. tuberculosis) isolates from pulmonary TB (PTB) patients in Central and Southern Ethiopia.

METHODS

A health institution-based cross-sectional study was conducted between July 2021 and April 2022. Sputum samples were collected from newly diagnosed smear microscopy and/or Xpert MTB/RIF-positive PTB patients. The samples were processed and cultivated in Lowenstein-Jensen (LJ) pyruvate and glycerol medium. M. tuberculosis isolates were identified using polymerase chain reaction (PCR) based region of difference 9 (RD9) deletion typing. Phenotypic DST patterns of the isolates were characterized using the BACTEC MGIT™ 960 instrument with SIRE kit. Isoniazid (INH) and Rifampicin (RIF) resistant M. tuberculosis isolates were identified using the GenoType® MTBDRplus assay.

RESULTS

Sputum samples were collected from 350 PTB patients, 315 (90%) of which were culture-positive, and phenotypic and genotypic DST were determined for 266 and 261 isolates, respectively. Due to invalid results and missing data, 6% (16/266) of the isolates were excluded, while 94% (250/266) were included in the paired analysis. According to the findings, 14.4% (36/250) of the isolates tested positive for resistance to at least one anti-TB drug. Gene mutations were observed only in the rpoB and katG gene loci, indicating RIF and high-level INH resistance. The GenoType® MTBDRplus assay has a sensitivity of 42% and a specificity of 100% in detecting INH-resistant M. tuberculosis isolates, with a kappa value of 0.56 (95%CI: 0.36-0.76) compared to the BACTEC MGIT™ DST. The overall discordance between the two methods was 5.6% (14/250) for INH alone and 0% for RIF resistance and MDR-TB (resistance to both INH and RIF) detection.

CONCLUSION

This study reveals a higher prevalence of phenotypic and genotypic discordant INH-resistant M. tuberculosis isolates in the study area. The use of whole-genome sequencing (WGS) is essential for gaining a comprehensive understanding of these discrepancies within INH-resistant M. tuberculosis strains.

Identification of Hub Genes and Typing of Tuberculosis Infections Based on Autophagy-Related Genes

Tuberculosis (TB) caused by Mycobacterium tuberculosis is one of the leading causes of morbidity and death in humans worldwide. Some autophagy genes associated with TB and some miRNAs regulating TB have been found, but the identification of autophagy-related genes in M. tuberculosis remains to be explored. Forty-seven autophagy-related genes differentially expressed in TB were identified in this study by analysis of TB-related datasets in the Gene Expression Omnibus (GEO) and autophagy-related genes in the Human Autophagy Database. The potential crucial genes affecting TB were found through the protein-protein interaction (PPI) network, and the possible pathways affected by these genes were verified. Analysis of the PPI network of miRNAs associated with M. tuberculosis infection and their target genes revealed that hsa-let-7, hsa-mir-155, hsa-mir-206, hsa-mir-26a, hsa-mir-30a, and hsa-mir-32 may regulate the expression of multiple autophagy-related genes (MAPK8, UVRAG, UKL2, and GABARAPL1) alone or in combination. Subsequently, Cytoscape was utilized to screen the differentially expressed genes related to autophagy. The hub genes (GABARAPL1 and ULK2) affecting TB were identified. Combined with Gene Set Enrichment Analysis (GSEA), the signaling pathways affected by the hub genes were verified. Finally, we divided TB patients into two subgroups based on autophagy-related genes, and the immune microenvironment of patients in different subgroups was significantly different. Our study found two autophagy-related hub genes that could affect TB and divide TB samples into two subgroups. This finding is of great significance for TB treatment and provides new ideas for exploring the pathogenesis of M. tuberculosis.

PET-CT for characterising TB infection (TBI) in immunocompetent subjects: a systematic review

Introduction. There is emerging evidence of a potential role for PET-CT scan as an imaging biomarker to characterise the spectrum of tuberculosis infection (TBI) in humans and animal models.Gap Statement. Synthesis of available evidence from current literature is needed to understand the utility of PET-CT for characterising TBI and how this may inform application of PET-CT in future TBI research.Aim. The aims of this review are to summarise the evidence of PET-CT scan use in immunocompetent hosts with TBI, and compare PET-CT features observed in humans and animal models.Methodology. MEDLINE, Embase and PubMed Central were searched to identify relevant publications. Studies were selected if they reported PET-CT features in human or animals with TBI. Studies were excluded if immune deficiency was present at the time of the initial PET-CT scan.Results. Six studies - four in humans and two in non-human primates (NHP) were included for analysis. All six studies used 2-deoxy-2-[18F]fluoro-d-glucose (2-[18F]FDG) PET-CT. Features of TBI were comparable between NHP and humans, with 2-[18F]FDG avid intrathoracic lymph nodes observed during early infection. Progressive TBI was characterised in NHP by increasing 2-[18F]FDG avidity and size of lesions. Two human studies suggested that PET-CT can discriminate between active TB and inactive TBI. However, data synthesis was generally limited by human studies including inconsistent and poorly characterised cohorts and the small number of eligible studies for review.Conclusion. Our review provides some evidence, limited primarily to non-human primate models, of PET-CT utility as a highly sensitive imaging modality to reveal and characterise meaningful metabolic and structural change in early TBI. The few human studies identified exhibit considerable heterogeneity. Larger prospective studies are needed recruiting well characterised cohorts with TBI and adopting a standardized PET-CT protocol, to better understand utility of this imaging biomarker to support future research.