The risk of tuberculosis in children after close exposure: a systematic review and individual-participant meta-analysis

Timing and predictors of disease incidence among named contacts of reported tuberculosis patients in a low incidence setting

Contact investigations are crucial for tuberculosis (TB) control, yet the temporal dynamics of disease progression among exposed contacts remain poorly understood. We conducted a retrospective cohort study of 44,106 contacts linked to 6,243 index TB cases diagnosed between 2009 and 2023. During the 15-year follow-up, 454 contacts developed TB disease, with 43.4% being incident cases. Using time-to-event analysis with left truncation to account for varying follow-up times, and mixed effect Cox models to account for index case and county-level variability, we estimated the median time to TB incidence at 11 (IQR 4-48) months after initiating contact investigation. The risk of TB disease varied markedly by age and immune status. Children aged 0-15 showed over nine times higher risk compared to adults aged 25-44 (aHR = 9.59; 95% CI: 3.17-29.02; p < 0.001). Contacts co-infected with HIV demonstrated a three-fold increased risk of TB (aHR = 2.35; 95% CI: 1.08-5.10; p = 0.031) relative to those without HIV. A history of a previous TB diagnosis conferred a protective effect on the risk of TB incident (aHR = 0.40; 95% CI: 0.20-0.80; p = 0.009). Additionally, individuals who had incomplete therapy for latent TB infection (LTBI) also experienced a protective effect (aHR = 0.32; 95% CI: 0.15-0.71; p = 0.005). These findings highlight a critical window for intervention with follow-up needed for at least 1-4 years after initial contact investigations. The results also emphasize the need for targeted, risk-stratified surveillance and LTBI treatment for children and individuals with HIV who are contacts of confirmed TB cases.

Tuberculosis disease among people with HIV: therapeutic advances

Over the past 80 years, tuberculosis treatment has evolved with the development of all-oral treatments, which are now given for 4-6 months for drug-sensitive tuberculosis and 6-9 months for drug-resistant tuberculosis. Treatment success is often reduced among people with HIV due to an interplay of factors, including immune dysregulation, lower drug concentrations, complexities of cotreatment (eg, high pill burden and overlapping toxicities), and social factors. Recent clinical trials have shown that among adults and adolescents, treatment duration can be decreased to 4 months with repurposed therapeutics for drug-sensitive tuberculosis, and a four-drug regimen of isoniazid, rifapentine, moxifloxacin, and pyrazinamide has become part of WHO recommendations. Among children with drug-sensitive, non-severe tuberculosis disease, a 4-month regimen of standard tuberculosis drugs (eg, isoniazid, rifampicin, pyrazinamide, and ethambutol) is non-inferior to a 6-month regimen. Following recent research advances for drug-resistant tuberculosis, a 6-month regimen containing a potent combination of bedaquiline, pretomanid, linezolid, and moxifloxacin is a new standard for people with and without HIV. The tuberculosis drug development pipeline contains promising new therapeutics in various stages of development. To accelerate tuberculosis elimination, future research should focus on shortened treatment duration, and safer and effective therapeutics for tuberculosis-affected populations globally, including people with HIV, children, and pregnant people, and should assess newer modalities of treatment delivery.

Tuberculosis among young contacts of patients with multidrug-resistant pulmonary tuberculosis in a reference hospital

OBJECTIVES

Young contacts of pulmonary tuberculosis (TB) patients face a higher risk of TB. Still, few studies have evaluated this risk among contacts of patients with pulmonary multidrug-resistant tuberculosis (MDR-TB). This study aimed to describe the incidence rate and the prevalence of TB infection (TBI) and TB disease (TBD) in young contacts of patients with MDR-TB.

METHODS

The authors retrospectively evaluated contacts of patients with pulmonary TB aged 0 to 19 for TBI and TBD in Rio de Janeiro between 2006 and 2016. Based on the drug susceptibility pattern and/or therapeutic regimen of the index case, contacts were classified into MDR-TB and non-MDR-TB contacts. A tuberculin skin test ≥ 5 mm was considered positive. Preventive therapy with isoniazid was offered to eligible contacts. Bivariate and multivariate logistic regressions estimated factors associated with TBI.

RESULTS

439 contacts were screened; 129 were MDR-TB and 310 were non-MDR-TB contacts. TBI prevalence was 68.2 % in MDR-TB vs. 61.9 % in non-MDR-TB contacts (p = 0.23). Tuberculin conversion was higher among MDR-TB contacts (45.5 % vs. 17.1 %; p = 0.04). TBD incidence rate was 47.7 in non-MDR-TB and 179.6 per 100,000 person-months in MDR-TB contacts (p = 0.65), for a total TBD prevalence of 2.5 %. The overall TPT completion rate was 67.2 %; 71.5 % in non-MDR-TB and 59 % in MDR-TB contacts (p = 0.04).

CONCLUSION

The authors identified a high prevalence of TBI among contacts of pulmonary MDR-TB and non-MDR-TB patients, with a higher tuberculin conversion rate in MDR-TB contacts, highlighting the urgency of effective TPT regimens for young contacts of patients with pulmonary MDR-TB.

Treatment completion and safety profile of once-weekly 3HP regimen for tuberculosis preventive treatment in children and adolescents: a systematic review

BACKGROUND

Children and adolescents are at increased risk of progressing from latent to active tuberculosis (TB). The 3-month, once-weekly isoniazid and rifapentine (3HP) regimen offers a shorter tuberculosis preventive treatment (TPT) option. However, evidence regarding its completion rates and safety in these populations remains limited.

OBJECTIVE

To evaluate treatment completion rates and adverse events associated with the 3HP regimen in children and adolescents.

METHODS

A systematic review of studies evaluated the 3HP regimen in children and adolescents with LTBI was conducted. Databases including PubMed, Embase, Cochrane Library, and CINAHL were searched to identify relevant studies. Data on treatment completion rates and adverse events were extracted and analyzed descriptively.

RESULTS

Ten studies involving children and adolescents aged 0-20 years were reviewed. Treatment completion rates were higher with 3HP regimen ranged from 70.9 to 100%, with a favorable safety profile. Mild adverse events, including nausea, vomiting, and abdominal pain, were reported, with no serious adverse events or hepatotoxicity observed.

CONCLUSIONS

The 3HP regimen demonstrates high completion rates and safety profile in children and adolescents with LTBI, highlighting its suitability for this population. Expanding its implementation in programmatic settings is crucial to advancing global TB elimination.

Tuberculosis

Tuberculosis is a leading cause of death globally. Given the airborne transmission of tuberculosis, anybody can be infected, but people in high-incidence settings are more exposed. Risk of progression to disease is higher in the first years after infection, and in people with undernourishment, immunosuppression, or who smoke, drink alcohol, or have diabetes. Although cough, fever, and weight loss are hallmark symptoms, people with tuberculosis can be asymptomatic, so a high index of suspicion is required. Prompt diagnosis can be made by sputum examination (ideally with rapid molecular tests), but chest radiography can be helpful. Most people with disease can be treated with regimens of 6 months or less; longer regimens may be necessary for those with drug resistance. Central to successful treatment is comprehensive, person-centred care including addressing key determinants, such as undernourishment, smoking, and alcohol use, and optimising management of comorbidities, such as diabetes and HIV. Care should continue after treatment ends, as long-term sequelae are common. Prevention relies mostly on treatment with rifamycin-based regimens; current vaccines have limited efficacy. Ongoing research on shorter and safer regimens for infection and disease treatment, and simpler and more accurate diagnostic methods will be key for tuberculosis elimination.

Factors driving adolescent tuberculosis incidence by age and sex in 30 high-tuberculosis burden countries: a mathematical modelling study

INTRODUCTION

During adolescence, tuberculosis incidence rises, with a greater increase in males compared with females. Tuberculosis notifications and estimates infrequently disaggregate adolescent age groups. Moreover, the factors that drive the increases in overall incidence and the male-to-female (MF) ratio remain unclear.

METHODS

We constructed a mechanistic model to estimate cumulative Mycobacterium tuberculosis infection and tuberculosis disease incidence in the WHO's 30 high-tuberculosis burden countries (HBCs), which represent 86%-90% of global tuberculosis incidence. We derived infection risk from tuberculosis prevalence and assortative social mixing based on sex and age (10-14 years vs 15-19 years old). We adjusted age subgroup-specific risks of disease progression by age- and sex-specific risks of low body mass index (BMI), pregnancy and postpartum period (PPP) and HIV coinfection. We calculated population attributable fractions (PAFs) to these factors.

RESULTS

In 2019, 91.2 million (95% uncertainty interval (UI) 83.9 to 99.3 million) adolescents in the 30 HBCs had been infected with M. tuberculosis, and an estimated 1.0 million (95% UI 0.8 to 1.2 million) developed tuberculosis disease. The median PAF of tuberculosis disease to HIV, modified by antiretroviral therapy, was 1% and highest in Southern Africa. The median PAF for PPP among older adolescents of both sexes was 2.6%. The median PAF to low BMI was 16% and highest in South Asia. The MF risk ratio of tuberculosis disease was 1.2-fold higher among older adolescents, relative to young adolescents. The widening MF risk ratio was attributable mostly to low BMI, with a smaller contribution from sex-assortative social mixing.

CONCLUSION

Globally, large numbers of adolescents have been infected by M. tuberculosis and develop tuberculosis disease. Low BMI is the most important contributor to the overall incidence of tuberculosis disease, as well as to the sex difference that widens with age.

Tuberculosis Preventive Treatment in High TB-Burden Settings: A State-of-the-Art Review

Tuberculosis (TB) is the leading cause of death from a single infectious agent. The burden is highest in some low- and middle-income countries. One-quarter of the world's population is estimated to have been infected with TB, which is the seedbed for progressing from TB infection to the deadly and contagious disease itself. Although some individuals may clear their infections through innate and acquired immunity, many do not. People living with HIV, TB-exposed household contacts, other individuals recently infected, and immunosuppressed individuals are at especially high risk of progressing to TB disease. There have been major advances in recent years to support the programmatic management of TB infection. New tests of infection, including those that predict progression to TB disease, have become available. Numerous World Health Organization-recommended TB preventive treatment (TPT) regimens are available for all ages and for both drug-susceptible and drug-resistant TB infection. All regimens are generally safe, efficacious, and cost effective and have a low risk of generating resistance. TPT is recommended for pregnant women who are at risk for developing TB, but some regimens are associated with an increased likelihood of poor obstetric and fetal outcomes, and newer regimens have not yet been tested in pregnancy. New formulations of rifapentine-based TPT have been developed, and the cost has been radically reduced. Innovative models of delivery to support the scale up of TPT have been developed. Modeling suggests that scaling up TPT, especially regimens with optimal target product profile characteristics, can contribute substantially to ending the TB epidemic. The global uptake of TPT has increased substantially, especially for people living with HIV. Implementation gaps remain, particularly for children, pregnant women, and other household contacts. Further innovation is required to support the continued scale up of TPT and to contribute to ending the TB epidemic.

Implementation of isoniazid preventive therapy among children living with diagnosed pulmonary tuberculosis patients: A mixed methods study from Mumbai, India

BACKGROUND

Tuberculosis remains a significant public health issue, particularly among children who are in close contact with tuberculosis patients. India accounts for a large proportion of global tuberculosis cases. Despite global recommendations for Isoniazid Preventive Therapy to prevent latent tuberculosis infection from progressing to active disease, the initiation and adherence to Isoniazid Preventive Therapy remain suboptimal, especially in high-burden settings. Understanding the barriers to Isoniazid Preventive Therapy implementation is crucial to improving treatment outcomes and achieving tuberculosis elimination goals.

OBJECTIVES

This study aimed to quantify the uptake of isoniazid among children under 6 years who were started on Isoniazid Preventive Therapy and to identify the challenges from the perspectives of caregivers and healthcare providers.

METHODS

The study was conducted in a slum in Mumbai, India, from June to December 2023, using a mixed-methods design. The quantitative phase involved a house-to-house survey, covering all 96 contacts started on Isoniazid Preventive Therapy in 2022, using a semi-structured questionnaire. The qualitative phase included key informant interviews with healthcare providers and in-depth interviews with caregivers. Quantitative data were analysed using Fisher's exact test and chi-square test, while qualitative data were analysed thematically.

RESULTS

Of the 96 children, 11 (11.45%) completed therapy, with an average treatment duration of 2.5 months. Quantitative findings highlighted fear of side effects and family migration as major reasons for discontinuation. Completion of chemoprophylaxis was significantly associated with factors like male gender, support from extended family, home visits by tuberculosis health staff, and shorter travel time (under 30 min) to the tuberculosis unit. Qualitative data revealed challenges across themes of supply, staff, training, services, and adherence. Key challenges included lack of awareness, unavailability of isoniazid in syrup form, inadequate training for health workers, weak program monitoring, insufficient staffing, and fears related to tuberculosis exposure during outpatient department visits.

CONCLUSION

Effective counselling, regular follow-ups, availability of medications in syrup form, increasing staffing based on case burden, timely training of staff, strengthening program monitoring, and ensuring infection control in tuberculosis outpatient departments are critical to achieving successful completion of isoniazid preventive therapy.

Effectiveness of the primary Bacillus Calmette-Guérin vaccine against the risk of Mycobacterium tuberculosis infection and tuberculosis disease: a meta-analysis of individual participant data

BACKGROUND

Tuberculosis vaccine trials using disease as the primary endpoint are large, time consuming, and expensive. An earlier immunological measure of the protection against disease would accelerate tuberculosis vaccine development. We aimed to assess whether the effectiveness of the Bacillus Calmette-Guérin (BCG) vaccine for prevention of Mycobacterium tuberculosis infection was consistent with that for prevention of tuberculosis disease.

METHODS

We conducted an individual participant data (IPD) meta-analysis on experimental and observational longitudinal studies before April 6, 2018, identified through systematic reviews, known to us through expert knowledge in the field, reporting on BCG vaccination status, M tuberculosis infection test (QuantiFERON IFN-γ release assay [IGRA] and tuberculin skin test [TST]), and tuberculosis incidence. Cohort studies were included only for countries with a mandatory neonatal BCG vaccination policy. Exclusion criteria were previous or current tuberculosis disease, HIV infection, tuberculosis preventive treatment usage, and for household contacts, a positive baseline IGRA or TST test and young children aged 0-2 years; for randomised controlled trials, TST results within 2 years after random assignation were excluded. We contacted the investigators of the identified studies to provide IPD. We compared the protective efficacy of the BCG vaccine against M tuberculosis infection with that against tuberculosis disease using mixed-effects, multivariable proportional hazards modelling, by study type, M tuberculosis infection test (IGRA and TST), cutoff for defining test positivity, age, sex, and latitude.

FINDINGS

We identified 79 studies eligible for full screening and of these, IPD datasets from 14 studies were included in our analysis: 11 household contact studies (29 147 participants), two adolescent cohort studies (11 368 participants), and one randomised controlled trial (2963 participants). Among 28 188 participants we found no protection by the BCG vaccine against TST conversion regardless of cutoff in any type of study. Among 1491 household contacts, but not among 5644 adolescents, the BCG vaccine protected against QuantiFERON conversion at the primary cutoff of 0·7 IU/mL or more with the adjusted hazard ratio (0·65, 95% CI 0·51-0·82) being consistent with that for protection against disease (0·68, 0·18-2·59). Protection against QuantiFERON conversion at cutoff of 0·35 IU/mL or more (0·64, 0·51-0·81) was similar.

INTERPRETATION

Protection from the BCG vaccination against M tuberculosis infection, measured as QuantiFERON conversion, is inconsistent across different groups. Among groups with recent household exposure, QuantiFERON conversion is consistent with protection against disease and could be evaluated as a proxy for disease in tuberculosis vaccine trials. We found that TST lacks value for prevention in phase 2b proof-of-concept trials.

FUNDING

Bill & Melinda Gates Foundation.

Interferon (IFN)-gamma (γ) inducible protein 10 (IP-10) in the diagnosis of latent and active tuberculosis in Bacille Calmette Guerin (BCG)-vaccinated pediatric population

BACKGROUND

Accurate diagnosis of tuberculosis (TB) in children continues to be challenging, primarily due to the low bacterial load characteristic of the disease and the obstacles in collecting sputum samples. Furthermore, detecting cases of latent Mycobacterium tuberculosis (M.tb) infection (LTBI) that have a high risk of progressing to active TB disease remains a significant diagnostic hurdle.

OBJECTIVE

The study explored the utility of interferon-gamma (IFN-γ) inducible protein 10 (IP-10) for diagnosing latent and active M.tb infections among children vaccinated with the Bacille Calmette-Guerin (BCG) vaccine. The research specifically assessed IP-10 levels in serum, urine, and QuantiFERON-TB Gold Plus (QFT) cultures stimulated with M.tb antigens to determine if IP-10 could be a useful diagnostic marker for pediatric tuberculosis, either alongside or as an alternative to IFN-γ.

RESULTS

Both urine and QFT cultures stimulated with M.tb antigens showed significantly higher IP-10 levels in individuals with active TB or latent TB infection (LTBI) when compared to those uninfected by M.tb but with nonmycobacterial pneumonia (NMP) and healthy controls (HC). Similarly, IFN-γ levels in M.tb-stimulated QFT cultures were significantly higher in the TB and LTBI groups compared to the NMP and HC groups. Notably, the study found a significant difference in IFN-γ levels between the TB and LTBI groups in the QFT cultures, a distinction not observed for IP-10 concentrations. Serum levels of IP-10 and IFN-γ did not significantly vary across the study cohorts.

CONCLUSIONS

IP-10 might be a viable alternative biomarker to IFN-γ for identifying M.tb infection in BCG-vaccinated children, although it cannot distinguish between latent and active TB cases. This highlights the potential of IP-10 in improving TB diagnosis among children, addressing the challenges posed by the paucibacillary nature of pediatric TB, but also underscores the need for further research to refine diagnostic approaches for distinguishing between latent and active TB infections.

Immune-sensitization to Mycobacterium tuberculosis Among Young Children With and Without Tuberculosis

Background

Identification of young children with Mycobacterium tuberculosis ( Mtb )-infection is critical to curb Tuberculosis (TB)-related pediatric morbidity and mortality. The optimal test to identify young children with evidence of Mtb -infection remains controversial.

Methods

Using a TB household contact (HHC) study design among 130 Ugandan children less than 5 years with established Mtb -exposure, we compared the usefulness of the tuberculin skin test (TST) and QuantiFERON Gold Plus (QFT-Plus) to identify children with evidence for Mtb -sensitization. We conducted univariate analysis to compare findings between children with and without TB disease, and performed a logistic regression model to estimate the odds of TB. We performed a sensitivity analysis by stratifying results by age (< 2 years vs. 2-5 years). Finally, we compared results of the QFT-Plus TB tube 1 and TB tube 2 to establish concordance.

Results

A 5 mm TST threshold identified the most children with evidence of Mtb -sensitization; this result was most pronounced in children with TB. Moreover, the odds of TB were 2 times higher [aOR: 2.09 (CI: 1.02 - 4.37)] among children with a positive TST. The QFT-Plus' TB tube 1 and TB tube 2 results were highly correlated.

Conclusions

TST identified more TB-exposed young children with evidence of Mtb- immune-sensitization, when compared to QFT-Plus. These findings are highly relevant for children who are TB HHCs in endemic settings, and most at risk for TB following an exposure. We recommend that TST testing continue to be performed to assess for Mtb -sensitization in young children.

Tuberculosis preventive treatment in newborns

OBJECTIVE

To describe the reported cases of newborns subjected to tuberculosis preventive treatment (TPT) in the state of Paraná, Brazil, and to evaluate the safety and effectiveness in preventing the progression of TB disease in this population.

METHOD

Observational, descriptive case series, with secondary data. The characteristics of the participants were analyzed from the information systems of preventive treatment of TB (of Paraná), between 2009 and 2016. To evaluate which children had developed tuberculosis later or died, we used the data from the information systems of TB (in Brazil), and mortality (in Paraná), covering the years 2009 to 2018.

RESULTS

A total of 24 children underwent TPT with the age at treatment onset ranging from 0 to 87 days (median: 23 days). In 95.8 %, the exposure occurred at home, and in 33.3 % of cases, the mother was the source of the infection. A total of 20.8 % of the children tested positive for tuberculosis test at 3 months of age, 83.3 % completed treatment, and 2 experienced adverse events (gastrointestinal issues). No children developed TB or died during the minimum of a 2-year evaluation period through the official databases.

CONCLUSIONS

In this case series, the adherence to the plan was high, with few adverse events and 100 % protection against infection.

Children and providers' perspectives on once-weekly rifapentine and isoniazid TB preventive therapy

BACKGROUND

TB preventive treatment (TPT) prevents the development of TB disease in individuals at risk of progression from infection to disease. However, implementation of TPT for children is poor in most high-burden settings. The long duration and pill burden of the 6-month once-daily isoniazid regimen (6H) pose significant barriers to completion. We aimed to understand children's, caregivers', and healthcare providers' experiences of the 12-week once-weekly rifapentine and isoniazid (3HP) regimen using a dispersible tablet formulation in South Africa.

METHODS

Serial, in-depth qualitative interviews with 20 child-caregiver dyads, including 5 children living with HIV (CLWH) and 9 healthcare providers across two study sites implementing a pharmacokinetic and safety trial of 3HP, were analysed deductively.

RESULTS

Of those with experience using both 3HP and 6H, caregivers and healthcare providers preferred 3HP, and study participants reported that the 3HP formulation was more palatable and easier to prepare and administer. Caregivers and healthcare providers were concerned about optimally integrating 3HP into routine care, primarily due to its once-weekly administration. Children with HIV preferred the once-daily 6H regimen for its ease of use with their daily antiretroviral therapy.

CONCLUSIONS

3HP reduced the administration burden for children and their caregivers. Once weekly, 3HP dosing will require education and adherence support to ensure completion.

Global burden of tuberculous meningitis in children aged 0-14 years in 2019: a mathematical modelling study

BACKGROUND

Tuberculous meningitis is fatal if untreated and can lead to lifelong neurological sequelae. However, to our knowledge, there are no data on the number of children affected by this disease. We aimed to estimate the global disease burden and attributable mortality of childhood tuberculous meningitis by WHO regions, age groups, treatment status, and HIV status in 2019.

METHODS

We developed a Bayesian mathematical model to estimate the number of children aged 0-14 years who developed tuberculous meningitis, died from tuberculous meningitis, and did not die from tuberculous meningitis but had neurological sequelae in 2019. We reviewed the literature and used meta-analyses to quantify key parameters used as model inputs: risk of tuberculous meningitis after Mycobacterium tuberculosis infection, tuberculous meningitis as a proportion of tuberculosis notification data (ie, routine surveillance data that countries report to WHO), and risk ratios for tuberculous-meningitis mortality by age group. We identified routine tuberculosis surveillance data from countries and literature that reported the proportion of notified childhood tuberculosis that was due to tuberculous meningitis. Country-level data were from Brazil; the USA; Ukraine; South Africa; and the European Centre for Disease Prevention and Control, which included 29 countries but was aggregated and considered as one site. We assumed tuberculosis notification was synonymous with detection and treatment, combined age-disaggregated risk ratios and published meta-analytic estimates of the case-fatality rate in children who received treatment to produce estimates of tuberculous-meningitis mortality by age group and HIV status, and assumed that untreated tuberculous meningitis was always fatal. We assumed similar age-disaggregated risk ratios for neurological sequelae among children who had treatment for tuberculous meningitis and lived as for children who died.

FINDINGS

An estimated 24 000 (95% credible interval 22 300-25 700) children younger than 15 years developed tuberculous meningitis in 2019. Of these children, 13 000 (12 100-13 900) were estimated to have been diagnosed and treated for tuberculous meningitis. Most untreated children were younger than 5 years. Among the 24 000 children with tuberculous meningitis, 16 100 (14 900-17 300) were estimated to have died in 2019, of whom 1101 (6·8%) had HIV. 13 380 (83·1%) of 16 100 deaths were estimated to be in children younger than 5 years and 11 000 (68·3%) were estimated to be in children who did not receive tuberculous-meningitis treatment. Of the 7900 (5800-10 000) children who did not die, 5550 (5110-5980) were estimated to have neurological sequelae.

INTERPRETATION

Our estimates of tuberculous meningitis in children younger than 15 years showed substantial mortality and morbidity. Improved diagnostics and strong health-care systems to facilitate early diagnosis are crucial to improve outcomes, and tuberculosis prevention should be a public health priority.

FUNDING

Fogarty International Center of the US National Institutes of Health.

6-month regimen of isoniazid prevention therapy for tuberculosis among people living with human immunodeficiency virus in minority areas of China: a 3-year prospective cohort study

INTRODUCTION

As China is scaling up tuberculosis preventive therapy (TPT) for people living with HIV (PLHIV) in its national programmes, the objective of this study was to evaluate the feasibility and performance of 6-month regimen of isoniazid monotherapy (6H) in terms of preventive therapy acceptance, adherence, effectiveness and outcomes in minority areas with a high burden of tuberculosis (TB) and HIV/AIDS.

METHOD

A prospective observational cohort study was initiated among 461 PLHIV in Butuo County after ruling out active TB (ATB) and followed up for up to 3 years to collect incidence events in real-world settings. TB incidence and protective rates were calculated. The risk factors related to acceptance and adherence were identified using a logistic regression model.

RESULTS

Of the 688 PLHIV screened for TB, 115 (16.72 %) had ATB. Among the 461 participants eligible for 6H, 392 (85.03%) initiated 6H, and 277 (70.67%) completed the therapy. In total, 15 were identified as having ATB during follow-up. The incidence of ATB in the complete group was 0.62/100 person years (95% CI 0.20 to 1.45) as compared with the incomplete group 2.96/100 person years (95% CI 1.36 to 5.63) (p=0.005), and the protective rate of 6H was 79.05%. The protection rate between the complete and incomplete and refusal groups was 69.31%. In total, 142 (36.22%) patients experienced adverse drug reactions during isoniazid preventive therapy. The logistic regression model revealed several factors associated with 6H acceptance: first CD4+ T lymphocyte count was between 200 and 350 cells/mm3 (adjusted OR (aOR)=0.30, 95% CI 0.10 to 0.92) or>500 cells/mm3 (aOR=0.25, 95% CI 0.08 to 0.77). Factors associated with 6H adherence: 36-45 years old (aOR=2.76, 95% CI 1.49 to 5.10), middle school education (aOR=0.26, 95% CI 0.08 to 0.79) and history of prior TB (aOR=0.09, 95% CI 0.05 to 0.20).

CONCLUSION

6H can reduce the incidence of ATB in minority areas with high burdens of TB and HIV/AIDS. Periodic counselling of patients on adherence and retraining of the TPT staff are essential. Health monitoring and education for specific populations improve TPT acceptance and adherence.

Levofloxacin Preventive Treatment in Children Exposed to MDR Tuberculosis

BACKGROUND

Worldwide, approximately 2 million children younger than 15 years of age are infected with multidrug-resistant (MDR) Mycobacterium tuberculosis, with MDR tuberculosis developing in approximately 30,000 annually. Evidence from randomized, controlled trials on tuberculosis preventive treatment in persons exposed to MDR tuberculosis is lacking.

METHODS

In this community-based, multisite, double-blind, cluster-randomized, placebo-controlled trial in South Africa, we assessed the efficacy and safety of levofloxacin as preventive treatment in children with household exposure to an adult with bacteriologically confirmed MDR pulmonary tuberculosis. Children younger than 5 years of age were eligible for inclusion regardless of interferon-γ release assay result or human immunodeficiency virus (HIV) status, and children 5 to 17 years of age were eligible if they had a positive interferon-γ release assay or HIV infection. Households were randomly assigned to a trial regimen, and children in the household received levofloxacin or placebo once daily for 24 weeks. The primary efficacy end point was incident tuberculosis, which included death from tuberculosis, by week 48 after randomization. The primary safety end point was any adverse event of grade 3 or higher during the treatment period that was at least possibly related to the trial regimen.

RESULTS

Of 922 participants from 497 households, 453 were assigned to receive levofloxacin and 469 to placebo; 91.0% of the participants were younger than 5 years of age. At least 80% of the assigned doses of levofloxacin or placebo were received by 86% of the participants in each trial group. By week 48, tuberculosis had developed in 5 participants (1.1%) in the levofloxacin group and in 12 participants (2.6%) in the placebo group (hazard ratio, 0.44; 95% confidence interval [CI], 0.15 to 1.25). The results of sensitivity analyses were consistent with those of the primary analysis. Grade 3 or higher adverse events during the treatment period that were considered to be at least possibly related to the trial regimen occurred in 4 participants in the levofloxacin group and in 8 participants in the placebo group (hazard ratio, 0.52; 95% CI, 0.16 to 1.71). Grade 2 tendonitis occurred in 1 child in the levofloxacin group.

CONCLUSIONS

Although preventive treatment with levofloxacin led to a lower incidence of tuberculosis than placebo among children with household exposure to MDR tuberculosis, the difference was not significant. (Supported by Unitaid and others; TB-CHAMP ISRCTN Registry number, ISRCTN92634082.).

Prevalence and Associated Factors of Children Tuberculosis in Southeast Asia Countries: A Systematic Review

Southeast Asia (SEA) countries are characterised by a high burden of tuberculosis (TB). This research seeks to compile evidence of the prevalence and risk factors associated with TB among children in SEA countries. The searching of articles was conducted for four databases (PubMed, Scopus, Embase, and the Web of Science) published between 2013 and 2023 in the English language. The quality of articles was evaluated using the Joanna Briggs Institute (JBI) Critical Appraisal Tool for Assessment of Risk Bias for Cross-Sectional studies. This research was reported using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guideline. Eight studies were included in the systematic review. The prevalence of paediatric TB in SEA countries varies between 1.50% and 38.10%. Risk factors associated with the occurrence of TB in children include the nutritional status, the Bacillus Calmette-Guérin (BCG) vaccine status, close contact with TB patients, parental smoking behaviour, unhealthy living conditions, and socioeconomic determinants. The continued high prevalence of TB in several SEA countries, particularly among children, remains a significant public health concern. The various risk factors summarised can serve as a basis for implementing interventions aimed at reducing cases and preventing the transmission of TB among children.

Mycobacterium tuberculosis infection and tuberculosis disease in the first decade of life: a South African birth cohort study

BACKGROUND

Paediatric tuberculosis leads to more than 200 000 deaths annually. We aimed to investigate the incidence of Mycobacterium tuberculosis infection and tuberculosis disease in the first decade of life in the Drakenstein Child Health Study (DCHS), a South African cohort in a community with high tuberculosis and HIV incidence.

METHODS

In this prospective birth cohort study, we enrolled pregnant women aged 18 years or older who were between 20 and 28 weeks' of gestation in a peri-urban setting outside of Cape Town, South Africa. We followed up their children for tuberculosis until age 10 years. To measure M tuberculosis infection tuberculin skin tests were administered to children at age 6 months, 12 months, and then annually in children with a negative test, and at the time of a lower respiratory tract infection. Tuberculin skin test conversion was defined by an induration reaction of 10 mm or more. To measure tuberculosis disease, active surveillance was done throughout follow-up. Each episode of presumed tuberculosis disease was investigated using sputum induction, tested with Xpert MTB/RIF and liquid culture for M tuberculosis. Survival analyses were performed and multivariable Cox regression was used to measure factors associated with M tuberculosis infection or disease.

FINDINGS

Between March 5, 2012, and March 31, 2015, 1137 women and their 1143 children (248 [21·7%] of 1143 children were HIV-exposed, two [0·2%] children with HIV) were included in the analysis. Children were followed up for 8870 person-years (median follow-up 9·1 years [IQR 8·2-10·2]). The annual risk of tuberculin conversion during follow-up was 6·6 infections per 100 person-years (95% CI 5·8-7·3) but ranged from 4-9 infections per 100 person-years over the follow-up period. 98 children developed tuberculosis (1105 cases per 100 000 person-years; 95% CI 906-1347). The cumulative hazard of tuberculin conversion was 36% (95% CI 32-41) at age 8 years and the cumulative hazard of tuberculosis disease was 10% (8-12) at age 10 years. Preventive treatment was associated with a reduction in tuberculosis disease among children who had tuberculin conversion (adjusted hazard ratio 0·23 [95% CI 0·12-0·47]). Most cases of tuberculosis disease (78 [79%; 95% CI 69-86] of 98 children) occurred among children who had tuberculin skin test conversion but were not administered preventive treatment.

INTERPRETATION

In this prospective South African birth cohort, M tuberculosis transmission was consistently high throughout the first decade of life leading to approximately 10% of children developing tuberculosis disease. A multipronged approach to decrease paediatric tuberculosis is needed that combines preventive treatment for children at risk, reducing community M tuberculosis transmission, and active case finding.

FUNDING

Bill & Melinda Gates Foundation, Medical Research Council South Africa, and National Research Foundation South Africa.

Added Value of Medical Subject Headings Terms in Search Strategies of Systematic Reviews: Comparative Study

BACKGROUND

The massive increase in the number of published scientific articles enhances knowledge but makes it more complicated to summarize results. The Medical Subject Headings (MeSH) thesaurus was created in the mid-20th century with the aim of systematizing article indexing and facilitating their retrieval. Despite the advent of search engines, few studies have questioned the relevance of the MeSH thesaurus, and none have done so systematically.

OBJECTIVE

The objective of this study was to estimate the added value of using MeSH terms in PubMed queries for systematic reviews (SRs).

METHODS

SRs published in 4 high-impact medical journals in general medicine over the past 10 years were selected. Only SRs for which a PubMed query was provided were included. Each query was transformed to obtain 3 versions: the original query (V1), the query with free-text terms only (V2), and the query with MeSH terms only (V3). These 3 queries were compared with each other based on their sensitivity and positive predictive values.

RESULTS

In total, 59 SRs were included. The suppression of MeSH terms had an impact on the number of relevant articles retrieved for 24 (41%) out of 59 SRs. The median (IQR) sensitivities of queries V1 and V2 were 77.8% (62.1%-95.2%) and 71.4% (42.6%-90%), respectively. V1 queries provided an average of 2.62 additional relevant papers per SR compared with V2 queries. However, an additional 820.29 papers had to be screened. The cost of screening an additional collected paper was therefore 313.09, which was slightly more than triple the mean reading cost associated with V2 queries (88.67).

CONCLUSIONS

Our results revealed that removing MeSH terms from a query decreases sensitivity while slightly increasing the positive predictive value. Queries containing both MeSH and free-text terms yielded more relevant articles but required screening many additional papers. Despite this additional workload, MeSH terms remain indispensable for SRs.

Tuberculosis Preventive Treatment for Pregnant People With Human Immunodeficiency Virus in South Africa: A Modeling Analysis of Clinical Benefits and Risks

BACKGROUND

Although prior studies of tuberculosis-preventive treatment (TPT) for pregnant people with human immunodeficiency virus (PPWH) report conflicting adverse pregnancy outcome (APO) risks, international guidelines recommend TPT for PPWH.

METHODS

We used a microsimulation model to evaluate 5 TPT strategies among PPWH receiving antiretroviral therapy in South Africa: No TPT; 6 months of isoniazid (6H) or 3 months of isoniazid-rifapentine (3HP) during pregnancy (Immediate 6H or Immediate 3HP) or post partum (Deferred 6H or Deferred 3HP). The primary outcomes were maternal, fetal/infant, and combined deaths from causes potentially influenced by TPT (maternal tuberculosis, maternal hepatotoxicity, stillbirth, low birth weight [LBW], and infant tuberculosis). Tuberculosis during pregnancy confers 250% and 81% higher modeled risks of stillbirth and LBW, respectively. In lower-risk or higher-risk scenarios, immediate TPT confers 38% lower or 92% higher risks of stillbirth and 16% lower or 35% higher risks of LBW.

RESULTS

Immediate TPT would minimize deaths among PPWH. When TPT confers higher stillbirth and LBW risks, immediate TPT would produce the most combined maternal and fetal/infant deaths, even with low maternal CD4 cell count and high tuberculosis incidence. If immediate TPT yields a <4% or <20% increase in stillbirth or LBW, immediate TPT would produce fewer combined deaths than deferred TPT (sensitivity analysis range, <2%-22% and <11%-120%, respectively).

CONCLUSIONS

If APO risks are below identifiable thresholds, TPT during pregnancy could decrease combined maternal and fetal/infant deaths. Given uncertainty around isoniazid's risks, and the low threshold at which APO risks could outweigh benefits from tuberculosis deaths averted, studies of newer TPT regimens among PPWH are warranted to inform guidelines.

Effect of CD4 count on Mycobacterium tuberculosis infection rates in people living with HIV: a comparative study in prison and community

To evaluate the impact of the CD4 count on ESAT6-CFP10 (EC) skin test, QuantiFERON-TB Gold In-tube test (QFT) and tuberculin skin test (TST) in a large prison and communities in Jiangsu Province among people living with HIV (PLHIV). Participants in communities were tested with the QFT and EC skin test and in prison were tested with the QFT, TST and EC skin test. A 4-knotted restricted cubic spline fitted for Logistic models was used to explore the cutoff point of CD4 count and the associations between changes in CD4 count and Mycobacterium tuberculosis (M.tb) infection. Among 1,815 PLHIV included, 19.3% (350) were from prisons and 80.7% (1465) were identified through community screenings. M.tb infection rates were 12.2% and 8.3% through QFT and EC tests, respectively. Odd Ratios (ORs) for infection increased with CD4 counts, peaking at 618 cells/mm3 for EC, 392 cells/mm3 for QFT, then plateaued. However, the pattern differed for EC between prison and screening scenarios. In prison settings, M.tb infection increased with CD4 count from 0 to 350 cells/mm3, plateaued until 500 cells/mm3, and then persistently increased. Conversely, for community, ORs decreased until 300 cells/mm3, followed by an increase between 300 and 729 cells/mm3, after which they continued to rise persistently. Our cross-sectional study among PLHIV revealed a higher rate of M.tb infection in prison compared to the community. The relationship between CD4 count and infection became negative after a certain threshold. This pivotal point differed with detection methods, with QFT showing lower CD4 thresholds than EC.

Factors Affecting the Integration of Pediatric TB Screening in Kabale District of Uganda: A Cross Sectional Study

Background

Globally, >1.1 million children had tuberculosis (TB) and >214,000 died in 2022. The integration of pediatric TB screening should help in the identification and management of cases among children attending clinics at entry points. This study aimed to establish the extent of integrating pediatric TB screening into mainstream childcare activities and the factors affecting integration of TB screening among children.

Methods

A cross-sectional design using both quantitative and qualitative methods. Simple random sampling was used to select and observe 40 participants for integration of TB screening in the routine assessment of children. Twenty key informants were interviewed and two focus group discussions conducted on the integration of pediatric TB screening.

Results

Of the 302 children assessed, only 41.1% underwent pediatric TB screening integrated in their assessment. A binary logistic regression model using Wald chi-square showed that a cadre having worked at outpatient department (OPD) and young child clinic (YCC) significantly affected integration, with a p-value of 0.002 and 95% CI (1.040-1.152) and a p-value of 0.002 and 95% CI (1.000-1.519). Participants who had 3 to 5 years in service were 7.05 times more likely to integrate pediatric TB screening at the OPD and Cadres who had over 6 years in service were 6.32 times more likely at the YCC. Being a nurse or a midwife was associated with an increased likelihood of integrating pediatric tuberculosis screening. Knowledge, skills, and confidence gaps in screening and assessing for tuberculosis in children among staff and lack of necessary logistics were identified barriers.

Conclusion

The integration of pediatric TB screening in routine assessments at the OPD/YCC was low. Focus more on HC IIIs to improve health workers' involvement and capacity to integrate TB screening at entry points in health facilities and provide logistics.

Treatment of Tuberculous Pleurisy With Contezolid in a Child With Glucose-6-Phosphate Dehydrogenase Deficiency: The First Case Report

This is the first reported case of a pediatric patient with tuberculous pleurisy and glucose-6-phosphate dehydrogenase deficiency treated with contezolid concomitantly with other antituberculous drugs. The patient responded well to treatment, and no adverse events were observed. These findings suggest that contezolid may be a potential therapeutic option for tuberculous pleurisy in children and adolescents with glucose-6-phosphate dehydrogenase deficiency.

3HP preventive treatment among children and adolescents with HIV and child household contacts of TB patients

INTRODUCTION

India's National TB Elimination Programme plans to roll out short-course TB preventive therapy (TPT) using 3 months of rifapentine and isoniazid (3HP). Understanding the feasibility and safety of children in programmatic settings is critical for widespread implementation. We present the findings of a targeted scale-up of 3HP among children and adolescents living with HIV (CALHIV) and child household contacts (>2 to <6 years) of pulmonary TB patients (CHHC).

METHODS

Between December 2021 and July 2023, eligible CALHIV and CHHC participants were given weekly dosages of 3HP for 3 months at antiretroviral therapy (ART) and TB clinics, respectively, of a public hospital in Pune, India.

RESULTS

Of 97 children screened, 91 initiated 3HP (32 CALHIV and 59 CHHC). The median age of CALHIV was 14 years; 66% were male and on dolutegravir-based ART. The median age of CHHC was 4 years; 47% were males. Thirty-one (97%) CALHIV and 56 (95%) CHHC completed 3HP without dolutegravir dose adjustment. None of the child participants discontinued 3HP due to adverse events. No child participant developed TB during 1 year of follow-up post-3HP.

CONCLUSION

Our study provides evidence of the uptake and feasibility of the planned nationwide rollout of 3HP.

Isoniazid preventive therapy during infancy does not adversely affect growth among HIV-exposed uninfected children: Secondary analysis of data from a randomized controlled trial

BACKGROUND

Isoniazid preventive therapy (IPT) decreases risk of tuberculosis (TB) disease; impact on long-term infant growth is unknown. In a recent randomized trial (RCT), we assessed IPT effects on infant growth without known TB exposure.

METHODS

The infant TB Infection Prevention Study (iTIPS) trial was a non-blinded RCT among HIV-exposed uninfected (HEU) infants in Kenya. Inclusion criteria included age 6-10 weeks, birthweight ≥2.5 kg, and gestation ≥37 weeks. Infants in the IPT arm received 10 mg/kg isoniazid daily for 12 months, while the control trial received no intervention; post-trial observational follow-up continued through 24 months of age. We used intent-to-treat linear mixed-effects models to compare growth rates (weight-for-age z-score [WAZ] and height-for-age z-score [HAZ]) between trial arms.

RESULTS

Among 298 infants, 150 were randomized to IPT, 47.6% were females, median birthweight was 3.4 kg (interquartile range [IQR] 3.0-3.7), and 98.3% were breastfed. During the 12-month intervention period and 12-month post-RCT follow-up, WAZ and HAZ declined significantly in all children, with more HAZ decline in male infants. There were no growth differences between trial arms, including in sex-stratified analyses. In longitudinal linear analysis, mean WAZ (β = 0.04 [95% CI:-0.14, 0.22]), HAZ (β = 0.14 [95% CI:-0.06, 0.34]), and WHZ [β = -0.07 [95% CI:-0.26, 0.11]) z-scores were similar between arms as were WAZ and HAZ growth trajectories. Infants randomized to IPT had higher monthly WHZ increase (β to 24 months 0.02 [95% CI:0.01, 0.04]) than the no-IPT arm.

CONCLUSION

IPT administered to HEU infants did not significantly impact growth outcomes in the first two years of life.

Tuberculosis treatment loss to follow-up in children exposed at home: A prospective cohort study

Background

Loss to follow-up (LTFU) from tuberculosis (TB) treatment and care is a significant public health problem. It is important to understand what drives LTFU in children - a population whose treatment and management depend on an adult caregiver - to better provide support services to families affected by TB.

Methods

We conducted a prospective cohort study of household contacts in Lima, Peru (2009-12). Using multilevel logistic regression analysis, we explored individual-level characteristics of children and their adult household members with TB disease to identify risk factors for LTFU among children initiated on treatment for TB.

Results

A total of 154 child (0-14 years) household contacts were diagnosed with TB and initiated on treatment. While most (n = 133, 86.4%) had a successful outcome, 20 (13.0%) children were LTFU. Six (30.0%) children were LTFU within three months, nine (45.0%) between five to seven months, and three (15.0%) after seven months of treatment being initiated. In univariable analysis, children with index patients above 25 years of age had decreased odds of being LTFU (odds ratio = 0.26; 95% confidence interval = 0.08-0.84) compared to children with index patients 25 years or younger.

Conclusions

In this cohort, more than 10% of children sick with TB who were exposed to the disease at home were LTFU. An integrated, family-centred TB prevention and management approach may reduce barriers to a child completing their course of TB treatment.

Effectiveness of preventive treatment among different age groups and Mycobacterium tuberculosis infection status: a systematic review and individual-participant data meta-analysis of contact tracing studies

BACKGROUND

Tuberculosis is a preventable disease. However, there is debate regarding which individuals would benefit most from tuberculosis preventive treatment and whether these benefits vary in settings with a high burden and low burden of tuberculosis. We aimed to compare the effectiveness of tuberculosis preventive treatment in exposed individuals of differing ages and Mycobacterium tuberculosis infection status while considering tuberculosis burden of the settings.

METHODS

In this systematic review and individual-participant meta-analysis, we investigated the development of incident tuberculosis in people closely exposed to individuals with tuberculosis. We searched for studies published between Jan 1, 1998, and April 6, 2018, in MEDLINE, Web of Science, BIOSIS, and Embase. We restricted our search to cohort studies; case-control studies and outbreak reports were excluded. Two reviewers evaluated titles, abstracts, and full text articles for eligibility. At each stage, two reviewers discussed discrepancies and re-evaluated articles until a consensus was reached. Individual-participant data and a pre-specified list of variables, including characteristics of the exposed contact, the index patient, and environmental characteristics, were requested from authors of all eligible studies; contacts exposed to a drug-resistant tuberculosis index patient were excluded. The primary study outcome was incident tuberculosis. We estimated adjusted hazard ratios (aHRs) for incident tuberculosis with mixed-effects Cox regression models with a study-level random effect. We estimated the number-needed-to-treat (NNT) to prevent one person developing tuberculosis. Propensity score matching procedures were used in all analyses. This study is registered with PROSPERO (CRD42018087022).

FINDINGS

After screening 25 358 records for eligibility, 439 644 participants from 32 cohort studies were included in the individual-participant data meta-analysis. Participants were followed for 1 396 413 person-years (median of 2·7 years [IQR 1·3-4.4]), during which 2496 people were diagnosed with incident tuberculosis. Overall, effectiveness of preventive treatment was 49% (aHR 0·51 [95% CI 0·44-0·60]). Participants with a positive tuberculin-skin-test (TST) or IFNγ release assay (IGRA) result at baseline benefitted from greater protection, regardless of age (0·09 [0·05-0·17] in children younger than 5 years, 0·20 [0·15-0·28] in individuals aged 5-17 years, and 0·17 [0·13-0·22] in adults aged 18 years and older). The effectiveness of preventive treatment was greater in high-burden (0·31 [0·23-0·40]) versus low-burden (0·58 [0·47-0·72]) settings. The NNT ranged from 9 to 34 depending on age among participants with a positive TST or IGRA in both high-burden and low-burden settings; among all contacts (regardless of TST or IGRA test result), the NNT ranged from 29 to 43 in high-burden settings and 213 to 455 in low-burden settings.

INTERPRETATION

Our findings suggest that a risk-targeted strategy prioritising contacts with evidence of M tuberculosis infection might be indicated in low-burden settings, and a broad approach including all contacts should be considered in high-burden settings. Preventive treatment was similarly effective among contacts of all ages.

FUNDING

None.

Incidence and predictors of tuberculosis among HIV-infected children after initiation of antiretroviral therapy in Ethiopia: A systematic review and meta-analysis

BACKGROUND

Globally, Tuberculosis (TB) is the main cause of morbidity and mortality among infectious disease. TB and Human Immune Virus (HIV) are the two deadly pandemics which interconnected each other tragically, and jeopardize the lives of children; particularly in Sub-Saharan Africa. Therefore, this review was aimed to determine the aggregated national pooled incidence of tuberculosis among HIV- infected children and its predictors in Ethiopia.

METHODS

An electronic search engine (HINARI, PubMed, Scopus, web of science), Google scholar and free Google databases were searched to find eligible studies. Quality of the studies was checked using the Joanna Briggs Institute (JBI) quality assessment checklists for cohort studies. Heterogeneity between studies was evaluated using Cochrane Q-test and the I2 statistics.

RESULT

This review revealed that the pooled national incidence of tuberculosis among children with HIV after initiation of ART was 3.63% (95% CI: 2.726-4.532) per 100-person-years observations. Being Anemic, poor and fair ART adherence, advanced WHO clinical staging, missing of cotrimoxazole and isoniazid preventing therapy, low CD4 cell count, and undernutrition were significant predictors of tuberculosis incidence.

CONCLUSION

The study result indicated that the incidence of TB among HIV- infected children is still high. Therefore, parents/guardians should strictly follow and adjust nutritional status of their children to boost immunity, prevent undernutrition and opportunistic infections. Cotrimoxazole and isoniazid preventive therapy need to continually provide for HIV- infected children for the sake of enhancing CD4/immune cells, reduce viral load, and prevent from advanced disease stages. Furthermore, clinicians and parents strictly follow ART adherence.

Optimizing the cascade of prevention to protect people from tuberculosis: A potential game changer for reducing global tuberculosis incidence

The provision of tuberculosis preventive treatment is one of the critical interventions to reduce tuberculosis incidence and ultimately eliminate the disease, yet we still miss appropriate tools for an impactful intervention and treatment coverage remains low. We used recent data, epidemiological estimates, and research findings to analyze the challenges of each step of the cascade of tuberculosis prevention that currently delay the strategy implementation. We addressed research gaps and implementation bottlenecks that withhold key actions in tuberculosis case finding, testing for tuberculosis infection, provision of preventive treatment with safer, shorter regimens and supporting people to complete their treatment. Empowering communities to generate demand for preventive therapy and other prevention services in a holistic manner and providing adequate financial support to sustain implementation are essential requirements. The adoption of an effective, universal monitoring and evaluation system is a prerequisite to provide general and granular insight, and to steer progress of the tuberculosis infection strategy at global and local level.

Mortality of children and adolescents co-infected with tuberculosis and HIV: a systematic review and meta-analysis

OBJECTIVE

Children and adolescents with HIV infection are well known to face a heightened risk of tuberculosis. However, the exact mortality rates and temporal trends of those with HIV-tuberculosis (TB) co-infection remain unclear. We aimed to identify the overall mortality and temporal trends within this population.

METHODS

PubMed, Web of Science, and Embase were employed to search for publications reporting on the mortality rates of children and adolescents with HIV-TB co-infection from inception to March 2, 2024. The outcome is the mortality rate for children and adolescents with HIV-TB co-infection during the follow-up period. In addition, we evaluate the temporal trends of mortality.

RESULTS

During the follow-up period, the pooled mortality was 16% [95% confidence interval (CI) 13-20]. Single infection of either HIV or TB exhibit lower mortality rates (6% and 4%, respectively). We observed elevated mortality risks among individuals aged less than 12 months, those with extrapulmonary TB, poor adherence to ART, and severe immunosuppression. In addition, we observed a decreasing trend in mortality before 2008 and an increasing trend after 2008, although the trends were not statistically significant ( P  = 0.08 and 0.2 respectively).

CONCLUSIONS

Children and adolescents with HIV-TB co-infection bear a significant burden of mortality. Timely screening, effective treatment, and a comprehensive follow-up system contribute to reducing the mortality burden in this population.

Mycobacterium tuberculosis Infection in School Contacts of Tuberculosis Cases: A Systematic Review and Meta-Analysis

Substantial tuberculosis transmission occurs outside of households, and tuberculosis surveillance in schools has recently been proposed. However, the yield of tuberculosis outcomes from school contacts is not well characterized. We assessed the prevalence of Mycobacterium tuberculosis infection among close school contacts by performing a systematic review. We searched PubMed, Elsevier, China National Knowledge Infrastructure, and Wanfang databases. Studies reporting the number of children who were tested overall and who tested positive were included. Subgroup analyses were performed by study location, index case bacteriological status, type of school, and other relevant factors. In total, 28 studies including 54,707 school contacts screened for M. tuberculosis infection were eligible and included in the analysis. Overall, the prevalence of M. tuberculosis infection determined by the QuantiFERON Gold in-tube test was 33.2% (95% CI, 0.0-73.0%). The prevalences of M. tuberculosis infection based on the tuberculin skin test (TST) using 5 mm, 10 mm, and 15 mm as cutoffs were 27.2% (95% CI, 15.1-39.3%), 24.3% (95% CI, 15.3-33.4%), and 12.7% (95% CI, 6.3-19.0%), respectively. The pooled prevalence of M. tuberculosis infection (using a TST ≥5-mm cutoff) was lower in studies from China (22.8%; 95% CI, 16.8-28.8%) than other regions (36.7%; 95% CI, 18.1-55.2%). The pooled prevalence of M. tuberculosis infection was higher when the index was bacteriologically positive (43.6% [95% CI, 16.5-70.8%] versus 23.8% [95% CI, 16.2-31.4%]). These results suggest that contact investigation and general surveillance in schools from high-burden settings merit consideration as means to improve early case detection in children.

Genetic and clinical predictors of rifapentine and isoniazid pharmacokinetics in paediatrics with tuberculosis infection

OBJECTIVES

Twelve weekly doses of rifapentine and isoniazid (3HP regimen) are recommended for TB preventive therapy in children with TB infection. However, they present with variability in the pharmacokinetic profiles. The current study aimed to develop a pharmacokinetic model of rifapentine and isoniazid in 12 children with TB infection using NONMEM.

METHODS

Ninety plasma and 41 urine samples were collected at Week 4 of treatment. Drug concentrations were measured using a validated HPLC-UV method. MassARRAY® SNP genotyping was used to investigate genetic factors, including P-glycoprotein (ABCB1), solute carrier organic anion transporter B1 (SLCO1B1), arylacetamide deacetylase (AADAC) and N-acetyl transferase (NAT2). Clinically relevant covariates were also analysed.

RESULTS

A two-compartment model for isoniazid and a one-compartment model for rifapentine with transit compartment absorption and first-order elimination were the best models for describing plasma and urine data. The estimated (relative standard error, RSE) of isoniazid non-renal clearance was 3.52 L·h-1 (23.1%), 2.91 L·h-1 (19.6%), and 2.58 L·h-1 (20.0%) in NAT2 rapid, intermediate and slow acetylators. A significant proportion of the unchanged isoniazid was cleared renally (2.7 L·h-1; 8.0%), while the unchanged rifapentine was cleared primarily through non-renal routes (0.681 L·h-1; 3.6%). Participants with the ABCB1 mutant allele had lower bioavailability of rifapentine, while food prolonged the mean transit time of isoniazid.

CONCLUSIONS

ABCB1 mutant allele carriers may require higher rifapentine doses; however, this must be confirmed in larger trials. Food did not affect overall exposure to isoniazid and only delayed absorption time.

Pediatric Tuberculosis: A Review of Evidence-Based Best Practices for Clinicians and Health Care Providers

Advances in pediatric TB care are promising, the result of decades of advocacy, operational and clinical trials research, and political will by national and local TB programs in high-burden countries. However, implementation challenges remain in linking policy to practice and scaling up innovations for prevention, diagnosis, and treatment of TB in children, especially in resource-limited settings. There is both need and opportunity to strengthen clinician confidence in making a TB diagnosis and managing the various manifestations of TB in children, which can facilitate the translation of evidence to action and expand access to new tools and strategies to address TB in this population. This review aims to summarize existing guidance and best practices for clinicians and health care providers in low-resource, TB-endemic settings and identify resources with more detailed and actionable information for decision-making along the clinical cascade to prevent, find, and cure TB in children.

Routine tuberculosis contact investigation yield and preventive treatment cascade in central Ethiopia

Introduction

There is a global gap between tuberculosis incident cases and the notified cases. Active household contact investigation is one of the strategies to narrow this gap. It has the advantage of giving early diagnosis and preventive treatment to vulnerable and eligible groups. This study assessed the practice of contact investigation and tuberculosis preventive treatment adherence in central Ethiopia.

Method

A cross-sectional study covering all registered bacteriologically confirmed pulmonary tuberculosis patients and their close contacts was conducted in central Ethiopia from January 1, 2022, to December 30, 2022.

Result

A total of 1372 household contacts were declared by the index cases. From these 79.44 % (1090) contacts received a one-time tuberculosis screening giving a total of four (0.36 %) active TB cases. Among 484 household contacts of drug-resistant tuberculosis index cases, 5.53 % (14) had presumptive tuberculosis and 0.79 % (2) had active tuberculosis. While among 837 household contacts of drug-susceptible tuberculosis index cases presumptive TB cases were 1.91 % (16) and active TB cases were 0.23 % (2). Of the 142 eligible under 15 children 81.69 % (116) had started tuberculosis preventive treatment and 84.48 % (98) completed the treatment. On multivariable logistic regression, the associated factor for tuberculosis preventive treatment non-adherence was age 2-5 years (aOR, 0.02, 95 % CI (0.002-0.20) and age 5-15 years (aOR, 0.04,95 % CI (0.002-0 0.95)) P=<0.05).

Conclusion

There was low contact screening practice in the DR-TB index cases as compared to national and global targets. The yield of routine contact investigation was low and it indicates the quality of screening. Tuberculosis preventive treatment initiation and completion rates were also low as compared to those of many other countries and global achievements which need further improvement, especially for completion. Alternative mechanisms should be planned to increase the yield of tuberculosis screening and tuberculosis preventive treatment adherence.

Determinants of tuberculosis disease development in children in central Ethiopia: A matched case-control study

BACKGROUND

The risk factors for tuberculosis (TB) disease development in children remained understudied, particularly in low-income countries like Ethiopia. The objective of this study was to identify determinants of TB disease development in general and in relation to BCG vaccination in children in central Ethiopia.

METHODS

We employed a 1:1 age-matched case-control design to compare the characteristics of children who developed TB (cases) with those who did not (controls). Data were collected in healthcare facilities in Addis Ababa city, Adama, and Bishoftu towns between September 25, 2021, and June 24, 2022. Two hundred and fifty-six cases were drawn at random from a list of childhood TB patients entered into SPSS software, and 256 controls were selected sequentially at triage from the same healthcare facilities where the cases were treated. A bivariate conditional logistic regression analysis was performed first to select candidate variables with p-values less than or equal to 0.20 for the multivariable model. Finally, variables with a p-value less than 0.05 for a matched adjusted odds ratio (mORadj) were reported as independent determinants of TB disease development.

RESULTS

The mean age of the cases was nine years, while that of the controls was 10 years. Males comprised 126 cases (49.2%) and 119 controls (46.5%), with the remainder being females. Ninety-nine (38.7%) of the cases were not BCG-vaccinated, compared to 58 (22.7%) of the controls. Household TB contact was experienced by 43 (16.8%) of the cases and 10 (3.9%) of the controls. Twenty-two (8.6%) of the cases and six (2.3%) of the controls were exposed to a cigarette smoker in their household. Twenty-two (8.6%) of the cases and three (1.2%) of the controls were positive for HIV. Children who were not vaccinated with BCG at birth or within two weeks of birth had more than twice the odds (mORadj = 2.11, 95% CI = 1.28-3.48) of developing TB compared to those who were. Children who ever lived with a TB-sick family member (mORadj = 4.28, 95% CI = 1.95-9.39), smoking family members (mORadj = 3.15, 95% CI = 1.07-9.27), and HIV-infected children (mORadj = 8.71, 95% CI = 1.96-38.66) also had higher odds of developing TB disease than their counterparts.

CONCLUSIONS

Being BCG-unvaccinated, having household TB contact, having a smoker in the household, and being HIV-infected were found to be independent determinants of TB disease development among children.

Pharmacokinetics and Optimal Dosing of Levofloxacin in Children for Drug-Resistant Tuberculosis: An Individual Patient Data Meta-Analysis

BACKGROUND

Each year 25 000-32 000 children develop rifampicin- or multidrug-resistant tuberculosis (RR/MDR-TB), and many more require preventive treatment. Levofloxacin is a key component of RR/MDR-TB treatment and prevention, but the existing pharmacokinetic data in children have not yet been comprehensively summarized. We aimed to characterize levofloxacin pharmacokinetics through an individual patient data meta-analysis of available studies and to determine optimal dosing in children.

METHODS

Levofloxacin concentration and demographic data were pooled from 5 studies and analyzed using nonlinear mixed effects modeling. Simulations were performed using current World Health Organization (WHO)-recommended and model-informed optimized doses. Optimal levofloxacin doses were identified to target median adult area under the time-concentration curve (AUC)24 of 101 mg·h/L given current standard adult doses.

RESULTS

Data from 242 children (2.8 years [0.2-16.8] was used). Apparent clearance was 3.16 L/h for a 13-kg child. Age affected clearance, reaching 50% maturation at birth and 90% maturation at 8 months. Nondispersible tablets had 29% lower apparent oral bioavailability compared to dispersible tablets. Median exposures at current WHO-recommended doses were below the AUC target for children weighing <24 kg and under <10 years, resulting in approximately half of the exposure in adults. Model-informed doses of 16-33 mg/kg for dispersible tablets or 16-50 mg/kg for nondispersible tablets were required to meet the AUC target without significantly exceeding the median adult Cmax.

CONCLUSIONS

Revised weight-band dosing guidelines with doses of >20 mg/kg are required to ensure adequate exposure. Further studies are needed to determine safety and tolerability of these higher doses.

Maternal HIV Status and Risk of Infant Mycobacterium tuberculosis Infection as Measured by Tuberculin Skin Test

BACKGROUND

The effect of maternal HIV on infant Mycobacterium tuberculosis (Mtb) infection risk is not well-characterized.

METHODS

Pregnant women with/without HIV and their infants were enrolled in a longitudinal cohort in Kenya. Mothers had interferon gamma-release assays (QFT-Plus) and tuberculin skin tests (TST) at enrollment in pregnancy; children underwent TST at 12 and 24 months of age. We estimated the incidence and correlates of infant TST-positivity using Cox proportional hazards regression.

RESULTS

Among 322 infants, 170 (53%) were HIV-exposed and 152 (47%) were HIV-unexposed. Median enrollment age was 6.6 weeks [interquartile range (IQR): 6.1-10.0]; most received Bacillus Calmette-Guerin (320, 99%). Thirty-nine (12%) mothers were TST-positive; 102 (32%) were QFT-Plus-positive. Among HIV-exposed infants, 154 (95%) received antiretrovirals for HIV prevention and 141 (83%) of their mothers ever received isoniazid preventive therapy (IPT). Cumulative 24-month infant Mtb infection incidence was 3.6/100 person-years (PY) [95% confidence interval (CI): 2.4-5.5/100 PY]; 5.4/100 PY in HIV-exposed infants (10%, 17/170) versus 1.7/100 PY in HIV-unexposed infants (3.3%, 5/152) [hazard ratio (HR): 3.1 (95% CI: 1.2-8.5)]. More TST conversions occurred in the first versus second year of life [5.8 vs. 2.0/100 PY; HR: 2.9 (95% CI: 1.0-10.1)]. Infant TST-positivity was associated with maternal TST-positivity [HR: 2.9 (95% CI: 1.1-7.4)], but not QFT-Plus-positivity. Among HIV-exposed children, Mtb infection incidence was similar regardless of maternal IPT.

CONCLUSIONS

Mtb infection incidence (by TST) by 24 months of age was ~3-fold higher among HIV-exposed children, despite high maternal IPT uptake. Overall, more TST conversions occurred in the first 12 months compared to 12-24 months of age, similar in both HIV-exposed and HIV-unexposed children.

Community-based active-case finding for tuberculosis: navigating a complex minefield

Community-based active case finding (ACF) for tuberculosis (TB) involves an offer of screening to populations at risk of TB, oftentimes with additional health promotion, community engagement and health service strengthening. Recently updated World Health Organization TB screening guidelines conditionally recommend expanded offer of ACF for communities where the prevalence of undiagnosed pulmonary TB is greater than 0.5% among adults, or with other structural risk factors for TB. Subclinical TB is thought to be a major contributor to TB transmission, and ACF, particularly with chest X-ray screening, could lead to earlier diagnosis. However, the evidence base for the population-level impact of ACF is mixed, with effectiveness likely highly dependent on the screening approach used, the intensity with which ACF is delivered, and the success of community- and health-system participation. With recent changes in TB epidemiology due to the effective scale-up of treatment for HIV in Africa, the impacts of the COVID-19 pandemic, and the importance of subclinical TB, researchers and public health practitioners planning to implement ACF programmes must carefully and repeatedly consider the potential population and individual benefits and harms from these programmes. Here we synthesise evidence and experience from implementing ACF programmes to provide practical guidance, focusing on the selection of populations, screening algorithms, selecting outcomes, and monitoring and evaluation. With careful planning and substantial investment, community-based ACF for TB can be an impactful approach to accelerating progress towards elimination of TB in high-burden countries. However, ACF cannot and should not be a substitute for equitable access to responsive, affordable, accessible primary care services for all.

Effectiveness and safety of tuberculosis preventive treatment for contacts of patients with multidrug-resistant tuberculosis: a systematic review and meta-analysis

BACKGROUND

Contacts of patients with multidrug-resistant tuberculosis (MDR-TB) are at risk of developing TB disease. Tuberculosis preventive treatment (TPT) is an intervention that can potentially reduce this risk.

OBJECTIVES

To evaluate the effectiveness and safety of TPT for contacts of patients with MDR-TB.

DATA SOURCES

EMBASE, PubMed, Web of Science, and the Cochrane Library were searched for eligible studies on 24 July 2023, without start date restrictions.

STUDY ELIGIBILITY CRITERIA

We included studies that compared TPT with no treatment in contacts of patients with MDR-TB and reported outcomes of progression to TB disease.

PARTICIPANTS

Contacts of patients with MDR-TB.

INTERVENTIONS

TPT.

ASSESSMENT OF RISK OF BIAS

A modified version of the Newcastle-Ottawa Scale was used.

METHODS OF DATA SYNTHESIS

Random-effects meta-analysis was utilized to calculate the relative risk for disease progression to TB in contacts of patients with MDR-TB who received TPT compared to those who did not. Additionally, completion, adverse effect, and discontinued rates were assessed.

RESULTS

Involving 1105 individuals from 11 studies, the pooled relative risk for disease progression in contacts receiving TPT versus those without treatment was 0.34 (95% CI: 0.16-0.72). Subgroup analysis indicated a lower pooled relative risk for regimens based on the drug-resistance profile of the index patients with TB compared to uniform treatment regimens (0.22 [95% CI: 0.06-0.84] vs. 0.49 [95% CI: 0.17-1.35]), although not statistically significant. The pooled completed rate was 83.8%, adverse effect rate was 22.9%, and discontinued rate was 6.5%. After excluding the levofloxacin and pyrazinamide regimen study, the completed rate increased to 88.0%, and adverse effects and discontinued rates decreased to 8.0% and 4.0%, respectively.

DISCUSSION

TPT reduces TB disease progression risk in contacts of patients with MDR-TB. Tailored TPT regimens based on drug-resistance profiles may offer additional benefits. Furthermore, efforts to improve completed rates and manage adverse effects are essential for optimizing effectiveness and safety.

The Impact of Preventive Treatment for Multidrug- and Rifampin-Resistant Tuberculosis Exceeds Trial-Based Estimates

BACKGROUND

Several clinical trials of tuberculosis preventive treatment (TPT) for household contacts of patients with multidrug- or rifampin-resistant tuberculosis (MDR/RR-TB) are nearing completion. The potential benefits of delivering TPT to MDR/RR-TB contacts extend beyond the outcomes that clinical trials can measure.

METHODS

We developed an agent-based, household-structured TB and MDR/RR-TB transmission model, calibrated to an illustrative setting in India. We simulated contact investigation in households of patients with MDR/RR-TB, comparing an MDR/RR-TPT regimen (assuming 6-month duration, 70% efficacy) and associated active case finding against alternatives of contact investigation without TPT or no household intervention. We simulated the TB and MDR/RR-TB incidence averted relative to placebo over 2 years, as measurable by a typical trial, as well as the incidence averted over a longer time horizon, in the broader population, and relative to no contact investigation.

RESULTS

Observing TPT and placebo recipients for 2 years as in a typical trial, MDR/RR-TPT was measured to prevent 72% (interquartile range, 45%-100%) of incident MDR/RR-TB among recipients; the median number needed to treat (NNT) to prevent 1 MDR/RR-TB case was 73, compared to placebo. This NNT decreased to 54 with 13-18 years of observation, to 27 when downstream transmission effects were also considered, and to 12 when the effects of active TB screening were included by comparing to a no-household-contact-intervention scenario.

CONCLUSIONS

If forthcoming trial results demonstrate efficacy, the long-term population impact of TPT for MDR/RR-TB-including the large effect of increased active TB detection among MDR/RR-TB contacts-could be much greater than suggested by trial outcomes alone.

Causal relationship between gut microbiota and tuberculosis: a bidirectional two-sample Mendelian randomization analysis

BACKGROUND

Growing evidence from observational studies and clinical trials suggests that the gut microbiota is associated with tuberculosis (TB). However, it is unclear whether any causal relationship exists between them and whether causality is bidirectional.

METHODS

A bidirectional two-sample Mendelian randomization (MR) analysis was performed. The genome-wide association study (GWAS) summary statistics of gut microbiota were obtained from the MiBioGen consortium, while the GWAS summary statistics of TB and its specific phenotypes [respiratory tuberculosis (RTB) and extrapulmonary tuberculosis (EPTB)] were retrieved from the UK Biobank and the FinnGen consortium. And 195 bacterial taxa from phylum to genus were analyzed. Inverse variance weighted (IVW), MR-Egger regression, maximum likelihood (ML), weighted median, and weighted mode methods were applied to the MR analysis. The robustness of causal estimation was tested using the heterogeneity test, horizontal pleiotropy test, and leave-one-out method.

RESULTS

In the UK Biobank database, we found that 11 bacterial taxa had potential causal effects on TB. Three bacterial taxa genus.Akkermansia, family.Verrucomicrobiacea, order.Verrucomicrobiales were validated in the FinnGen database. Based on the results in the FinnGen database, the present study found significant differences in the characteristics of gut microbial distribution between RTB and EPTB. Four bacterial taxa genus.LachnospiraceaeUCG010, genus.Parabacteroides, genus.RuminococcaceaeUCG011, and order.Bacillales were common traits in relation to both RTB and TB, among which order.Bacillales showed a protective effect. Additionally, family.Bacteroidacea and genus.Bacteroides were identified as common traits in relation to both EPTB and TB, positively associating with a higher risk of EPTB. In reverse MR analysis, no causal association was identified. No significant heterogeneity of instrumental variables (IVs) or horizontal pleiotropy was found.

CONCLUSION

Our study supports a one-way causal relationship between gut microbiota and TB, with gut microbiota having a causal effect on TB. The identification of characteristic gut microbiota provides scientific insights for the potential application of the gut microbiota as a preventive, diagnostic, and therapeutic tool for TB.

QuantiFERON Gold-In-Tube for the diagnosis of mycobacterial tuberculosis infection in children under 5 years of age: A systematic review and meta-analysis

BACKGROUND

Previous meta-analysis regarding the performance of QuantiFERON Gold-In-Tube in children have yielded contrasting results. Emerging data in children younger than 5 years of age necessitates a new analysis.

METHODS

Systematic searches were conducted of MedLINE, EMBASE and Cochrane databases between 1998-2023. Pooled estimates of sensitivities and specificities of QFT-GIT compared to tuberculin skin test (TST) were calculated. The Kappa (k) coefficient was calculated for each study to determine the degree of congruence between TST and QFT-GIT results. Studies including patients co-infected with HIV or other immune compromising conditions or those treated with anti-tubercular treatment were excluded.

RESULTS

Seventeen studies (4335 patients) were included in quantitative analysis. All studies were conducted in middle to high income countries. They were conducted across 14 countries and 4 studies in countries with high TB incidence. The pooled sensitivity, specificity and DOR were 0.45 (0.42-0.48), 0.96 (0.96-0.97) and 18.84 (7.33-48.41) respectively. The ability of QFT-GIT to discriminate with disease and no disease was "good" as demonstrated by a summary receiver operating characteristic curve with area under curve of 0.7812. The average Kappa (k) co-efficient was 0.501 with a wide variety of values between studies (0.167 to 0.800).

CONCLUSION

The findings of this meta-analysis support the judicious use of QFT-GIT in children 5 years and under, with caution as a sole test to exclude Tuberculosis in this age group. The heterogeneity and methodological quality of diagnostic studies limits the generalisability of results.

Timeliness metrics for screening and preventing TB in household contacts of pulmonary TB patients in Kenya

BACKGROUND

The study assessed whether a "7-1-7" timeliness metric for screening and TB preventive therapy (TPT) could be implemented for household contacts (HHCs) of index patients with bacteriologically confirmed pulmonary TB under routine programmatic settings in Kenya.

METHODS

A longitudinal cohort study conducted among index patients and their HHCs in 12 health facilities, Kiambu County, Kenya.

RESULTS

Between January and June 2023, 95% of 508 index patients had their HHCs line-listed within 7 days of initiating anti-TB treatment ("First 7"). In 68% of 1,115 HHCs, screening outcomes were ascertained within 1 day of line-listing ("Next 1"). In 65% of 1,105 HHCs eligible for further evaluation, anti-TB treatment, TPT or a decision for no drugs was made within 7 days of screening ("Second 7"). Altogether, 62% of screened HHCs started TPT during the "7-1-7" period compared with 58% in a historical cohort. Main barriers to TPT uptake were HHCs not consulting clinicians, HHCs being unwilling to initiate TPT and drug shortages. Healthcare workers felt that a timeliness metric was valuable for streamlining HHC management and proposed "3-5-7" as a workable alternative.

CONCLUSIONS

The national TB programme must generate awareness about TPT, ensure uninterrupted drug supplies and assess whether the "3-5-7" metric can be operationalised.

Incidence and risk factors of tuberculosis among 420 854 household contacts of patients with tuberculosis in the 100 Million Brazilian Cohort (2004-18): a cohort study

BACKGROUND

Although household contacts of patients with tuberculosis are known to be particularly vulnerable to tuberculosis, the published evidence focused on this group at high risk within the low-income and middle-income country context remains sparse. Using nationwide data from Brazil, we aimed to estimate the incidence and investigate the socioeconomic and clinical determinants of tuberculosis in a cohort of contacts of tuberculosis patients.

METHODS

In this cohort study, we linked individual socioeconomic and demographic data from the 100 Million Brazilian Cohort to mortality data and tuberculosis registries, identified contacts of tuberculosis index patients diagnosed from Jan 1, 2004 to Dec 31, 2018, and followed up the contacts until the contact's subsequent tuberculosis diagnosis, the contact's death, or Dec 31, 2018. We investigated factors associated with active tuberculosis using multilevel Poisson regressions, allowing for municipality-level and household-level random effects.

FINDINGS

We studied 420 854 household contacts of 137 131 tuberculosis index patients. During the 15 years of follow-up (median 4·4 years [IQR 1·9-7·6]), we detected 8953 contacts with tuberculosis. The tuberculosis incidence among contacts was 427·8 per 100 000 person-years at risk (95% CI 419·1-436·8), 16-times higher than the incidence in the general population (26·2 [26·1-26·3]) and the risk was prolonged. Tuberculosis incidence was associated with the index patient being preschool aged (<5 years; adjusted risk ratio 4·15 [95% CI 3·26-5·28]) or having pulmonary tuberculosis (2·84 [2·55-3·17]).

INTERPRETATION

The high and sustained risk of tuberculosis among contacts reinforces the need to systematically expand and strengthen contact tracing and preventive treatment policies in Brazil in order to achieve national and international targets for tuberculosis elimination.

FUNDING

Wellcome Trust and Brazilian Ministry of Health.

Patterns of childhood tuberculosis diagnosis in Ethiopia: A multicenter cross-sectional study

Background

Children share 12% of the global 10 million people infected with tuberculosis (TB) each year. Closing case detection gap in children remains difficult, with 56% of all children and 65% under-five with TB missed each year. We aimed to assess the patterns of childhood TB diagnosis and underlying determinants in Ethiopia when different TB diagnostic platforms are applied.

Methods

A multi-site, cross-sectional study was carried out in Ethiopia as part of the larger EXIT-TB study - evidence-based multiple focused integrated intensified TB screening package. Outpatient children aged ≤ 15 with cough of any duration seeking care at four healthcare facilities in Ethiopia were enrolled consecutively. Participants underwent sputum Xpert MTB/RIF and/or smear microscopy and posteroanterior chest X-ray (CXR), and their clinical and sociodemographic data were captured using a structured questionnaire. Data were analyzed using Stata version 23. Multiple regression model was computed to determine the factors that influence TB case detection, with a 95% confidence interval (CI) and p < 0.05 taken as statistically significant.

Results

A total of 438 children were enrolled. Of these, 399 had CXR examination of which 55 (13.8%) were suggestive of TB, 270 had Xpert MTB/RIF testing of which 32 (11.9%) were positive, and AFB smear microscopy was done for 51 children of which 2 (3.9%) were positive. Febrile children were more likely to be diagnosed with pulmonary TB than those without fever [aPR = 1.3, 95% CI (1.1-1.4)], and those with a TB contact history were more likely to be diagnosed with pulmonary TB than those with no such contacts [aPR = 1.2, 95% CI (1.1-1.3)]. Children from rural residences were more likely to be diagnosed with TB than those from urban residences [aPR = 1.3, 95% CI (1.1-1.5)].

Conclusion

The findings showed that clinical diagnosis remains an important method of TB diagnosis in children and the preferred choice to avert underdiagnosis. A more sensitive TB diagnostic method for children was symptom screening, followed by CXR and Xpert MTB/RIF assay or smear microscopy. Hence, an algorithm that combines clinical, CXR, and microbiological confirmatory tests can improve the rate of pulmonary TB diagnosis in children till more accurate and cost-effective diagnostic tools are accessible. Fever, weight loss, and TB contact history are highly associated with TB positivity rates in children.

The role of Xpert MTB/RIF using bronchoalveolar lavage fluid in active screening: insights from a tuberculosis outbreak in a junior school in eastern China

Background

Tuberculosis (TB) outbreaks in schools present a public health challenge. In order to effectively control the spread of transmission, timely screening, accurate diagnosis and comprehensive epidemiological investigations are essential.

Methods

In July 2021, a TB outbreak occurred in a junior high school in Y City, Zhejiang Province. Students and faculty were screened for TB by symptom screening, chest radiography, and tuberculin skin test during four rounds of contact screenings. For sputum smear-negative and sputum-scarce patients, bronchoscopy was used to collect BAL samples for Xpert Mycobacterium tuberculosis/rifampin (MTB/RIF). Whole-genome sequencing and bioinformatics analysis were performed on isolates to identify the strains of MTB isolates and predict drug resistance.

Results

Between July 2021 and November 2021, a total of 1,257 students and faculty were screened for TB during screenings. A total of 15 students (1.2% of persons screened) aged 15 years were diagnosed with TB. Eighty percent (12/15) of the cases were laboratory-confirmed (10/12 [83%] Xpert MTB/RIF-positive, 2/12 [17%] culture-positive). Most cases (12/15 [80%]) were in students from Class 2. All cases were asymptomatic except for the index case who had symptoms for more than two months. Seven MTB isolates were collected and belonged to lineage 2.

Conclusion

Our findings demonstrated the potential of Xpert MTB/RIF using BAL as a screening tool in school TB outbreaks for sputum smear-negative and sputum-sparse suspects, which may not only rapidly improves diagnostic accuracy, but also facilitates epidemiological investigations and homology analysis.