Paediatrics (RCH) - Research Publications
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ItemInfant BCG vaccination and risk of pulmonary and extrapulmonary tuberculosis throughout the life course: a systematic review and individual participant data meta-analysis.(Elsevier BV, 2022-09)BACKGROUND: BCG vaccines are given to more than 100 million children every year, but there is considerable debate regarding the effectiveness of BCG vaccination in preventing tuberculosis and death, particularly among older children and adults. We therefore aimed to investigate the age-specific impact of infant BCG vaccination on tuberculosis (pulmonary and extrapulmonary) development and mortality. METHODS: In this systematic review and individual participant data meta-analysis, we searched MEDLINE, Web of Science, BIOSIS, and Embase without language restrictions for case-contact cohort studies of tuberculosis contacts published between Jan 1, 1998, and April 7, 2018. Search terms included "mycobacterium tuberculosis", "TB", "tuberculosis", and "contact". We excluded cohort studies that did not provide information on BCG vaccination or were done in countries that did not recommend BCG vaccination at birth. Individual-level participant data for a prespecified list of variables, including the characteristics of the exposed participant (contact), the index case, and the environment, were requested from authors of all eligible studies. Our primary outcome was a composite of prevalent (diagnosed at or within 90 days of baseline) and incident (diagnosed more than 90 days after baseline) tuberculosis in contacts exposed to tuberculosis. Secondary outcomes were pulmonary tuberculosis, extrapulmonary tuberculosis, and mortality. We derived adjusted odds ratios (aORs) using mixed-effects, binary, multivariable logistic regression analyses with study-level random effects, adjusting for the variable of interest, baseline age, sex, previous tuberculosis, and whether data were collected prospectively or retrospectively. We stratified our results by contact age and Mycobacterium tuberculosis infection status. This study is registered with PROSPERO, CRD42020180512. FINDINGS: We identified 14 927 original records from our database searches. We included participant-level data from 26 cohort studies done in 17 countries in our meta-analysis. Among 68 552 participants, 1782 (2·6%) developed tuberculosis (1309 [2·6%] of 49 686 BCG-vaccinated participants vs 473 [2·5%] of 18 866 unvaccinated participants). The overall effectiveness of BCG vaccination against all tuberculosis was 18% (aOR 0·82, 95% CI 0·74-0·91). When stratified by age, BCG vaccination only significantly protected against all tuberculosis in children younger than 5 years (aOR 0·63, 95% CI 0·49-0·81). Among contacts with a positive tuberculin skin test or IFNγ release assay, BCG vaccination significantly protected against tuberculosis among all participants (aOR 0·81, 95% CI 0·69-0·96), participants younger than 5 years (0·68, 0·47-0·97), and participants aged 5-9 years (0·62, 0·38-0·99). There was no protective effect among those with negative tests, unless they were younger than 5 years (0·54, 0·32-0·90). 14 cohorts reported on whether tuberculosis was pulmonary or extrapulmonary (n=57 421). BCG vaccination significantly protected against pulmonary tuberculosis among all participants (916 [2·2%] in 41 119 vaccinated participants vs 334 [2·1%] in 16 161 unvaccinated participants; aOR 0·81, 0·70-0·94) but not against extrapulmonary tuberculosis (106 [0·3%] in 40 318 vaccinated participants vs 38 [0·2%] in 15 865 unvaccinated participants; 0·96, 0·65-1·41). In the four studies with mortality data, BCG vaccination was significantly protective against death (0·25, 0·13-0·49). INTERPRETATION: Our results suggest that BCG vaccination at birth is effective at preventing tuberculosis in young children but is ineffective in adolescents and adults. Immunoprotection therefore needs to be boosted in older populations. FUNDING: National Institutes of Health.
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ItemAetiology of childhood pneumonia in low- and middle-income countries in the era of vaccination: a systematic review.(International Global Health Society, 2022-07-23)Background: This systematic review aimed to describe common aetiologies of severe and non-severe community acquired pneumonia among children aged 1 month to 9 years in low- and middle-income countries. Methods: We searched the MEDLINE, EMBASE, and PubMed online databases for studies published from January 2010 to August 30, 2020. We included studies on acute community-acquired pneumonia or acute lower respiratory tract infection with ≥1 year of continuous data collection; clear consistent case definition for pneumonia; >1 specimen type (except empyema studies where only pleural fluid was required); testing for >1 pathogen including both viruses and bacteria. Two researchers reviewed the studies independently. Results were presented as a narrative summary. Quality of evidence was assessed with the Quality Assessment Tool for Quantitative Studies. The study was registered on PROSPERO [CRD42020206830]. Results: We screened 5184 records; 1305 duplicates were removed. The remaining 3879 titles and abstracts were screened. Of these, 557 articles were identified for full-text review, and 55 met the inclusion criteria - 10 case-control studies, three post-mortem studies, 11 surveillance studies, eight cohort studies, five cross-sectional studies, 12 studies with another design and six studies that included patients with pleural effusions or empyema. Studies which described disease by severity showed higher bacterial detection (Streptococcus pneumoniae, Staphylococcus aureus) in severe vs non-severe cases. The most common virus causing severe disease was respiratory syncytial virus (RSV). Pathogens varied by age, with RSV and adenovirus more common in younger children. Influenza and atypical bacteria were more common in children 5-14 years than younger children. Malnourished and HIV-infected children had higher rates of pneumonia due to bacteria or tuberculosis. Conclusions: Several viral and bacterial pathogens were identified as important targets for prevention and treatment. Bacterial pathogens remain an important cause of moderate to severe disease, particularly in children with comorbidities despite widespread PCV and Hib vaccination.
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ItemPerformance of Xpert MTB/RIF and Mycobacterial Culture on Multiple Specimen Types for Diagnosis of Tuberculosis Disease in Young Children and Clinical Characterization According to Standardized Research Case Definitions.(Ovid Technologies (Wolters Kluwer Health), 2022-08-01)BACKGROUND: Tuberculosis (TB) is a leading cause of illness and death in children globally. Improved bacteriologic and clinical diagnostic approaches in children are urgently needed. METHODS: In a prospective cohort study, a consecutive series of young (<5 years) children presenting with symptoms suggestive of TB and parenchymal abnormality on chest radiograph in inpatient and outpatient settings in Kisumu County, Kenya from October 2013 to August 2015 were evaluated at baseline and over 6 months. Up to 14 specimens per child were tested for the Mycobacterium tuberculosis complex by fluorescence microscopy, Xpert MTB/RIF and mycobacterial culture. Using detailed clinical characterization, cases were retrospectively classified according to standardized research case definitions and the sensitivity and specificity of microbiological tests on different specimen types were determined. RESULTS: Among 300 young children enrolled, 266 had sufficient information to be classified according to the research clinical case definition. Of these, 36% (96/266) had TB disease; 32% (31/96) with bacteriologically confirmed intrathoracic TB. Compared to culture, the sensitivity of a single Xpert test ranged from 60 to 67% and specificity from 97.5 to 100% for different specimen types. CONCLUSIONS: Despite extensive specimen collection and laboratory testing, TB could not be bacteriologically confirmed in almost two-thirds of children with intrathoracic TB classified by research clinical case definitions. Improved diagnostic tests are needed to identify children with TB and to exclude other potential causes of illness.
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ItemThe Value of Chest Radiography in Tuberculosis Preventive Treatment (TPT) Screening in Children and Adolescents.(American Thoracic Society, 2022-06-02)
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ItemChildhood pneumonia in humanitarian emergencies in low- and middle-income countries: A systematic scoping review(INT SOC GLOBAL HEALTH, 2022-01-01)Background: Humanitarian emergencies increase many risk factors for pneumonia, including disruption to food, water and sanitation, and basic health services. This review describes pneumonia morbidity and mortality among children and adolescents affected by humanitarian emergencies. Methods: We searched MEDLINE, EMBASE, and PubMed databases for publications reporting pneumonia morbidity or mortality among children aged 1 month to 17 years in humanitarian emergencies (eg, natural disaster, armed conflict, displacement) in low- and middle-income countries (LMICs). Results: We included 22 papers published between January 2000 and July 2021 from 33 countries, involving refugee/displaced persons camps (n = 5), other conflict settings (n = 14), and natural disaster (n = 3). Population pneumonia incidence was high for children under 5 years of age (73 to 146 episodes per 100 patient-years); 6%-29% met World Health Organization (WHO) criteria for severe pneumonia requiring admission. Pneumonia accounted for 13%-34% of child and adolescent presentations to camp health facilities, 7%-48% of presentations and admissions to health facilities in other conflict settings, and 12%-22% of admissions to hospitals following natural disasters. Pneumonia related deaths accounted for 7%-30% of child and adolescent deaths in hospital, though case-fatality rates varied greatly (0.5%-17.2%). The risk for pneumonia was greater for children who are: recently displaced, living in crowded settings (particularly large camps), with deficient water and sanitation facilities, and those who are malnourished. Conclusion: Pneumonia is a leading cause of morbidity and mortality in children and adolescents affected by humanitarian emergencies. Future research should address population-based pneumonia burden, particularly for older children and adolescents, and describe contextual factors to allow for more meaningful interpretation and guide interventions.
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ItemEvolution and spread of a highly drug resistant strain of Mycobacterium tuberculosis in Papua New Guinea.(Springer Science and Business Media LLC, 2022-05-06)BACKGROUND: Molecular mechanisms determining the transmission and prevalence of drug resistant tuberculosis (DR-TB) in Papua New Guinea (PNG) are poorly understood. We used genomic and drug susceptibility data to explore the evolutionary history, temporal acquisition of resistance and transmission dynamics of DR-TB across PNG. METHODS: We performed whole genome sequencing on isolates from Central Public Health Laboratory, PNG, collected 2017-2019. Data analysis was done on a composite dataset that also included 100 genomes previously sequenced from Daru, PNG (2012-2015). RESULTS: Sampled isolates represented 14 of the 22 PNG provinces, the majority (66/94; 70%) came from the National Capital District (NCD). In the composite dataset, 91% of strains were Beijing 2.2.1.1, identified in 13 provinces. Phylogenetic tree of Beijing strains revealed two clades, Daru dominant clade (A) and NCD dominant clade (B). Multi-drug resistance (MDR) was repeatedly and independently acquired, with the first MDR cases in both clades noted to have emerged in the early 1990s, while fluoroquinolone resistance emerged in 2009 (95% highest posterior density 2000-2016). We identified the presence of a frameshift mutation within Rv0678 (p.Asp47fs) which has been suggested to confer resistance to bedaquiline, despite no known exposure to the drug. Overall genomic clustering was significantly associated with rpoC compensatory and inhA promoter mutations (p < 0.001), with high percentage of most genomic clusters (12/14) identified in NCD, reflecting its role as a potential national amplifier. CONCLUSIONS: The acquisition and evolution of drug resistance among the major clades of Beijing strain threaten the success of DR-TB treatment in PNG. With continued transmission of this strain in PNG, genotypic drug resistance surveillance using whole genome sequencing is essential for improved public health response to outbreaks. With occurrence of resistance to newer drugs such as bedaquiline, knowledge of full drug resistance profiles will be important for optimal treatment selection.
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ItemQuality of care for children with acute respiratory infections in health facilities: A comparative analysis of assessment tools(INT SOC GLOBAL HEALTH, 2022-01-01)Background: Severe childhood pneumonia requires treatment in hospital by trained health care workers. It is therefore important to determine if health facilities provide quality health services for children with acute respiratory infections (ARI), including pneumonia. Using established indicators from WHO to measure quality of care (QoC) as a reference standard, this review aims to evaluate how well existing tools assess QoC for children presenting to health facilities with ARI. Methods: Existing assessment tools identified from a published systematic literature review that evaluated QoC assessment tools for children (<15 years) in health facilities for all health conditions were included in this ARI-specific review. 27 ARI-specific indicators or "quality measures" from the WHO "Standards for improving quality of care for children and young adolescents in health facilities" were selected for use as a reference standard to assess QoC for children presenting to health facilities with ARI symptoms. Each included assessment tool was evaluated independently by two paediatricians to determine how many of the WHO ARI quality measures were assessable by the tool. The assessment tools were then ranked in order of percentage of ARI quality measures assessable. Results: Nine assessment tools that assessed QoC for children attending health facilities were included. Two hospital care tools developed by WHO had the most consistency with ARI-specific indicators, assessing 22/27 (81.5%) and 20/27 (74.1%) of the quality measures. The remaining tools were less consistent with the ARI-specific indicators, including between zero to 16 of the 27 quality measures. The most common indicators absent from the tools were assessment of appropriate use of pulse oximetry and administration of oxygen, how often oxygen supply was unavailable, and mortality rates. Conclusions: The existing WHO hospital-based QoC assessment tools are comprehensive but could be enhanced by improved data quality around oxygen availability and appropriate use of pulse oximetry and oxygen administration. Any tools, however, should be considered within broader assessments of QoC, rather than utilised in isolation. Further adaptation to local settings will improve feasibility and facilitate progress in the delivery of quality health care for children with ARI. Registration: The protocol of the original systematic review was registered in PROSPERO ID: CRD42020175652.
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ItemPreventive therapy in children exposed to Mycobacterium tuberculosis: problems and solutions(WILEY-BLACKWELL, 2012-10-01)Young children living with a tuberculosis patient are at high risk of Mycobacterium tuberculosis infection and disease. WHO guidelines promote active screening and isoniazid (INH) preventive therapy (PT) for such children under 5 years, yet this well-established intervention is seldom used in endemic countries. We review the literature regarding barriers to implementation of PT and find that they are multifactorial, including difficulties in screening, poor adherence, fear of increasing INH resistance and poor acceptability among primary caregivers and healthcare workers. These barriers are largely resolvable, and proposed solutions such as the adoption of symptom-based screening and shorter drug regimens are discussed. Integrated multicomponent and site-specific solutions need to be developed and evaluated within a public health framework to overcome the policy-practice gap and provide functional PT programmes for children in endemic settings.
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ItemMore Evidence to Support Screening of Child Contacts of Tuberculosis Cases: If Not Now, Then When?(OXFORD UNIV PRESS INC, 2013-12-15)
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ItemImportance of tuberculosis control to address child survival(ELSEVIER SCIENCE INC, 2014-05-03)