Sequential and parallel testing for microbiological confirmation of tuberculosis disease in children in five low-income and middle-income countries: a secondary analysis of the RaPaed-TB study.

BACKGROUND: Despite causing high mortality worldwide, paediatric tuberculosis is often undiagnosed. We aimed to investigate optimal testing strategies for microbiological confirmation of tuberculosis in children younger than 15 years, including the yield in high-risk subgroups (eg, children younger than 5 years, with HIV, or with severe acute malnutrition [SAM]). METHODS: For this secondary analysis, we used data from RaPaed-TB, a multicentre diagnostic accuracy study evaluating novel diagnostic assays and testing approaches for tuberculosis in children recruited from five health-care centres in Malawi, Mozambique, South Africa, Tanzania, and India conducted between Jan 21, 2019, and June 30, 2021. Children were included if they were younger than 15 years and had signs or symptoms of pulmonary or extrapulmonary tuberculosis; they were excluded if they weighed less than 2 kg, had received three or more doses of anti-tuberculosis medication at time of enrolment, were in a condition deemed critical by the local investigator, or if they did not have at least one valid microbiological result. We collected tuberculosis-reference specimens via spontaneous sputum, induced sputum, gastric aspirate, and nasopharyngeal aspirates. Microbiological tests were Xpert MTB/RIF Ultra (hereafter referred to as Ultra), liquid culture, and Löwenstein-Jensen solid culture, which were followed by confirmatory testing for positive cultures. The main outcome of this secondary analysis was categorising children as having confirmed tuberculosis if culture or Ultra positive on any sample, unconfirmed tuberculosis if clinically diagnosed, and unlikely tuberculosis if neither of these applied. FINDINGS: Of 5313 children screened, 975 were enrolled, of whom 965 (99%) had at least one valid microbiological result. 444 (46%) of 965 had unlikely tuberculosis, 282 (29%) had unconfirmed tuberculosis, and 239 (25%) had confirmed tuberculosis. Median age was 5·0 years (IQR 1·8-9·0); 467 (48%) of 965 children were female and 498 (52%) were male. 155 (16%) of 965 children had HIV and 110 (11%) children had SAM. 196 (82%) of 239 children with microbiological detection tested positive on Ultra. 110 (46%) of 239 were confirmed by both Ultra and culture, 86 (36%) by Ultra alone, and 43 (18%) by culture alone. 'Trace' was the most common semiquantitative result (93 [40%] of 234). 481 (50%) of 965 children had only one specimen type collected, 99 (21%) of whom had M tuberculosis detected. 484 (50%) of 965 children had multiple specimens collected, 141 (29%) of whom were positive on at least one specimen type. Of the 102 children younger than 5 years with M tuberculosis detected, 80 (78%) tested positive on sputum. 64 (80%) of 80 children who tested positive on sputum were positive on sputum alone; 61 (95%) of 64 were positive on induced sputum, two (3%) of 64 were positive on spontaneous sputum, and one (2%) was positive on both. INTERPRETATION: High rates of microbiological confirmation of tuberculosis in children can be achieved via parallel sampling and concurrent testing procedures. Sample types and choice of test to be used sequentially should be considered when applying to groups such as children younger than 5 years, living with HIV, or with SAM. FUNDING: European and Developing Countries Clinical Trials Partnership programme, supported by the EU, the UK Medical Research Council, Swedish International Development Cooperation Agency, Bundesministerium für Bildung und Forschung, the German Center for Infection Research, and Beckman Coulter.

Development of tuberculosis treatment decision algorithms in children below 5 years hospitalised with severe acute malnutrition in Zambia and Uganda: a prospective diagnostic cohort study.

Background: In children with severe acute malnutrition (SAM) tuberculosis is common, challenging to diagnose, and often fatal. We developed tuberculosis treatment decision algorithms (TDAs) for children under the age of 5 years with SAM. Methods: In this prospective diagnostic study, we enrolled and followed up children aged <60 months hospitalised with SAM at three tertiary hospitals in Zambia and Uganda from 4 November 2019 to 20 June 2022. We included children aged 2-59 months with SAM as defined by WHO and hospitalised following the WHO clinical criteria. We excluded children with current or history of antituberculosis treatment within the preceding 3 months. They underwent tuberculosis symptom screening, clinical assessment, chest X-ray, abdominal ultrasound, Xpert MTB/RIF Ultra (Ultra) and culture on respiratory and stool samples with 6 months follow-up. Tuberculosis was retrospectively defined using the 2015 standard case definition for childhood tuberculosis. We used logistic regression to develop diagnostic prediction models for a one-step diagnosis and a two-step screening and diagnostic approaches. We derived scores from models using WHO-recommended thresholds for sensitivity and proposed TDAs. This study is registered with ClinicalTrials.gov, NCT04240990. Findings: Of 1906 children hospitalised with SAM during the study period, 1230 were screened, 1152 were eligible and 603 were enrolled. Of the 603 children enrolled-median age 15 (inter-quartile range (IQR): 11-20) months and 65 (11.0%) living with HIV-114 (18.9%) were diagnosed with tuberculosis, including 51 (8.5%) with microbiological confirmation and 104 (17.2%) initiated treatment at a median of 6(IQR: 2-10) days after inclusion. 108 children were retrospectively classified as having tuberculosis resulting in a prevalence of 17.9% (95% confidence intervals (CI): 15.1; 21.2). 75 (69.4%) children with tuberculosis reported cough of any duration, 32 (29.6%) cough ≥2 weeks and 11 (10.2%) tuberculosis contact history. 535 children had complete data and were included in the diagnostic prediction model. The one-step diagnostic model had 15 predictors, including Ultra, clinical, radiographic, and abdominal features, an area under the receiving operating curve (AUROC) of 0.910, and derived TDA sensitivity of 86.14% (95% CI: 78.07-91.56) and specificity of 80.88% (95% CI: 76.91-84.30). The two-step model had AUROCs of 0.750 and 0.912 for screening and diagnosis, respectively, and derived combined TDA sensitivity of 79.21% (95% CI: 70.30-85.98) and a specificity of 83.64% (95% CI: 79.87-86.82). Interpretation: Tuberculosis prevalence was high among hospitalised children with SAM, with atypical clinical features. TDAs achieved satisfactory diagnostic accuracy and could be used to improve diagnosis in this vulnerable group. Funding: Unitaid.

Human cytomegalovirus deploys molecular mimicry to recruit VPS4A to sites of virus assembly.

The AAA-type ATPase VPS4 is recruited by proteins of the endosomal sorting complex required for transport III (ESCRT-III) to catalyse membrane constriction and membrane fission. VPS4A accumulates at the cytoplasmic viral assembly complex (cVAC) of cells infected with human cytomegalovirus (HCMV), the site where nascent virus particles obtain their membrane envelope. Here we show that VPS4A is recruited to the cVAC via interaction with pUL71. Sequence analysis, deep-learning structure prediction, molecular dynamics and mutagenic analysis identify a short peptide motif in the C-terminal region of pUL71 that is necessary and sufficient for the interaction with VPS4A. This motif is predicted to bind the same groove of the N-terminal VPS4A Microtubule-Interacting and Trafficking (MIT) domain as the Type 2 MIT-Interacting Motif (MIM2) of cellular ESCRT-III components, and this viral MIM2-like motif (vMIM2) is conserved across ß-herpesvirus pUL71 homologues. However, recruitment of VPS4A by pUL71 is dispensable for HCMV morphogenesis or replication and the function of the conserved vMIM2 during infection remains enigmatic. VPS4-recruitment via a vMIM2 represents a previously unknown mechanism of molecular mimicry in viruses, extending previous observations that herpesviruses encode proteins with structural and functional homology to cellular ESCRT-III components.

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

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

Machine learning enabled detection of COVID-19 pneumonia using exhaled breath analysis: a proof-of-concept study.

Detection of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) relies on real-time-reverse-transcriptase polymerase chain reaction (RT-PCR) on nasopharyngeal swabs. The false-negative rate of RT-PCR can be high when viral burden and infection is localized distally in the lower airways and lung parenchyma. An alternate safe, simple and accessible method for sampling the lower airways is needed to aid in the early and rapid diagnosis of COVID-19 pneumonia. In a prospective unblinded observational study, patients admitted with a positive RT-PCR and symptoms of SARS-CoV-2 infection were enrolled from three hospitals in Ontario, Canada. Healthy individuals or hospitalized patients with negative RT-PCR and without respiratory symptoms were enrolled into the control group. Breath samples were collected and analyzed by laser absorption spectroscopy (LAS) for volatile organic compounds (VOCs) and classified by machine learning (ML) approaches to identify unique LAS-spectra patterns (breathprints) for SARS-CoV-2. Of the 135 patients enrolled, 115 patients provided analyzable breath samples. Using LAS-breathprints to train ML classifier models resulted in an accuracy of 72.2%-81.7% in differentiating between SARS-CoV2 positive and negative groups. The performance was consistent across subgroups of different age, sex, body mass index, SARS-CoV-2 variants, time of disease onset and oxygen requirement. The overall performance was higher than compared to VOC-trained classifier model, which had an accuracy of 63%-74.7%. This study demonstrates that a ML-based breathprint model using LAS analysis of exhaled breath may be a valuable non-invasive method for studying the lower airways and detecting SARS-CoV-2 and other respiratory pathogens. The technology and the ML approach can be easily deployed in any setting with minimal training. This will greatly improve access and scalability to meet surge capacity; allow early and rapid detection to inform therapy; and offers great versatility in developing new classifier models quickly for future outbreaks.

A retroviral link to vertebrate myelination through retrotransposon-RNA-mediated control of myelin gene expression.

Myelin, the insulating sheath that surrounds neuronal axons, is produced by oligodendrocytes in the central nervous system (CNS). This evolutionary innovation, which first appears in jawed vertebrates, enabled rapid transmission of nerve impulses, more complex brains, and greater morphological diversity. Here, we report that RNA-level expression of RNLTR12-int, a retrotransposon of retroviral origin, is essential for myelination. We show that RNLTR12-int-encoded RNA binds to the transcription factor SOX10 to regulate transcription of myelin basic protein (Mbp, the major constituent of myelin) in rodents. RNLTR12-int-like sequences (which we name RetroMyelin) are found in all jawed vertebrates, and we further demonstrate their function in regulating myelination in two different vertebrate classes (zebrafish and frogs). Our study therefore suggests that retroviral endogenization played a prominent role in the emergence of vertebrate myelin.

In vitro modeling of the post-ingestion mobilization and bioaccessibility of pesticides sorbed to soil and house dust.

Soils and dusts can act as sinks for semivolatile lipophilic organic compounds and children ingest relatively large amounts of both soils and dusts. Following intake, sorbed chemicals may desorb (mobilize) and become available for intestinal absorption (bioaccessible). When chemicals are not degraded in the digestive tract, mobilization can approximate bioaccessibility. Alternatively, when gastrointestinal degradation of mobilized chemicals does occur, it can be useful to separate mobilization from bioaccessibility. In this study we used synthetic digestive fluids in a sequential, three-compartment (saliva, gastric, and intestinal) in vitro assay to construct mobilization and bioaccessibility models for 16 pesticides (log Kow 2.5-6.8) sorbed to 32 characterized soils and house dusts. To address the potential loss of mobilized pesticides due to absorption, the assays were repeated using a solid phase sorbent (tenax) added to the digestive fluid immediately after addition of the intestinal fluid components. We found that pesticide mobilization was predicted by pesticide log Kow and the carbon content of the soils and dusts. Pesticide loss measurably reduced the bioaccessibility of most pesticides, and bioaccessibility was largely predicted by log Kow and pesticide loss rate constants. Introduction of the sink increased mobilization by x̄ = 4 ± 6% (soil) and x̄ = 9 ± 7% (dust) while bioaccessibility increases were x̄ = 41 ± 21% (soil) and x̄ = 24 ± 12% (dust). The physicochemical properties of the soils, dusts, and pesticides used in this study successfully predicted the in vitro mobilization and bioaccessibility of the pesticides. This suggests that modeling of pesticide mobilization and bioaccessibility could reduce uncertainty in exposure and risk assessments.

Repurposing an endogenous degradation domain for antibody-mediated disposal of cell-surface proteins.

The exquisite specificity of antibodies can be harnessed to effect targeted degradation of membrane proteins. Here, we demonstrate targeted protein removal utilising a protein degradation domain derived from the endogenous human protein Proprotein Convertase Subtilisin/Kexin type 9 (PCSK9). Recombinant antibodies genetically fused to this domain drive the degradation of membrane proteins that undergo constitutive internalisation and recycling, including the transferrin receptor and the human cytomegalovirus latency-associated protein US28. We term this approach PACTAC (PCSK9-Antibody Clearance-Targeting Chimeras).

Pre-extensively Drug-Resistant Congenital Tuberculosis in an Extremely Premature Baby.

We describe a case of congenital tuberculosis in an extremely premature baby, with rapid molecular detection of a pre-extensively drug-resistant (XDR) pattern of drug resistance. The baby was treated successfully with a regimen including bedaquline and delamanid, drugs not previously described in the treatment of congenital tuberculosis (TB).

Diagnostic accuracy of a three-gene Mycobacterium tuberculosis host response cartridge using fingerstick blood for childhood tuberculosis: a multicentre prospective study in low-income and middle-income countries.

BACKGROUND: Childhood tuberculosis remains a major cause of morbidity and mortality in part due to missed diagnosis. Diagnostic methods with enhanced sensitivity using easy-to-obtain specimens are needed. We aimed to assess the diagnostic accuracy of the Cepheid Mycobacterium tuberculosis Host Response prototype cartridge (MTB-HR), a candidate test measuring a three-gene transcriptomic signature from fingerstick blood, in children with presumptive tuberculosis disease. METHODS: RaPaed-TB was a prospective diagnostic accuracy study conducted at four sites in African countries (Malawi, Mozambique, South Africa, and Tanzania) and one site in India. Children younger than 15 years with presumptive pulmonary or extrapulmonary tuberculosis were enrolled between Jan 21, 2019, and June 30, 2021. MTB-HR was performed at baseline and at 1 month in all children and was repeated at 3 months and 6 months in children on tuberculosis treatment. Accuracy was compared with tuberculosis status based on standardised microbiological, radiological, and clinical data. FINDINGS: 5313 potentially eligible children were screened, of whom 975 were eligible. 784 children had MTB-HR test results, of whom 639 had a diagnostic classification and were included in the analysis. MTB-HR differentiated children with culture-confirmed tuberculosis from those with unlikely tuberculosis with a sensitivity of 59·8% (95% CI 50·8-68·4). Using any microbiological confirmation (culture, Xpert MTB/RIF Ultra, or both), sensitivity was 41·6% (34·7-48·7), and using a composite clinical reference standard, sensitivity was 29·6% (25·4-34·2). Specificity for all three reference standards was 90·3% (95% CI 85·5-94·0). Performance was similar in different age groups and by malnutrition status. Among children living with HIV, accuracy against the strict reference standard tended to be lower (sensitivity 50·0%, 15·7-84·3) compared with those without HIV (61·0%, 51·6-69·9), although the difference did not reach statistical significance. Combining baseline MTB-HR result with one Ultra result identified 71·2% of children with microbiologically confirmed tuberculosis. INTERPRETATION: MTB-HR showed promising diagnostic accuracy for culture-confirmed tuberculosis in this large, geographically diverse, paediatric cohort and hard-to-diagnose subgroups. FUNDING: European and Developing Countries Clinical Trials Partnership, UK Medical Research Council, Swedish International Development Cooperation Agency, Bundesministerium für Bildung und Forschung; German Center for Infection Research (DZIF).

Effectiveness of a community-based approach for the investigation and management of children with household tuberculosis contact in Cameroon and Uganda: a cluster-randomised trial.

BACKGROUND: Globally, the uptake of tuberculosis-preventive treatment (TPT) among children with household tuberculosis contact remains low, partly due to the necessity of bringing children to health facilities for investigations. This study aimed to evaluate the effect on TPT initiation and completion of community-based approaches to tuberculosis contact investigations in Cameroon and Uganda. METHODS: We did a parallel, cluster-randomised, controlled trial across 20 clusters (consisting of 25 district hospitals and primary health centres) in Cameroon and Uganda, which were randomised (1:1) to receive a community-based approach (intervention group) or standard-of-care facility-based approach to contact screening and management (control group). The community-based approach consisted of symptom-based tuberculosis screening of all household contacts by community health workers at the household, with referral of symptomatic contacts to local facilities for investigations. Initiation of TPT (3-month course of rifampicin-isoniazid) was done by a nurse in the household, and home visits for TPT follow-up were done by community health workers. Index patients were people aged 15 years or older with bacteriologically confirmed, drug-susceptible, pulmonary tuberculosis diagnosed less than 1 month before inclusion and who declared at least one child or young adolescent (aged 0-14 years) household contact. The primary endpoint was the proportion of declared child contacts in the TPT target group (those aged <5 years irrespective of HIV status, and children aged 5-14 years living with HIV) who commenced and completed TPT, assessed in the modified intention-to-treat population (excluding enrolled index patients and their contacts who did not fit the eligibility criteria). Descriptive cascade of care assessment and generalised linear mixed modelling were used for comparison. This study is registered with ClinicalTrials.gov (NCT03832023). FINDINGS: The study included nine clusters in the intervention group (after excluding one cluster that did not enrol any index patients for >2 months) and ten in the control group. Between Oct 14, 2019 and Jan 13, 2022, 2894 child contacts were declared by 899 index patients with bacteriologically confirmed tuberculosis. Among all child contacts declared, 1548 (81·9%) of 1889 in the intervention group and 475 (47·3%) of 1005 in the control group were screened for tuberculosis. 1400 (48·4%) child contacts were considered to be in the TPT target group: 941 (49·8%) of 1889 in the intervention group and 459 (45·7%) of 1005 in the control group. In the TPT target group, TPT was commenced and completed in 752 (79·9%) of 941 child contacts in the intervention group and 283 (61·7%) of 459 in the control group (odds ratio 3·06 [95% CI 1·24-7·53]). INTERPRETATION: A community-based approach using community health workers can significantly increase contact investigation coverage and TPT completion among eligible child contacts in a tuberculosis-endemic setting. FUNDING: Unitaid. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

In vitro modeling of the post-ingestion bioaccessibility of per- and polyfluoroalkyl substances sorbed to soil and house dust.

Per- and polyfluoroalkyl substances (PFAS) are regularly found in soils and dusts, both of which can be consumed by children at relatively high amounts. However, there is little data available to model the bioaccessibility of PFAS in soils and dusts when consumed or to describe how the physiochemical properties of PFAS and soils/dusts might affect bioaccessibility of these chemicals. Because bioaccessibility is an important consideration in estimating absorbed dose for exposure and risk assessments, in the current study, in vitro assays were used to determine bioaccessibility of 14 PFAS in 33 sets of soils and dusts. Bioaccessibility assays were conducted with and without a sink, which was used to account for the removal of PFAS due to their movement across the human intestine. Multiple linear regression with backward elimination showed that a segmented model using PFAS chain length, number of branches, and percent total organic carbon explained 78.0%-88.9% of the variability in PFAS bioaccessibility. In general, PFAS had significantly greater bioaccessibility in soils relative to dusts and the addition of a sink increased bioaccessibility in the test system by as much as 10.8% for soils and 20.3% for dusts. The results from this study indicate that PFAS bioaccessibility in soils and dusts can be predicted using a limited set of physical chemical characteristics and could be used to inform risk assessment models.

The clinical presentation and detection of tuberculosis during pregnancy and in the postpartum period in low- and middle-income countries: A systematic review and meta-analysis.

For women infected with Mycobacterium tuberculosis, pregnancy is associated with an increased risk of developing or worsening TB disease. TB in pregnancy increases the risk of adverse maternal and neonatal outcomes, however the detection of TB in pregnancy is challenging. We aimed to identify and summarise the findings of studies regarding the clinical presentation and diagnosis of TB during pregnancy and the postpartum period (within 6 months of birth) in low-and middle-income countries (LMICs). A systematic review was conducted searching Ovid MEDLINE, Embase, CINAHL and Global Index Medicus databases. We included any primary research study of women diagnosed with TB during pregnancy or the postpartum period in LMICs that described the clinical presentation or method of diagnosis. Meta-analysis was used to determine pooled prevalence of TB clinical features and health outcomes, as well as detection method yield. Eighty-seven studies of 2,965 women from 27 countries were included. 70.4% of women were from South Africa or India and 44.7% were known to be HIV positive. For 1,833 women where TB type was reported, pulmonary TB was most common (79.6%). Most studies did not report the prevalence of presenting clinical features. Where reported, the most common were sputum production (73%) and cough (68%). Having a recent TB contact was found in 45% of women. Only six studies screened for TB using diagnostic testing for asymptomatic antenatal women and included mainly HIV-positive women ‒ 58% of women with bacteriologically confirmed TB did not report symptoms and only two were in HIV-negative women. Chest X-ray had the highest screening yield; 60% abnormal results of 3036 women tested. Screening pregnant women for TB-related symptoms and risk factors is important but detection yields are limited. Chest radiography and bacteriological detection methods can improve this, but procedures for optimal utilisation remain uncertain in this at-risk population. Trial registration: Prospero registration number: CRD42020202493.

Prevalence, clinical presentation and factors associated with chronic lung disease among children and adolescents living with HIV in Kenya.

INTRODUCTION: Children and adolescents with HIV (CAHIV) may experience recurrent and severe respiratory disease and are at risk of residual lung sequelae, and long-term morbidity from chronically damaged lungs. With improved survival due to increased access to effective antiretroviral therapy there is an increasing population of CAHIV who require optimal life-long care. Chronic lung disease in CAHIV is an under-recognised problem in African settings. We sought to determine the prevalence, clinical presentation and factors associated with chronic lung disease (CLD) among CAHIV in Kenya. METHODS: CAHIV aged ≤19 years in care at a public hospital in Nairobi were enrolled into a longitudinal cohort study. Sociodemographic and clinical information were obtained through interview, medical record review, physical examination and six-minute walk test. CD4 counts and viral load were determined. Enrolment data was analysed to determine baseline sociodemographic and clinical characteristics. Prevalence of CLD defined as presence of ≥2 respiratory symptoms or signs at enrolment was computed. Logistic regression analysis was performed to evaluate for association between various factors and presence or absence of CLD. RESULTS: We enrolled 320 CAHIV of median age 13 (IQR 10-16) years, 80 (25%) were <10 years, 46% were female, 31% lived in a one-room house and 51% used polluting cooking fuel. Antiretroviral therapy (ART) was initiated after age five years in 56%, 43% had prior pneumonia or tuberculosis, 11% had low CD4 count and 79% were virologically suppressed. Common respiratory symptoms and signs were exertional breathlessness (40%), chronic cough (23%), chest problems in the preceding year (24%), tachypnoea (52%), finger clubbing (6%), exercise limitation (59%) and oxygen desaturation during exercise (7%). CLD was present in 82 (26%) participants, and adding the six-minute walk distance <70% of predicted (exercise limitation) identified an additional 28 (9%) CAHIV with CLD. CLD was more common among older teenagers (odds ratio (OR) 1.95), those who had prior TB or pneumonia (OR 2.04), delayed initiation of ART (OR 2.60), cotrimoxazole prophylaxis (OR 3.35) or TB preventive therapy (OR 2.81). CLD was associated with viraemia (OR 2.7), lower quality of life (OR 12.7), small houses (OR 2.05), caregiver having fewer years of education (OR 2.46), outdoor pollution exposure (OR 3.31) and lower use of polluting cooking fuel indoors (OR 0.26). Adjusted analysis revealed CLD to be associated with prior tuberculosis or pneumonia (adjusted OR (aOR) [95%CI] 2.15 [1.18-3.91]), small house (aOR 1.95 [1.02-3.73]), lower use of polluting cooking fuel (aOR 0.35 [0.13-0.94]) and negative impact on health-related quality of life (aOR 6.91 [3.66-13.03]). CONCLUSIONS: CLD is highly prevalent across the age spectrum of CAHIV, and most are symptomatic with cough or exertional breathlessness. CLD is associated with prior tuberculosis or pneumonia, socio-environmental factors, and lower quality of life. Structured interventions are needed to provide optimal care specific to their needs.

Clinical algorithm reduces antibiotic use among children presenting with respiratory symptoms to hospital in central Vietnam.

OBJECTIVE: To assess the safety and utility of a pragmatic clinical algorithm to guide rational antibiotic use in children presenting with respiratory infection. METHODS: The effect of an algorithm to guide the management of young (< 5 years) children presenting with respiratory symptoms to the Da Nang Hospital for Women and Children, Vietnam, was evaluated in a before-after intervention analysis. The main outcome was reduction in antibiotic use, with monitoring of potential harm resulting from reduced antibiotic use. The intervention comprised a single training session of physicians in the use of an algorithm informed by local evidence; developed during a previous prospective observational study. The evaluation was performed one month after the training. RESULTS: Of the 1290 children evaluated before the intervention, 102 (7.9%) were admitted to hospital and 556/1188 (46.8%) were sent home with antibiotics. Due to COVID-19, only 166 children were evaluated after the intervention of whom 14 (8.4%) were admitted to hospital and 54/152 (35.5%) were sent home with antibiotics. Antibiotic use was reduced (from 46.8% to 35.5%; p = 0.009) after clinician training, but adequate comparison was compromised. The reduction was most pronounced in children with wheeze or runny nose and no fever, or a normal chest radiograph, where antibiotic use declined from 46.7% to 28.8% (p < 0.0001). The frequency of repeat presentation to hospital was similar between the two study periods (141/1188; 11.9% before and 10/152; 6.6% after; p = 0.10). No child represented with serious disease after being sent home without antibiotics. CONCLUSIONS: We observed a reduction in antibiotic use in young children with a respiratory infection after physician training in the use of a simple evidence-based management algorithm. However, the study was severely impacted by COVID-19 restrictions, requiring further evaluation to confirm the observed effect.

Attenuation hotspots in neurotropic human astroviruses.

During the last decade, the detection of neurotropic astroviruses has increased dramatically. The MLB genogroup of astroviruses represents a genetically distinct group of zoonotic astroviruses associated with gastroenteritis and severe neurological complications in young children, the immunocompromised, and the elderly. Using different virus evolution approaches, we identified dispensable regions in the 3' end of the capsid-coding region responsible for attenuation of MLB astroviruses in susceptible cell lines. To create recombinant viruses with identified deletions, MLB reverse genetics (RG) and replicon systems were developed. Recombinant truncated MLB viruses resulted in imbalanced RNA synthesis and strong attenuation in iPSC-derived neuronal cultures confirming the location of neurotropism determinants. This approach can be used for the development of vaccine candidates using attenuated astroviruses that infect humans, livestock animals, and poultry.

Antimicrobial stewardship in the era of the COVID-19 pandemic: A systematic review protocol on the opportunities and challenges for Sub-Saharan Africa.

BACKGROUND: Antimicrobial resistance (AMR) remains one of the leading threats to global public health and this may increase following COVID-19 pandemic. This is particularly the case in Africa where regulations on antimicrobial usage are weak. This protocol outlines the steps to undertake a systematic review to synthesize evidence on drivers of AMR and evaluate existing approaches to strengthening antimicrobial stewardship (AMS) programs in Sub-Saharan Africa (SSA). On the basis of the evidence generated from the evidence synthesis, the overarching goal of this work is to provide recommendations to support best practices in AMS implementation in SSA. METHODS: A systematic search will be conducted using the following databases: Global Health Library, PubMed, Cumulative Index to Nursing and Allied Health Literature, Scopus, Google Scholar, Global Health, Embase, African Journals Online Library, Web of Science, antimicrobial databases (WHO COVID-19, TrACSS, NDARO, and JPIAMR), and the Cochrane databases for systematic reviews. Studies will be included if they assess AMR and AMS in SSA from January 2000 to January 31, 2023. RESULTS: The primary outcomes will include the drivers of AMR and approaches to AMS implementation in SSA. The Preferred Reporting Items for Systematic Reviews and Meta-analyses will guide the reporting of this systematic review. CONCLUSIONS: The findings are expected to provide evidence on best practices and resource sharing for policy consideration to healthcare providers and other stakeholders both at the local and international levels. Additionally, the study seeks to establish drivers specific to AMR during the COVID-19 era in the SSA, for example, with the observed increasing trend of antimicrobial misuse during the first or second year of the pandemic may provide valuable insights for policy recommendation in preparedness and response measures to future pandemics. PROSPERO REGISTRATION NUMBER: CRD42022368853.

Beyond patient delay, navigating structural health system barriers to timely care and treatment in a high burden TB setting in Papua New Guinea.

Tuberculosis (TB) is a major public health issue in Papua New Guinea, with incidence rates particularly high in the South Fly District of Western Province. We present three case studies, along with additional vignettes, that were derived from interviews and focus groups carried out between July 2019 and July 2020 of people living in rural areas of the remote South Fly District depicting their challenges accessing timely TB diagnosis and care; most services within the district are only offered offshore on Daru Island. The findings detail that rather than 'patient delay' attributed to poor health seeking behaviours and inadequate knowledge of TB symptoms, many people were actively trying to navigate structural barriers hindering access to and utilisation of limited local TB services. The findings highlight a fragile and fragmented health system, a lack of attention given to primary health services, and undue financial burdens placed on people living in rural and remote areas associated with costly transportation to access functioning health services. We conclude that a person-centred and effective decentralised model of TB care as outlined in health policies is imperative for equitable access to essential health care services in Papua New Guinea.

Development of treatment-decision algorithms for children evaluated for pulmonary tuberculosis: an individual participant data meta-analysis.

BACKGROUND: Many children with pulmonary tuberculosis remain undiagnosed and untreated with related high morbidity and mortality. Recent advances in childhood tuberculosis algorithm development have incorporated prediction modelling, but studies so far have been small and localised, with limited generalisability. We aimed to evaluate the performance of currently used diagnostic algorithms and to use prediction modelling to develop evidence-based algorithms to assist in tuberculosis treatment decision making for children presenting to primary health-care centres. METHODS: For this meta-analysis, we identified individual participant data from a WHO public call for data on the management of tuberculosis in children and adolescents and referral from childhood tuberculosis experts. We included studies that prospectively recruited consecutive participants younger than 10 years attending health-care centres in countries with a high tuberculosis incidence for clinical evaluation of pulmonary tuberculosis. We collated individual participant data including clinical, bacteriological, and radiological information and a standardised reference classification of pulmonary tuberculosis. Using this dataset, we first retrospectively evaluated the performance of several existing treatment-decision algorithms. We then used the data to develop two multivariable prediction models that included features used in clinical evaluation of pulmonary tuberculosis-one with chest x-ray features and one without-and we investigated each model's generalisability using internal-external cross-validation. The parameter coefficient estimates of the two models were scaled into two scoring systems to classify tuberculosis with a prespecified sensitivity target. The two scoring systems were used to develop two pragmatic, treatment-decision algorithms for use in primary health-care settings. FINDINGS: Of 4718 children from 13 studies from 12 countries, 1811 (38·4%) were classified as having pulmonary tuberculosis: 541 (29·9%) bacteriologically confirmed and 1270 (70·1%) unconfirmed. Existing treatment-decision algorithms had highly variable diagnostic performance. The scoring system derived from the prediction model that included clinical features and features from chest x-ray had a combined sensitivity of 0·86 [95% CI 0·68-0·94] and specificity of 0·37 [0·15-0·66] against a composite reference standard. The scoring system derived from the model that included only clinical features had a combined sensitivity of 0·84 [95% CI 0·66-0·93] and specificity of 0·30 [0·13-0·56] against a composite reference standard. The scoring system from each model was placed after triage steps, including assessment of illness acuity and risk of poor tuberculosis-related outcomes, to develop treatment-decision algorithms. INTERPRETATION: We adopted an evidence-based approach to develop pragmatic algorithms to guide tuberculosis treatment decisions in children, irrespective of the resources locally available. This approach will empower health workers in primary health-care settings with high tuberculosis incidence and limited resources to initiate tuberculosis treatment in children to improve access to care and reduce tuberculosis-related mortality. These algorithms have been included in the operational handbook accompanying the latest WHO guidelines on the management of tuberculosis in children and adolescents. Future prospective evaluation of algorithms, including those developed in this work, is necessary to investigate clinical performance. FUNDING: WHO, US National Institutes of Health.