Burden of childhood tuberculosis in 22 high-burden countries: a mathematical modelling study

Safety of first year vaccination in children born to mothers with inflammatory bowel disease and exposed in utero to anti-TNFα agents: a French nationwide population-based cohort

BACKGROUND

Children born to mothers with IBD may be exposed to anti-TNFα agents antenatally. Current European guidelines recommend postponing live vaccines until after 6 months of life in this population. Data on the safety of live vaccines administration in the first year of life of these children are sparse with one reported fatality following bacillus Calmette-Guerin (BCG) administration.

AIMS

To describe the use and safety of vaccines administered in children born to mothers with IBD and exposed antenatally to anti-TNFα agents METHODS: Data from children born to mothers with IBD between 2013 and 2014 were collected retrospectively from the French Health Insurance Database. Vaccines recommended before or at 1 year of age were considered.

RESULTS

Among 4741 children, 670 (14.1%) were exposed to anti-TNFα agents antenatally, with concomitant thiopurines in 16.0% (n = 107) and steroids in 19.3% (n = 214). Among these 670 children, 315 (47%) were exposed up to delivery. Exposed children were less likely than non-exposed to receive BCG (88/670, 13.1% vs 780/4071, 19.2% respectively, P < .05) and received it later in life (months, mean ± SD, 4.3 ± 3.9 and 2.4 ± 2.9 respectively, P < .001). In exposed children, 64/88 (73%) received BCG vaccination before 6 months of age, but with no BCG-related severe adverse event observed during the first year. Uptake of other vaccines recommended before 6 months was above 85% in both groups.

CONCLUSION

In children exposed antenatally to anti-TNFα agents, vaccinations are often not postponed in keeping with the recommendations, but no BCG-related severe adverse events were reported in children vaccinated before 6 months of life.

Profiling Mycobacterium tuberculosis transmission and the resulting disease burden in the five highest tuberculosis burden countries

BACKGROUND

Tuberculosis (TB) control efforts are hampered by an imperfect understanding of TB epidemiology. The true age distribution of disease is unknown because a large proportion of individuals with active TB remain undetected. Understanding of transmission is limited by the asymptomatic nature of latent infection and the pathogen's capacity for late reactivation. A better understanding of TB epidemiology is critically needed to ensure effective use of existing and future control tools.

METHODS

We use an agent-based model to simulate TB epidemiology in the five highest TB burden countries-India, Indonesia, China, the Philippines and Pakistan-providing unique insights into patterns of transmission and disease. Our model replicates demographically realistic populations, explicitly capturing social contacts between individuals based on local estimates of age-specific contact in household, school and workplace settings. Time-varying programmatic parameters are incorporated to account for the local history of TB control.

RESULTS

We estimate that the 15-19-year-old age group is involved in more than 20% of transmission events in India, Indonesia, the Philippines and Pakistan, despite representing only 5% of the local TB incidence. According to our model, childhood TB represents around one fifth of the incident TB cases in these four countries. In China, three quarters of incident TB were estimated to occur in the ≥ 45-year-old population. The calibrated per-contact transmission risk was found to be similar in each of the five countries despite their very different TB burdens.

CONCLUSIONS

Adolescents and young adults are a major driver of TB in high-incidence settings. Relying only on the observed distribution of disease to understand the age profile of transmission is potentially misleading.

Treatment of Drug-Resistant Tuberculosis. An Official ATS/CDC/ERS/IDSA Clinical Practice Guideline

Background: The American Thoracic Society, U.S. Centers for Disease Control and Prevention, European Respiratory Society, and Infectious Diseases Society of America jointly sponsored this new practice guideline on the treatment of drug-resistant tuberculosis (DR-TB). The document includes recommendations on the treatment of multidrug-resistant TB (MDR-TB) as well as isoniazid-resistant but rifampin-susceptible TB.Methods: Published systematic reviews, meta-analyses, and a new individual patient data meta-analysis from 12,030 patients, in 50 studies, across 25 countries with confirmed pulmonary rifampin-resistant TB were used for this guideline. Meta-analytic approaches included propensity score matching to reduce confounding. Each recommendation was discussed by an expert committee, screened for conflicts of interest, according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology.Results: Twenty-one Population, Intervention, Comparator, and Outcomes questions were addressed, generating 25 GRADE-based recommendations. Certainty in the evidence was judged to be very low, because the data came from observational studies with significant loss to follow-up and imbalance in background regimens between comparator groups. Good practices in the management of MDR-TB are described. On the basis of the evidence review, a clinical strategy tool for building a treatment regimen for MDR-TB is also provided.Conclusions: New recommendations are made for the choice and number of drugs in a regimen, the duration of intensive and continuation phases, and the role of injectable drugs for MDR-TB. On the basis of these recommendations, an effective all-oral regimen for MDR-TB can be assembled. Recommendations are also provided on the role of surgery in treatment of MDR-TB and for treatment of contacts exposed to MDR-TB and treatment of isoniazid-resistant TB.

Impact of negative tuberculin skin test on growth among disadvantaged Bangladeshi children

Millions of children are suffering from tuberculosis (TB) worldwide and often end-up with fatal outcome especially in resource-poor settings. Tuberculin skin test (TST) is a conventionally used diagnostic test, less sensitive but highly specific for the diagnosis of clinical TB especially in undernourished children. However, we do not have any data on the role of TST positivity among the children who received nutritional intervention. Our aim was to examine the growth differences between TST-positive and TST-negative undernourished children aged 12 to 18 months who received nutritional intervention prospectively for 90 feeding days. Our further aim was to explore the determinants of TST positivity at enrollment. TB screening as one of the secondary causes of malnutrition was performed on 243 stunted [length for age Z score (LAZ) <-2 standard deviations] or at-risk of stunting (LAZ score between <-1 and -2 standard deviations) children in a community-based intervention study designed to improve their growth parameters. Differences of growth between TST-positives (n = 29) and TST-negatives (n = 214) were compared using paired samples t-test and multivariable linear regression from anthropometric data collected before and after nutritional intervention. Multivariable logistic regression was used to find out possible predictors of TST positivity using baseline sociodemographic data. Of the 243 children screened, 29 (11.9%) were TST-positive and 11 (4.5%) had clinically diagnosed pulmonary TB. Statistically significant improvement of LAZ and weight for age Z-score (WAZ) were observed among the TST-negative participants at the end of intervention period (p = 0.03 for LAZ and p = 0.01 for WAZ). However, we did not find any association between TST status and response to nutritional intervention in our multivariable linear regression models. Our study findings demonstrated a positive impact of nutritional intervention on growth parameters among TST-negative participants.

Demographic profile, clinical and microbiological predictors of mortality amongst admitted pediatric TB patients in a tertiary referral tuberculosis hospital

BACKGROUND

Pediatric tuberculosis (TB) constitutes 8% of the total caseload of TB. Children are particularly vulnerable to dissemination of disease and mortality.

AIM

To determine mortality rate, elucidate type of TB, causes and predictors of mortality, if any, in admitted pediatric TB patients.

METHODS

Present retrospective study was conducted in a tertiary referral center over last 6½ year on children who died out of total TB admissions.

RESULTS

Out of total 1380 pediatric (<15 years of age) TB admissions, 74 children died, a mortality rate of 5.36%. Mean age was 11.4 years with highest mortality 47 (63.51%) in patients from 11 to 14 years age group. Significant majority 58 (78.38%) patients were females (p < 0.011). Range of hospital stay was 0-113 days with 7 (9.5%), 9 (12.16%) and 27 (36.48%) children dying on day of admission, next day and 3rd-7th day respectively, therefore a total of 43 (58.11%) died within first week of admission. Most 60 (81.08%) patients belonged to poor socio-economic status. History of contact was present in 12 (16.22%) cases while none had diabetes. 31 (41.89%) patients had sepsis and severe anemia (Hb ≤ 6 g %) was present in 6 (8.11%) patients at admission, out of which 4 died on the same day of admission, even before blood could be arranged. Most patients 68 (91.89%) had pulmonary TB with 25 children having concomitant extrapulmonary involvement, while 4 (5.41%) had meningeal TB and 2 (2.70%) had disseminated TB with HIV. Microbiological confirmation was achieved in 51 (68.92%) (48 PTB and 3 EPTB) cases while 23 (31.08%) were clinically diagnosed. Bilateral extensive fibro-cavitary disease with infiltrations was the commonest. Drug resistance was confirmed in 21 (28.38%) with 2, 5, 8, 5 and 1 patient diagnosed with mono H, RR, MDR, pre-XDR and XDR respectively but results of 9 patients were received posthumously. Treatment given was category 1, category 2 and regimens for drug resistant TB in 24 (32.43%), 29 (39.19%) and 21 (28.37%) cases respectively based on prior history of ATT and drug sensitivity. Adverse drug reactions were noted in 12 (16.21%) cases. Noted immediate causes of mortality were cardio-respiratory failure, sudden pneumothorax, massive hemoptysis, sepsis, extensive pulmonary disease and aspiration pneumonia. The pointers towards mortality include female gender, severe malnutrition, anemia, extensive disseminated disease and drug resistant TB. Ignorance, dependency of children on parents, poor adherence and late referrals into the system lead to delayed diagnosis and initiation of proper regimen based treatment.

CONCLUSION

Early referrals of non-responders and failures to centers equipped with programmatic management facilities are essential for proper, timely management of pediatric TB to reduce mortality.

Risk factors for unsuccessful tuberculosis treatment outcomes in children

OBJECTIVE

Pakistan has a high pediatric burden of tuberculosis, but few studies describe the treatment experience of children with tuberculosis in Pakistan. We sought to identify risk factors for unsuccessful treatment outcomes in children with drug-susceptible tuberculosis identified in eight hospitals in Karachi, Pakistan.

DESIGN

We conducted a retrospective cohort study among children (<15 years old) treated with first-line anti-tuberculosis drugs for presumed or confirmed drug-susceptible tuberculosis between 2016 and 2017. We assessed risk factors for experiencing an unsuccessful treatment outcome through multivariable logistic regression analysis.

RESULTS

In total, 1,665 children initiated tuberculosis treatment, including 916 (55.0%) identified through intensified case finding. Unsuccessful treatment outcomes were experienced by 197 (11.8%) children, comprising 27 (1.6%) deaths, 16 (1.0%) treatment failures, and 154 (9.3%) lost to follow-up. An additional 47 (2.8%) children had outcomes not evaluable. In multivariable analysis, children 0-4 years old (OR: 1.80, 95% CI: 1.07-3.04), males (OR: 1.48, 95% CI: 1.04, 2.11), and those with bacteriologic confirmation of disease (OR: 3.39, 95% CI: 1.98, 5.80) had increased odds of experiencing an unsuccessful treatment outcome.

CONCLUSION

Our findings suggest a need to deploy strategies to identify children earlier in the disease process and point to the need for interventions tailored for young children once treatment is initiated.

Prevalence of multidrug-resistant tuberculosis in suspected childhood tuberculosis in Shandong, China: a laboratory-based study

Objective

Currently, the prevalence of multidrug-resistant tuberculosis (MDR-TB) in childhood tuberculosis (TB) in Shandong, China remains unclear. We retrospectively conducted laboratory-based surveillance in a high TB burden district, to analyze the local prevalence of MDR-TB in childhood TB.

Methods

We collected data, including microbiological results and demographic and disease information, using a questionnaire and medical records. We used the chi-squared test to compare the prevalence of MDR-TB in childhood TB between two periods: 2008 to 2013 and 2014 to 2018.

Results

In Shandong, the prevalence of MDR-TB in childhood TB was low, at 5.6%. Between 2008-2013 and 2014-2018 among children with TB, the prevalence of MDR-TB remained unchanged, the proportion with pulmonary TB decreased from 78.3% to 64.9%, and the proportion with a TB contact history decreased from 20.5% to 9.9%.

Conclusions

The prevalence of MDR-TB among childhood TB in Shandong, China was low and has remained stable over the past years. However, non-tuberculous mycobacterial diseases may be a new challenge in the management of suspected childhood TB.

Clinical and epidemiological features of tuberculosis in children and adolescents

OBJECTIVE

To analyze the clinical and epidemiological features of tuberculosis in children and adolescents in an infectious diseases reference hospital.

METHOD

A documental and retrospective study was carried out with 88 medical files in an infectious diseases reference hospital in the state of Ceará. Data were analyzed by univariate, bivariate and multivariate approaches.

RESULTS

It was found that, depending on the tuberculosis type, its manifestations may vary. The logistic regression model considered only pulmonary tuberculosis due to a number of observations and included female sex (95% CI: 1.4-16.3), weight loss (95% CI: 1.8-26.3), bacilloscopic screening (95% CI: 1.5-16.6) and sputum collected (95% CI: 1.4-19.4) as possible predictors.

CONCLUSIONS

Children and adolescents present different manifestations of the disease depending on the tuberculosis type that affects them. Knowing the most common features of each condition could enhance early diagnosis and, consequently, result in adequate treatment and care.

Tuberculin skin test conversion and primary progressive tuberculosis disease in the first 5 years of life: a birth cohort study from Cape Town, South Africa

Background

Tuberculosis is a leading cause of global childhood mortality. However, the epidemiology and burden of tuberculosis in infancy is not well understood. We aimed to investigate tuberculin skin test conversion and tuberculosis in the Drakenstein Child Health study, a South African birth cohort in a community in which tuberculosis incidence is hyperendemic.

Methods

In this prospective birth cohort study, we enrolled pregnant women older than 18 years who were between 20 and 28 weeks' gestation and who were attending antenatal care in a peri-urban, impoverished South African setting. We followed up their children for tuberculosis from birth until April 1, 2017, or age 5 years. All children received BCG vaccination at birth. Tuberculin skin tests were administered to children at 6, 12, 24, 36, 48, and 60 months of age, and at the time of a lower respiratory tract infection. An induration reaction of 10 mm or more was considered to be a tuberculin skin test conversion. To prevent boosting, we censored children with a reactive, negative tuberculin skin test.

Findings

Among 915 mother-child pairs (201 [22%] HIV-positive mothers and two [<1%] HIV-positive children), 147 (16%) children had tuberculin skin test conversion, with increasing cumulative hazard with age (0·08 at 6 months, 0·17 at 12 months, 0·22 at 24 months, and 0·37 at age 36 months). For every 100 child-years, the incidence was 11·8 (95% CI 10·0-13·8) for tuberculin skin test conversion, 2·9 (2·4-3·7) for all diagnosed tuberculosis, and 0·7 (0·4-1·0) for microbiologically confirmed tuberculosis. Isoniazid preventive therapy was effective in averting disease progression (adjusted hazard ratio 0·22, 95% CI 0·08-0·63; p<0·0001). Children with a lower respiratory tract infection were significantly more likely to also have tuberculosis than were those without one (2·27, 1·42-3·62; p<0·0001).

Interpretation

Greater focus should be placed on the first years of life as a period of high burden of transmission and clinical expression of tuberculosis infection and disease. Multifaceted interventions, such as isoniazid preventive therapy and tuberculosis screening of infants with LRTIs, beginning early in life, are needed in high-burden settings.

Funding

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

Tuberculosis preventive treatment preferences among care givers of children in Lesotho: a pilot study

BACKGROUND

Shorter-duration regimens for preventing drug-susceptible tuberculosis (TB) have been shown to be safe and efficacious in children, and may improve acceptability, adherence, and treatment completion. While these regimens have been used in children in low TB burden countries, they are not yet widely used in high TB burden countries.

SETTING

Five health facilities in one district in Lesotho, a high TB burden country.

OBJECTIVE

Assess the preventive treatment preferences of care givers of child TB contacts.

DESIGN

Qualitative data were collected using in-depth interviews with 12 care givers whose children completed preventive treatment, and analyzed using grounded theory.

FINDINGS

Care givers were interested in being involved in the children's treatment decisions. Pill burden, treatment duration and related frequency of dosing were identified as important factors that influenced preventive treatment preferences among care givers.

CONCLUSION

Understanding care giver preferences and involving them in treatment decisions may facilitate efforts to implement successful preventive treatment for TB among children in high TB burden countries.

Low Prevalence of Latent Tuberculosis Infection among Contacts of Smear-Positive Adults in Brazil

This follow-up cross-sectional study aimed to analyze the prevalence rate and risk factors related to latent tuberculosis infection (LTBI) and active tuberculosis (TB) in children aged < 15 years in contact with adults with smear-positive pulmonary TB (PTB) in a Brazilian municipality. Data were collected from interviews, clinical evaluations, chest X-rays, tuberculin skin tests, and interferon gamma release assays. The median time elapsed between diagnosis of the index case (IC) and inclusion in the study was 2.5 years (interquartile range [IQR] = 1.5-4.4) and 7.4 years (IQR = 3.8-9.7) when we reassessed the development (or not) of active TB. The median age at the time of exposure to the IC was 6.6 years (IQR = 3.3-9.4) and 14.1 years (IQR = 8.9-17.7) at the last follow-up. Of the 99 children and adolescents in contact with smear-positive PTB, 21.2% (95% CI = 14.0-29.9) were diagnosed with LTBI, and none developed active TB. There was no statistically significant difference between the LTBI and non-LTBI groups regarding demographic, socioeconomic, and epidemiological characteristics. Unlike national and international scenarios, we found a lower frequency of LTBI and no active TB among our studied patients. For better understanding of these findings, further studies might add, among other factors, host and Mycobacterium tuberculosis genetic features.

Paediatric tuberculosis diagnosis using Mycobacterium tuberculosis real-time polymerase chain reaction assay: protocol for systematic review and meta-analysis

BACKGROUND

Tuberculosis (TB) diagnosis in children is a major challenge with up to 94% of children with TB treated empirically in TB high-burden countries. Paediatric tuberculosis (PTB) remains a major cause of morbidity and mortality globally, particularly in developing countries. Most deaths/morbidity from TB in paediatrics could be prevented with early diagnosis and appropriate treatment. The main objective of this systematic review is to examine the evidence whether real-time polymerase chain reaction assay could be the most accurate clinical laboratory diagnostic methodology for the Mycobacterium tuberculosis (MTB) detection in paediatrics.

METHODS

We will search MEDLINE/PubMed, EMBASE, BIOSIS, LILACS, Cochrane Infectious Diseases Group Specialised Register (CIDG SR), Global Health, and CINAHL for published studies that recruited children less than 16 years of age being investigated for Mycobacterium tuberculosis (MTB) infection using real-time polymerase chain reaction assay accompanied by mycobacteriological culture investigation as the reference standard. There will be no restriction regarding the language, date of publication, and publication status. We will include randomised controlled trials and observational studies (cohort, cross-sectional) in the review. Selection of studies, data extraction and management, assessment of risk of bias, and quality of evidence will be performed by two independent reviewers (EB and BC). A third researcher will be consulted in case of discrepancies. Depending on the availability and quality of the data, a meta-analysis will be performed. Otherwise, findings will be qualitatively reported.

DISCUSSION

To our knowledge, this is the first systematic review and meta-analysis assessing the detection of MTB from all clinical sample types using real-time polymerase chain reaction assay in paediatric population. This review will make available evidence on the accuracy, approach, and interpretation of results of this assay in the context of MTB diagnosis which will meet an urgent need, considering the challenges of MTB diagnosis in paediatrics.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018104052.

Childhood tuberculosis and treatment outcomes in Accra: a retrospective analysis

BACKGROUND

Tuberculosis (TB) is a leading cause of death in children and adults. Unlike for adults, there is paucity of data on childhood TB in several countries in Africa. The study objective was to assess the characteristics and treatment outcomes of children with TB from multiple health facilities in Accra, Ghana.

METHODS

A retrospective analyses was conducted using secondary data on children less than 15 years collected from 11 facilities during a TB case finding initiative in Accra from June 2010 to December 2013. Demographic and clinical characteristics as well as treatment outcomes were assessed. Multivariable logistic regression was conducted to assess predictors of mortality.

RESULTS

Out of the total 3704 TB cases reported, 5.9% (219) consisted of children with a female: male ratio of 1:1.1. Children less than 5 years made up 56.2% of the patients while 44.2% were HIV positive. The distribution of TB type were as follows: smear positive pulmonary TB (SPPTB), 46.5%, clinically diagnosed pulmonary TB 36.4%.%, extra-pulmonary TB 17.4%. Among the 214 children (97.7%) for whom treatment outcome was documented, 194 (90.7%) were successfully treated consisting of 81.3% who completed treatment and 9.4% who were cured. Eighteen children (8.4%) died. Mortality was significantly higher among the 1-4 year group (p < 0.001), those with SPPTB (p < 0.001) and HIV positive children (p < 0.001). In logistic regression, SPPTB and HIV positivity were predictors of mortality.

CONCLUSION

The proportion of children in Accra successfully treated for TB met the target of END TB Strategy treatment success indicator. HIV positivity was a risk factor for death. Reducing mortality in TB-HIV co-infected children will further improve treatment outcomes of children with TB in Accra.

Tuberculous meningitis in children: Clinical management & outcome

Although the occurrence of tuberculous meningitis (TBM) in children is relatively rare, but it is associated with higher rates of mortality and severe morbidity. The peak incidence of TBM occurs in younger children who are less than five years of age, and most children present with late-stage disease. Confirmation of diagnosis is often difficult, and other infectious causes such as bacterial, viral and fungal causes must be ruled out. Bacteriological confirmation of diagnosis is ideal but is often difficult because of its paucibacillary nature as well as decreased sensitivity and specificity of diagnostic tests. Early diagnosis and management of the disease, though difficult, is essential to avoid death or neurologic disability. Hence, a high degree of suspicion and a combined battery of tests including clinical, bacteriological and neuroimaging help in diagnosis of TBM. Children diagnosed with TBM should be managed with antituberculosis therapy (ATT) and steroids. There are studies reporting low concentrations of ATT, especially of rifampicin and ethambutol in cerebrospinal fluid (CSF), and very young children are at higher risk of low ATT drug concentrations. Further studies are needed to identify appropriate regimens with adequate dosing of ATT for the management of paediatric TBM to improve treatment outcomes. This review describes the clinical presentation, investigations, management and outcome of TBM in children and also discusses various studies conducted among children with TBM.

Management of Latent Tuberculosis Infection in Children from Developing Countries

Tuberculosis (TB), once widely prevalent throughout the world, experienced falling incidence rates in early twentieth century in developed nations, even before the introduction of anti-TB drugs, attributed to improved hygiene and living conditions. Active TB may develop following fresh infection or activation of latent tuberculosis infection (LTBI). LTBI is a state of persistent bacterial viability, however, the host stays asymptomatic and there is no evidence of clinically active tuberculosis. Therefore, treatment of all LTBI is considered as one of the ways to control tuberculosis. Diagnosis of LTBI relies on presence of immune-reactivity to TB antigen and commonly used tests include tuberculin skin test and interferon gamma release assay (IGRA). At present there is no diagnostic test that can identify an individual with LTBI who will progress to develop active disease or remain asymptomatic. Therefore, it is unclear whom to treat. In the current scenario, treatment for LTBI is restricted to high risk groups which include under-5 y contacts of adults with pulmonary TB. Various regimens for treatment of LTBI are evolving and consist of isoniazid (INH) alone for 6-9 mo or combination of INH and rifampicin for 3-4 mo or once a week combination of rifapentin and INH for 3 mo. There is a need for research to identify LTBI, risk factors for progression of LTBI to active disease and a shorter regimen for treatment.

Alternative dosing guidelines to improve outcomes in childhood tuberculosis: a mathematical modelling study

BACKGROUND

Malnourished and young children are particularly susceptible to severe forms of tuberculosis and poor treatment response. WHO dosing guidelines for drugs for tuberculosis treatment are based only on weight, which might lead to systematic underdosing and poor outcomes in these children. We aimed to assess and quantify the population effect of WHO guidelines for drug-susceptible tuberculosis in children in the 20 countries with the highest disease burden.

METHODS

We used an integrated model that linked country-specific demographic data at the individual level from the 20 countries with the highest disease burden to pharmacokinetic, outcome, and epidemiological models. We estimated tuberculosis treatment outcomes in children younger than 5 years following WHO guidelines (children are dosed by weight bands corresponding to the number of fixed-dose combination tablets [75 mg rifampicin, 50 mg isoniazid, 150 mg pyrazinamide]) and two alternative dosing strategies: one based on a proposed algorithm that uses age, weight, and available formulations, in which underweight children would receive the same drug doses as would normal weight children of the same age; and another based on an individualised algorithm without dose limitations, in which derived doses results in target exposure attainment for the typical child.

FINDINGS

We estimated that 57 234 (43%) of 133 302 children younger than 5 years who were treated for tuberculosis in 2017 were underdosed with WHO dosing and only 47% of children would reach the rifampicin exposure target. Underdosing and subtherapeutic exposures were more common among malnourished children than among age-matched healthy children. The proposed dosing approach improved estimated rifampicin target exposure attainment to 62% and equalised outcomes by nutritional status. An estimated third of unfavourable treatment outcomes might be resolved with this dosing strategy, saving the lives of a minimum of 2423 children in these countries annually. With individualised dosing approaches, almost all children could achieve adequate exposure for cure.

INTERPRETATION

This work shows that a simple change in dosing procedure to include age and nutritional status, requiring no additional measurements or new drug formulations, is one approach to improve tuberculosis treatment outcomes in children, especially malnourished children who are at high risk of mortality.

FUNDING

Eunice Kennedy Shriver National Institute of Child Health and Human Development and UK Medical Research Council.

Examining the Complex Relationship Between Tuberculosis and Other Infectious Diseases in Children

Millions of children are exposed to tuberculosis (TB) each year, many of which become infected with Mycobacterium tuberculosis. Most children can immunologically contain or eradicate the organism without pathology developing. However, in a minority, the organism overcomes the immunological constraints, proliferates and causes TB disease. Each year a million children develop TB disease, with a quarter dying. While it is known that young children and those with immunodeficiencies are at increased risk of progression from TB infection to TB disease, our understanding of risk factors for this transition is limited. The most immunologically disruptive process that can happen during childhood is infection with another pathogen and yet the impact of co-infections on TB risk is poorly investigated. Many diseases have overlapping geographical distributions to TB and affect similar patient populations. It is therefore likely that infection with viruses, bacteria, fungi and protozoa may impact on the risk of developing TB disease following exposure and infection, although disentangling correlation and causation is challenging. As vaccinations also disrupt immunological pathways, these may also impact on TB risk. In this article we describe the pediatric immune response to M. tuberculosis and then review the existing evidence of the impact of co-infection with other pathogens, as well as vaccination, on the host response to M. tuberculosis. We focus on the impact of other organisms on the risk of TB disease in children, in particularly evaluating if co-infections drive host immune responses in an age-dependent way. We finally propose priorities for future research in this field. An improved understanding of the impact of co-infections on TB could assist in TB control strategies, vaccine development (for TB vaccines or vaccines for other organisms), TB treatment approaches and TB diagnostics.

The burden of multidrug-resistant tuberculosis in children

BACKGROUND

Childhood tuberculosis (TB) has historically been neglected, although in recent years there has been increased focus on this problem. In particular, there have been two efforts to estimate the burden of pediatric multidrug-resistant TB (MDR-TB).

METHODS

We review current estimates of the global incidence of pediatric MDR-TB disease. We then combine pediatric MDR-TB treatment data from the World Health Organization and recently published case fatality ratio estimates for children with TB to produce mortality estimates for children with MDR-TB. Finally, we combine treatment data and estimates of household size and disease risk to estimate how many children could be treated for probable or confirmed MDR-TB by carrying out household contact investigations around adult MDR-TB patients.

RESULTS

Between 25 000 and 32 000 children develop MDR-TB disease annually, accounting for around 3% of all pediatric TB cases. Only 3-4% of these children are likely to receive MDR-TB treatment. We estimate that around 21% of children who develop MDR-TB disease will die. Carrying out household contact investigations around adult MDR-TB patients could find an estimated 12 times as many pediatric MDR-TB cases as are currently being identified.

DISCUSSION

The diagnosis and treatment of children with MDR-TB needs to be prioritized by TB programs.

Diagnostic role of medical thoracoscopy in childhood pleural tuberculosis

Currently, the diagnostic role of medical thoracoscopy in childhood pleural tuberculosis remains uncertain. Therefore, this retrospective study was conducted to evaluate the diagnostic performance of histological examination of tissue samples obtained by medical thoracoscopy in childhood pleural tuberculosis. Hospitalized children who underwent medical thoracoscopy between May 2012 and March 2016 were included in the study. Tissue samples obtained by thoracoscopy were submitted for histological examination (hematoxylin and eosin staining). Descriptive statistical methods were used for data interpretation, and the data were expressed as the mean ± standard deviation. The childhood tuberculosis patients had the following characteristics: 11 had pleural tuberculosis and 9 had pleural tuberculosis + pulmonary tuberculosis, the average age was 13.0 ± 2.2 years old, 60% were male, 26.3% (5/19) of patients tested positive for acid-fast bacilli positive in smears, 21.1% (4/19) of patients were positive for TB-PCR, and 90% (18) of pleural tuberculosis patients were positive in the culture for Mycobacterium tuberculosis. The sensitivity of histological examinations of tissue samples obtained by thoracoscopy in the detection of pleural tuberculosis was 80% (16/20). Complications were reported in 15 cases, and all complications disappeared spontaneously without any specific treatment. Therefore, we concluded that medical thoracoscopy was a sensitive and safe tool for the detection of childhood pleural tuberculosis.

Prevention of tuberculosis in household members: estimates of children eligible for treatment

Objective

To estimate of the number of children younger than 5 years who were household contacts of people with tuberculosis and were eligible for tuberculosis preventive treatment in 2017.

Methods

To estimate the number of eligible children, we obtained national values for the number of notified cases of bacteriologically confirmed pulmonary tuberculosis in 2017, the proportion of the population younger than 5 years in 2017 and average household size from published sources. We obtained global values for the number of active tuberculosis cases per household with an index case and for the prevalence of latent tuberculosis infection among children younger than 5 years who were household contacts of a tuberculosis case through systematic reviews, meta-analysis and Poisson regression models.

Findings

The estimated number of children younger than 5 years eligible for tuberculosis preventive treatment in 2017 globally was 1.27 million (95% uncertainty interval, UI: 1.24–1.31), which corresponded to an estimated global coverage of preventive treatment in children of 23% at best. By country, the estimated number ranged from less than one in the Bahamas, Iceland, Luxembourg and Malta to 350 000 (95% UI: 320 000–380 000) in India. Regionally, the highest estimates were for the World Health Organization (WHO) South-East Asia Region (510 000; 95% UI: 450 000–580 000) and the WHO African Region (470 000; 95% UI: 440 000–490 000).

Conclusion

Tuberculosis preventive treatment in children was underutilized globally in 2017. Treatment should be scaled up to help eliminate the pool of tuberculosis infection and achieve the End TB Strategy targets.

Epidemiological characteristics of pulmonary tuberculosis among children in Shandong, China, 2005-2017

BACKGROUND

Diagnosis of tuberculosis (TB) in children is challenging. Epidemiological data of childhood pulmonary tuberculosis (PTB) are urgently needed.

METHODS

We described trends in epidemiology, clinical characteristics, and treatment outcomes in seven cities of Shandong province, China, during 2005-2017. Data were collected from the China Information System for Disease Control and Prevention.

RESULTS

Among 6283 (2.4% of all PTB) PTB cases aged < 18 years, 56.5% were male patients, 39.3% were smear-positive and 98.6% were new cases. The overall incidence of childhood PTB declined (7.62 to 3.74 per 100,000) during 2005-2017, with a non-significant change of annual percentage after 2010. While the incidence of smear-positive PTB (6.09 to 0.38 per 100,000 population) decreased significantly, but the incidence of smear-negative PTB (1.52 to 3.36 per 100,000 population) increased significantly during 2005-2017. The overall treatment success occurred among 94.2% childhood PTB. Ten children (0.2%) died.

CONCLUSION

The overall incidence of childhood PTB declined significantly with the disease burden shifting from smear-positive PTB to smear-negative PTB. The discrepancies between notifications and estimations in both TB morbidity and mortality of children need to be addressed urgently.

Paediatric tuberculosis transmission outside the household: challenging historical paradigms to inform future public health strategies

Tuberculosis is a major cause of death and disability among children globally, yet children have been neglected in global tuberculosis control efforts. Historically, tuberculosis in children has been thought of as a family disease, and because of this, household contact tracing of children after identification of an adult tuberculosis case has been emphasised as the principal public health intervention. However, the population-level effect of household contact tracing is predicated on the assumption that most paediatric tuberculosis infections are acquired within the household. In this Personal View, we focus on accumulating scientific evidence indicating that the majority of Mycobacterium tuberculosis transmission to children in high-burden settings occurs in the community, outside of households in which a person has tuberculosis. We estimate the population-attributable fraction of M tuberculosis transmission to children due to household exposures to be between 10% and 30%. M tuberculosis transmission from the household was low (<30%) even in children younger than age 5 years. We propose that an effective public health response to childhood tuberculosis requires comprehensive, community-based interventions, such as active surveillance in select settings, rather than contact tracing alone. Importantly, the historical paradigm that most paediatric transmission occurs in households should be reconsidered on the basis of the scientific knowledge presented.

The Changing Landscape of Childhood Tuberculosis in the United Kingdom: A Retrospective Cohort (2000-2015)

BACKGROUND

The epidemiology of tuberculosis (TB) is changing in the United Kingdom and globally. Childhood TB is a key indicator of recent transmission and provides a marker of wider TB control. We describe the recent epidemiology of childhood TB in the United Kingdom, how this compares to TB in adults, and document changes with time.

METHODS

TB cases notified in the United Kingdom between 2000 and 2015 were categorized as children (<15 years of age) or adults (≥15 years of age). Descriptive analyses were carried out on demographic, clinical and microbiologic data. We carried out logistic regressions to identify risk factors associated with children having no microbiologic confirmation.

RESULTS

In the study period, 6293 TB cases (5%) in the United Kingdom were notified in children. Childhood TB incidence declined from 487 cases in 2000 (3.4 per 100,000) to 232 cases (2.0 per 100,000) in 2015. The majority (68%) of children with TB were UK born, with a high proportion of Pakistani (24%) and Black-African (22%) ethnicity. Sixty-four percent of children had pulmonary disease. Culture confirmation was low (24%). Children who were younger, UK born and those with extrapulmonary disease were less likely to have microbiologically confirmed TB. A high proportion (87%) of children completed treatment at last-recorded outcome, with few deaths (39 cases; 0.7%).

CONCLUSIONS

The incidence of TB in children in the United Kingdom has decreased in the past 16 years, with the majority of children completing TB treatment. Ongoing monitoring of childhood TB will provide a measure of the effectiveness of the national TB program.

Sub-national TB prevalence surveys in India, 2006-2012: Results of uniformly conducted data analysis

Setting

Community based tuberculosis (TB) prevalence surveys in ten sites across India during 2006–2012

Objective

To re-analyze data of recent sub-national surveys using uniform statistical methods and obtain a pooled national level estimate of prevalence of TB.

Methods

Individuals ≥15 years old were screened by interview for symptoms suggestive of Pulmonary TB (PTB) and history of anti-TB treatment; additional screening by chest radiography was undertaken in five sites. Two sputum specimens were examined by smear and culture among Screen-positives. Prevalence in each site was estimated after imputing missing values to correct for bias introduced by incompleteness of data. In five sites, prevalence was corrected for non-screening by radiography. Pooled prevalence of bacteriologically positive PTB was estimated using Random Effects Model after excluding data from one site. Overall prevalence of TB (all ages, all types) was estimated by adjusting for extra-pulmonary TB and Pediatric TB.

Results

Of 769290 individuals registered, 715989 were screened by interview and 294532 also by radiography. Sputum specimen were examined from 50 852 individuals. Estimated prevalence of smear positive, culture positive and bacteriologically positive PTB varied between 108.4–428.1, 147.9–429.8 and 170.8–528.4 per 100000 populations in different sites. Pooled estimate of prevalence of bacteriologically positive PTB was 350.0 (260.7, 439.0). Overall prevalence of TB was estimated at 300.7 (223.7–377.5) in 2009, the mid-year of surveys. Prevalence was significantly higher in rural compared to urban areas.

Conclusion

TB burden continues to be high in India suggesting further strengthening of TB control activities.

Under-reporting of diagnosed tuberculosis to the national surveillance system in China: an inventory study in nine counties in 2015

OBJECTIVE

The WHO estimates that almost 40% of patients diagnosed with tuberculosis (TB) are not reported. We implemented this study to assess TB under-reporting and delayed treatment registration in nine counties in China.

DESIGN

A retrospective inventory study (record review).

SETTING

Counties were selected using purposive sampling from nine provinces distributed across eastern, central and western regions of China in 2015.

PRIMARY AND SECONDARY OUTCOME MEASURES

Under-reporting was calculated as the percentage of patients with TB not reported to TB Information Management System (TBIMS) within 6 months of diagnosis. Delayed registration was estimated as the percentage of reported cases initiating treatment 7 or more days after diagnosis. Multivariable logistic regression and an alpha level of 0.05 were used to examine factors associated with these outcomes.

RESULTS

Of the 5606 patients with TB identified from project health facilities and social insurance systems, 1082 (19.3%) were not reported to TBIMS. Of the 4524 patients successfully reported, 1416 (31.3%) were not registered for treatment within 7 days of diagnosis. Children, TB pleurisy, patients diagnosed in the eastern and central regions and patients with a TB diagnosis recorded in either health facilities or social insurance system-but not both-were statistically more likely to be unreported. Delayed treatment registration was more likely for previously treated patients with TB, patients with negative or unknown sputum results and for patients diagnosed in the eastern region.

CONCLUSION

Almost one in every five patients diagnosed with TB in this study was unknown to local or national TB control programmes. We recommend strengthening TB data management practices, particularly in the eastern and central regions, and developing specific guidelines for reporting paediatric TB and TB pleurisy. Patient education and follow-up by diagnosing facilities could improve timely treatment registration. Additional studies are needed to assess under-reporting elsewhere in China.

Epidemiological aspects, clinical manifestations, and prevention of pediatric tuberculosis from the perspective of the End TB Strategy

Tuberculosis continues to be a public health priority in many countries. In 2015, tuberculosis killed 1.4 million people, including 210,000 children. Despite the recent progress made in the control of tuberculosis in Brazil, it is still one of the countries with the highest tuberculosis burdens. In 2015, there were 69,000 reported cases of tuberculosis in Brazil and tuberculosis was the cause of 4,500 deaths in the country. In 2014, the World Health Organization approved the End TB Strategy, which set a target date of 2035 for meeting its goals of reducing the tuberculosis incidence by 90% and reducing the number of tuberculosis deaths by 95%. However, to achieve those goals in Brazil, there is a need for collaboration among the various sectors involved in tuberculosis control and for the prioritization of activities, including control measures targeting the most vulnerable populations. Children are highly vulnerable to tuberculosis, and there are particularities specific to pediatric patients regarding tuberculosis development (rapid progression from infection to active disease), prevention (low effectiveness of vaccination against the pulmonary forms and limited availability of preventive treatment of latent tuberculosis infection), diagnosis (a low rate of bacteriologically confirmed diagnosis), and treatment (poor availability of child-friendly anti-tuberculosis drugs). In this review, we discuss the epidemiology, clinical manifestations, and prevention of tuberculosis in childhood and adolescence, highlighting the peculiarities of active and latent tuberculosis in those age groups, in order to prompt reflection on new approaches to the management of pediatric tuberculosis within the framework of the End TB Strategy.

Tuberculosis in Children

Mycobacterium tuberculosis is the leading cause of death worldwide from a single bacterial pathogen. The World Health Organization estimates that annually 1 million children have tuberculosis (TB) disease and many more harbor a latent form. Accurate estimates are hindered by under-recognition and challenges in diagnosis. To date, an accurate diagnostic test to confirm TB in children does not exist. Treatment is lengthy but outcomes are generally favorable with timely initiation. With the End TB Strategy, there is an urgent need for improved diagnostics and treatment to prevent the unnecessary morbidity and mortality from TB in children.

Estimating the prevalence of latent tuberculosis in a low-incidence setting: Australia

Migration is a key driver of tuberculosis (TB) in many low-incidence settings, with the majority of TB cases attributed to reactivation of latent TB (LTBI) acquired overseas. A greater understanding of LTBI risk in heterogeneous migrant populations would aid health planning. We aimed to estimate the LTBI prevalence and distribution among locally born and overseas-born Australians.

Annual risks of TB infection estimates were applied to population cohorts (by country of birth, year of arrival and age) in Australian census data in 2006, 2011 and 2016.

Both the absolute number and proportion of Australian residents with LTBI increased from 4.6% (interquartile range (IQR) 4.2–5.2%) in 2006 to 5.1% (IQR 4.7–5.5%) in 2016, due to the increasing proportion of the population born overseas (23.8% in 2006 to 28.3% in 2016). Of all residents estimated to have LTBI in 2016; 93.2% were overseas born, 21.6% were aged <35 years and 34.4% had migrated to Australia since 2007.

The overall prevalence of LTBI in Australia is low. Some residents, particularly migrants from high-incidence settings, may have considerably higher risk of LTBI, and these findings allow for tailored public health interventions to reduce the risk and impact of future TB disease.

Global, regional, and national burden of tuberculosis, 1990-2016: results from the Global Burden of Diseases, Injuries, and Risk Factors 2016 Study

BACKGROUND

Although a preventable and treatable disease, tuberculosis causes more than a million deaths each year. As countries work towards achieving the Sustainable Development Goal (SDG) target to end the tuberculosis epidemic by 2030, robust assessments of the levels and trends of the burden of tuberculosis are crucial to inform policy and programme decision making. We assessed the levels and trends in the fatal and non-fatal burden of tuberculosis by drug resistance and HIV status for 195 countries and territories from 1990 to 2016.

METHODS

We analysed 15 943 site-years of vital registration data, 1710 site-years of verbal autopsy data, 764 site-years of sample-based vital registration data, and 361 site-years of mortality surveillance data to estimate mortality due to tuberculosis using the Cause of Death Ensemble model. We analysed all available data sources, including annual case notifications, prevalence surveys, population-based tuberculin surveys, and estimated tuberculosis cause-specific mortality to generate internally consistent estimates of incidence, prevalence, and mortality using DisMod-MR 2.1, a Bayesian meta-regression tool. We assessed how the burden of tuberculosis differed from the burden predicted by the Socio-demographic Index (SDI), a composite indicator of income per capita, average years of schooling, and total fertility rate.

FINDINGS

Globally in 2016, among HIV-negative individuals, the number of incident cases of tuberculosis was 9·02 million (95% uncertainty interval [UI] 8·05-10·16) and the number of tuberculosis deaths was 1·21 million (1·16-1·27). Among HIV-positive individuals, the number of incident cases was 1·40 million (1·01-1·89) and the number of tuberculosis deaths was 0·24 million (0·16-0·31). Globally, among HIV-negative individuals the age-standardised incidence of tuberculosis decreased annually at a slower rate (-1·3% [-1·5 to -1·2]) than mortality did (-4·5% [-5·0 to -4·1]) from 2006 to 2016. Among HIV-positive individuals during the same period, the rate of change in annualised age-standardised incidence was -4·0% (-4·5 to -3·7) and mortality was -8·9% (-9·5 to -8·4). Several regions had higher rates of age-standardised incidence and mortality than expected on the basis of their SDI levels in 2016. For drug-susceptible tuberculosis, the highest observed-to-expected ratios were in southern sub-Saharan Africa (13·7 for incidence and 14·9 for mortality), and the lowest ratios were in high-income North America (0·4 for incidence) and Oceania (0·3 for mortality). For multidrug-resistant tuberculosis, eastern Europe had the highest observed-to-expected ratios (67·3 for incidence and 73·0 for mortality), and high-income North America had the lowest ratios (0·4 for incidence and 0·5 for mortality).

INTERPRETATION

If current trends in tuberculosis incidence continue, few countries are likely to meet the SDG target to end the tuberculosis epidemic by 2030. Progress needs to be accelerated by improving the quality of and access to tuberculosis diagnosis and care, by developing new tools, scaling up interventions to prevent risk factors for tuberculosis, and integrating control programmes for tuberculosis and HIV.

FUNDING

Bill & Melinda Gates Foundation.

Incidence of tuberculosis and the influence of surveillance strategy on tuberculosis case-finding and all-cause mortality: a cluster randomised trial in Indian neonates vaccinated with BCG

Introduction

Accurate tuberculosis (TB) incidence and optimal surveillance strategies are pertinent to TB vaccine trial design. Infants are a targeted population for new TB vaccines, but data from India, with the highest global burden of TB cases, is limited.

Methods

In a population-based prospective trial conducted between November 2006 and July 2008, BCG-vaccinated neonates in South India were enrolled and cluster-randomised to active or passive surveillance. We assessed the influence of surveillance strategy on TB incidence, case-finding rates and all-cause mortality. Predefined criteria were used to diagnose TB. All deaths were evaluated using a verbal autopsy.

Results

4382 children contributed to 8164 person-years (py) of follow-up (loss to follow-up 6.9%); 749 children were admitted for TB evaluation (active surveillance: 641; passive surveillance: 108). The TB incidence was 159.2/100 000 py and the overall case-finding rate was 3.19 per 100 py (95% CI 0.82 to 18.1). Whereas, the case-finding rate for definite TB was similar using active or passive case finding, the case-finding rate for probable TB was 1.92/100 py (95% CI 0.83 to 3.78) with active surveillance, significantly higher than 0.3/100 py (95% CI 0.01 to 1.39, p=0.02) with passive surveillance. Compared to passive surveillance, children with active surveillance had decreased risk of dying (OR 0.68, 95%CI 0.47 to 0.98) which was mostly attributable to reduction of death from pneumonia/respiratory infections (OR 0.34, 95%CI 0.14 to 0.80).

Conclusion

We provide reliable estimates of TB incidence in South Indian children <2 years of age. Active surveillance increased the case-finding rates for probable TB and was associated with reduced all-cause mortality.

Epidemiology of Pediatric Tuberculosis in Kenya and Risk Factors for Mortality during Treatment: A National Retrospective Cohort Study

OBJECTIVES

To describe the epidemiology of childhood tuberculosis (TB) in Kenya, assess the magnitude of TB/human immunodeficiency virus (HIV) co-infection and identify risk factors for mortality during TB treatment.

STUDY DESIGN

We conducted a retrospective analysis of the Kenyan national TB program data for patients enrolled from 2013 through 2015. A total of 23 753 children aged less than 15 years were included in the analysis. Survival analysis was performed with censorship at 9 months and mortality was the main outcome. We used Cox proportional hazards regression for assessing risk factors for mortality.

RESULTS

Childhood TB accounted for 9% (n = 24 216) of all patients with TB; 98% of the notified children (n = 23 753) were included in the analysis. TB/HIV co-infection was 28% (n = 6112). Most TB cases (71%; n = 16 969) were detected through self-referral. Treatment was successful in 90% (n = 19 088) and 4% (n = 1058) died. Independent risk factors for mortality included being HIV infected but not on antiretroviral therapy (adjusted hazard ratio [aHR], 4.84; 95% CI, 3.59-6.51), being HIV infected and on antiretroviral therapy (aHR, 3.69; 95% CI, 3.14-4.35), children aged less than 5 years (aHR, 1.25; 95% CI, 1.08-1.44), and being diagnosed with smear negative pulmonary disease (aHR, 1.68; 95% CI, 1.27-2.24).

CONCLUSIONS

Most childhood TB cases in Kenya were detected through passive case finding. TB/HIV co-infection is high among children on treatment for TB, and HIV is associated with an increased risk of death. There is a need to intensify active case finding among children. TB prevention interventions among HIV-infected children, early diagnosis of HIV, and early antiretroviral therapy initiation among children on TB treatment should be strengthened.

Predictive Indicators to Identify High-Risk Paediatric Febrile Neutropenia in Paediatric Oncology Patients in a Middle-Income Country

PURPOSE

To validate a clinical risk prediction score (Ammann score) to predict adverse events (AEs) in paediatric febrile neutropenia (FN).

PATIENTS AND METHODS

Patients <16 years of age were enrolled. A risk prediction score (based on haemoglobin ≥ 9 g/dl, white cell count (WCC) < 0.3 G/l, platelet count <50 G/l and chemotherapy more intensive than acute lymphoblastic leukaemia maintenance therapy) was calculated and AEs were documented.

RESULTS

In total, 100 FN episodes occurred in 52 patients, male:female ratio was 1.8:1 and median age was 56 months. At reassessment, AEs occurred in 18 of 55 (45%) low-risk FN episodes (score < 9) and 21 of 42 (55%) high-risk episodes (score ≥9) (sensitivity 60%, specificity 65%, positive predictive value 53%, negative predictive value 71%). Total WCC and absolute monocyte count (AMC) were significantly associated with AEs.

CONCLUSION

This study identified total WCC and AMC as significantly associated with AEs but failed to validate the risk prediction score.

Potential effect of household contact management on childhood tuberculosis: a mathematical modelling study

BACKGROUND

Tuberculosis is recognised as a major cause of morbidity and mortality in children, with most cases in children going undiagnosed and resulting in poor outcomes. Household contact management, which aims to identify children with active tuberculosis and to provide preventive therapy for those with HIV or those younger than 5 years, has long been recommended but has very poor coverage globally. New guidelines include widespread provision of preventive therapy to children with a positive tuberculin skin test (TST) who are older than 5 years.

METHODS

In this mathematical modelling study, we provide the first global and national estimates of the impact of moving from zero to full coverage of household contact management (with and without preventive therapy for TST-positive children older than 5 years). We assembled data on tuberculosis notifications, household structure, household contact co-prevalence of tuberculosis disease and infection, the efficacy of preventive therapy, and the natural history of childhood tuberculosis. We used a model to estimate households visited, children screened, and treatment courses given for active and latent tuberculosis. We calculated the numbers of tuberculosis cases, deaths, and life-years lost because of tuberculosis for each intervention scenario and country.

FINDINGS

We estimated that full implementation of household contact management would prevent 159 500 (75% uncertainty interval [UI] 147 000-170 900) cases of tuberculosis and 108 400 (75% UI 98 800-116 700) deaths in children younger than 15 years (representing the loss of 7 305 000 [75% UI 6 663 000-7 874 000] life-years). We estimated that preventing one child death from tuberculosis would require visiting 48 households, screening 77 children, giving 48 preventive therapy courses, and giving two tuberculosis treatments versus no household contact management.

INTERPRETATION

Household contact management could substantially reduce childhood disease and death caused by tuberculosis globally. Funding and research to optimise its implementation should be prioritised.

FUNDING

UK Medical Research Council, US National Institutes of Health, Fulbright Commission, Janssen Global Public Health.

Biomarkers for diagnosis of childhood tuberculosis: A systematic review

Introduction

As studies of biomarkers of tuberculosis (TB) disease provide hope for a simple, point-of-care test, we aimed to synthesize evidence on biomarkers for diagnosis of TB in children and compare their accuracy to published target product profiles (TPP).

Methods

We conducted a systematic review of biomarkers for diagnosis of pulmonary TB in exclusively paediatric populations, defined as age less than 15 years. PubMed, EMBASE and Web of Science were searched for relevant publications from January 1, 2000 to November 27, 2017. Studies using mixed adult and paediatric populations or reporting biomarkers for extrapulmonary TB were excluded. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies—2 (QUADAS-2) framework. No meta-analysis was done because the published childhood TB biomarkers studies were mostly early stage studies and highly heterogeneous.

Results

The 29 studies included in this systematic review comprise 20 case-control studies, six cohort studies and three cross-sectional studies. These studies reported diverse and heterogeneous forms of biomarkers requiring different types of clinical specimen and laboratory assays. Majority of the studies (27/29 [93%]) either did not meet the criteria in at least one of the four domains of the QUADAS-2 reporting framework or the assessment was unclear. However, the diagnostic performance of biomarkers reported in 22 studies met one or both of the WHO-recommended minimal targets of 66% sensitivity and 98% specificity for a new diagnostic test for TB disease in children, and/or 90% sensitivity and 70% specificity for a triage test.

Conclusion

We found that majority of the biomarkers for diagnosis of TB in children are promising but will need further refining and optimization to improve their performances. As new data are emerging, stronger emphasis should be placed on improving the design, quality and general reporting of future studies investigating TB biomarkers in children.

The association of household fine particulate matter and kerosene with tuberculosis in women and children in Pune, India

OBJECTIVES

Household air pollution (HAP) is a risk factor for respiratory disease, however has yet to be definitively associated with tuberculosis (TB). We aimed to assess the association between HAP and TB.

METHODS

A matched case-control study was conducted among adult women and children patients with TB and healthy controls matched on geography, age and sex. HAP was assessed using questionnaires for pollution sources and 24-hour household concentrations of particulate matter <2.5 μm in diameter (PM_2.5).

RESULTS

In total, 192 individuals in 96 matched pairs were included. The median 24-hour time-weighted average PM_2.5 was nearly seven times higher than the WHO's recommendation of 25 µg/m³, and did not vary between controls (179 µg/m³; IQR: 113-292) and cases (median 157 µg/m³; 95% CI 93 to 279; p=0.57). Reported use of wood fuel was not associated with TB (OR 2.32; 95% CI 0.65 to 24.20) and kerosene was significantly associated with TB (OR 5.49, 95% CI 1.24 to 24.20) in adjusted analysis. Household PM_2.5 was not associated with TB in univariate or adjusted analysis. Controlling for PM_2.5 concentration, kerosene was not significantly associated with TB, but effect sizes ranged from OR 4.30 (95% CI 0.78 to 30.86; p=0.09) to OR 5.49 (0.82 to 36.75; p=0.08).

CONCLUSIONS

Use of kerosene cooking fuel is positively associated with TB in analysis using reported sources of exposure. Ubiquitously high levels of particulates limited detection of a difference in household PM_2.5 between cases and controls.

Treatment of tuberculosis infection in children

INTRODUCTION

Identifying and treating children with tuberculosis (TB) infection in both low and high-TB burden settings will decrease the incidence of TB disease worldwide. Areas covered: This review covers each of the available TB infection treatment options for children based on effectiveness, safety, tolerability and treatment completion rates. Six to 9 months of daily administered isoniazid is no longer the treatment of choice for many children with TB infection. Shorter, rifamycin based, TB infection treatment regimens are effective, safe and easier for children to complete. Fluroquinolone-based regimens are recommended for the treatment of children infected by a source case with drug-resistant TB. Directly observed therapy (DOT) programs improve childhood TB infection treatment completion rates. Expert commentary: As shorter, rifamycin-based, TB infection treatment regimens offer superior treatment success rate in both adults and children; the widespread use of these regimens has huge potential to decrease the burden of TB disease worldwide. The implementation of these programs will involve improving patient access to the medications, decreasing their cost to the patient, and the use of novel electronic methods to document patient treatment completion.

Isoniazid for the Prevention of Tuberculosis in HIV-Infected Children: A Systematic Review and Meta-Analysis

BACKGROUND

Isoniazid is recommended for prevention of tuberculosis (TB) in HIV-infected adults, but its efficacy in children living with HIV (CLHIV) is not known. We performed a systematic review to assess the efficacy of isoniazid for the prevention of TB in CLHIV.

METHODS

We searched PubMed, Cochrane Clinical Trial Registry and Google Scholar from inception to December 2016. Any randomized controlled trial assessing the role of isoniazid for the prevention of TB in CLHIV was eligible for inclusion. The primary endpoint was TB incidence; secondary end points were mortality, overall survival and severe adverse events. Dual independent extraction of all data was performed. Data were pooled under a random effects model and summarized either as risk ratio (RR) or hazard ratio along with 95% confidence intervals (CIs).

RESULTS

Of 931 references, 3 randomized controlled trials enrolling 977 patients met the inclusion criteria. Pooled results showed a statistically nonsignificant reduction in TB incidence (RR: 0.70; 95% CI: 0.47-1.04; P = 0.07) and mortality (RR: 0.94; 95% CI: 0.39-2.23; P = 0.88) with the use of isoniazid compared with placebo. One study was stopped early because of excess deaths in the placebo arm. However, results from subgroup analysis restricted to only completed trials did not change the overall findings.

CONCLUSIONS

Isoniazid did not reduce the incidence of TB in CLHIV. All included studies were performed in regions with high prevalence of TB making the overall generalizability limited.

Variability in distribution and use of tuberculosis diagnostic tests in Kenya: a cross-sectional survey

Background

Globally, 40% of all tuberculosis (TB) cases, 65% paediatric cases and 75% multi-drug resistant TB (MDR-TB) cases are missed due to underreporting and/or under diagnosis. A recent Kenyan TB prevalence survey found that a significant number of TB cases are being missed here. Understanding spatial distribution and patterns of use of TB diagnostic tests as per the guidelines could potentially help improve TB case detection by identifying diagnostic gaps.

Methods

We used 2015 Kenya National TB programme data to map TB case notification rates (CNR) in different counties, linked with their capacity to perform diagnostic tests (chest x-rays, smear microscopy, Xpert MTB/RIF®, culture and line probe assay). We then ran hierarchical regression models for adults and children to specifically establish determinants of use of Xpert® (as per Kenyan guidelines) with county and facility as random effects.

Results

In 2015, 82,313 TB cases were notified and 7.8% were children. The median CNR/100,000 amongst 0-14yr olds was 37.2 (IQR 20.6, 41.0) and 267.4 (IQR 202.6, 338.1) for ≥15yr olds respectively. 4.8% of child TB cases and 12.2% of adult TB cases had an Xpert® test done, with gaps in guideline adherence. There were 2,072 microscopy sites (mean microscopy density 4.46/100,000); 129 Xpert® sites (mean 0.31/100,000); two TB culture laboratories and 304 chest X-ray facilities (mean 0.74/100,000) with variability in spatial distribution across the 47 counties. Retreatment cases (i.e. failures, relapses/recurrences, defaulters) had the highest odds of getting an Xpert® test compared to new/transfer-in patients (AOR 7.81, 95% CI 7.33-8.33). Children had reduced odds of getting an Xpert® (AOR 0.41, CI 0.36-0.47). HIV-positive individuals had nearly twice the odds of getting an Xpert® test (AOR 1.82, CI 1.73-1.92). Private sector and higher-level hospitals had a tendency towards lower odds of use of Xpert®.

Conclusions

We noted under-use and gaps in guideline adherence for Xpert® especially in children. The under-use despite considerable investment undermines cost-effectiveness of Xpert®. Further research is needed to develop strategies enhancing use of diagnostics, including innovations to improve access (e.g. specimen referral) and overcoming local barriers to adoption of guidelines and technologies.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3237-z) contains supplementary material, which is available to authorized users.

Epidemiology of tuberculosis in Papua New Guinea: analysis of case notification and treatment-outcome data, 2008-2016

Papua New Guinea has strengthened its surveillance system for tuberculosis (TB) under the National TB Program. This paper provides an overview of TB surveillance data at the national and subnational levels from 2008 to 2016. TB case notification has consistently increased since 2008 with 6184 cases (93 per 100 000 population) in 2008 to 28 598 (359 per 100 000 population) in 2014 and has stabilized since 2014 with 28 244 cases (333 per 100 000 population) in 2016. The population-screening rate for TB rose from 0.1% in 2008 to 0.4% in 2016. Notified cases were dominated by extra-pulmonary TB (EP-TB, 42.4% of all cases in 2016). The proportion of pulmonary TB cases with no sputum test results was high with a national average of 26.6%. The regional variation of case notifications was significant: the Southern Region had the highest number and rate of notified TB cases. Of the nationally reported cases, 26.7% occurred in children. Treatment success rates remained low at 73% for bacteriologically confirmed TB and 64% for all forms of TB in 2016, far below the global target of 90%. For all forms of TB, 19% of patients were lost to follow-up from treatment. An analysis of TB data from the national surveillance system has highlighted critical areas for improvement. A low population-screening rate, a high proportion of pulmonary TB cases without sputum test results and a low treatment success rate suggest areas for improvement in the National TB Program. Our additional subnational analysis helps identify geographical and programmatic areas that need strengthening and should be further promoted to guide the programme's direction in Papua New Guinea.

Times series analysis of age-specific tuberculosis at a rapid developing region in China, 2011-2016

The city of Shenzhen has recently experienced extraordinary economic growth accompanied by a huge internal migrant influx. We investigated the local dynamics of tuberculosis (TB) epidemiology in the Nanshan District of Shenzhen to provide insights for TB control strategies for this district and other rapidly developing regions in China. We analyzed the age-specific incidence and number of TB cases in the Nanshan District from 2011 to 2016. Over all, the age-standardized incidence of TB decreased at an annual rate of 3.4%. The incidence was lowest amongst the age group 0-14 and showed no increase in this group over the six-year period (P = 0.587). The fastest decreasing incidence was among the 15-24 age group, with a yearly decrease of 13.3% (β = 0.867, P < 0.001). In contrast, the TB incidence increased in the age groups 45-54, 55-54, and especially in those aged ≥65, whose yearly increase was 13.1% (β = 1.131, P < 0.001). The peak time of TB case presentation was in April, May, and June for all age groups, except in August for the 45-54 cohort. In the rapidly developing Nanshan District, TB control policies targeted to those aged 45 years and older should be considered. The presentation of TB cases appears to peak in the spring months.

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

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