50 research outputs found

    Safety and immunogenicity of radiation-attenuated PfSPZ vaccine in equatoguinean infants, children, and adults

    Get PDF
    The radiation-attenuated Plasmodium falciparum sporozoites (PfSPZ) Vaccine has demonstrated safety and immunogenicity in 5-month-old to 50-year-old Africans in multiple trials. Except for one, each trial has restricted enrollment to either infants and children or adults /= 0.17). There were no significant differences between vaccinees and controls with respect to the rates or severity of unsolicited AEs or laboratory abnormalities. Development of antibodies to P. falciparum circumsporozoite protein occurred in 67/69 vaccinees (97%) and 0/15 controls. Median antibody levels were highest in infants and 1-5-year-olds and declined progressively with age. Antibody responses in children were greater than in adults protected against controlled human malaria infection. Robust immunogenicity, combined with a benign AE profile, indicates children are an ideal target for immunization with PfSPZ Vaccine

    Planned delivery or expectant management for late preterm pre-eclampsia in low-income and middle-income countries (CRADLE-4): a multicentre, open-label, randomised controlled trial

    Get PDF
    Background: Pre-eclampsia is a leading cause of maternal and perinatal mortality. Evidence regarding interventions in a low-income or middle-income setting is scarce. We aimed to evaluate whether planned delivery between 34+ 0 and 36+ 6 weeks’ gestation can reduce maternal mortality and morbidity without increasing perinatal complications in India and Zambia. / Methods: In this parallel-group, multicentre, open-label, randomised controlled trial, we compared planned delivery versus expectant management in women with pre-eclampsia from 34+ 0 to 36+ 6 weeks’ gestation. Participants were recruited from nine hospitals and referral facilities in India and Zambia and randomly assigned to planned delivery or expectant management in a 1:1 ratio by a secure web-based randomisation facility hosted by MedSciNet. Randomisation was stratified by centre and minimised by parity, single-fetus pregnancy or multi-fetal pregnancy, and gestational age. The primary maternal outcome was a composite of maternal mortality or morbidity with a superiority hypothesis. The primary perinatal outcome was a composite of one or more of: stillbirth, neonatal death, or neonatal unit admission of more than 48 h with a non-inferiority hypothesis (margin of 10% difference). Analyses were by intention to treat, with an additional per-protocol analysis for the perinatal outcome. The trial was prospectively registered with ISRCTN, 10672137. The trial is closed to recruitment and all follow-up has been completed. / Findings: Between Dec 19, 2019, and March 31, 2022, 565 women were enrolled. 284 women (282 women and 301 babies analysed) were allocated to planned delivery and 281 women (280 women and 300 babies analysed) were allocated to expectant management. The incidence of the primary maternal outcome was not significantly different in the planned delivery group (154 [55%]) compared with the expectant management group (168 [60%]; adjusted risk ratio [RR] 0·91, 95% CI 0·79 to 1·05). The incidence of the primary perinatal outcome by intention to treat was non-inferior in the planned delivery group (58 [19%]) compared with the expectant management group (67 [22%]; adjusted risk difference –3·39%, 90% CI –8·67 to 1·90; non-inferiority p<0·0001). The results from the per-protocol analysis were similar. There was a significant reduction in severe maternal hypertension (adjusted RR 0·83, 95% CI 0·70 to 0·99) and stillbirth (0·25, 0·07 to 0·87) associated with planned delivery. There were 12 serious adverse events in the planned delivery group and 21 in the expectant management group. / Interpretation: Clinicians can safely offer planned delivery to women with late preterm pre-eclampsia, in a low-income or middle-income country. Planned delivery reduces stillbirth, with no increase in neonatal unit admissions or neonatal morbidity and reduces the risk of severe maternal hypertension. Planned delivery from 34 weeks’ gestation should therefore be considered as an intervention to reduce pre-eclampsia associated mortality and morbidity in these settings. / Funding: UK Medical Research Council and Indian Department of Biotechnology

    Biofortified Maize Improves Selenium Status of Women and Children in a Rural Community in Malawi: Results of the Addressing Hidden Hunger With Agronomy Randomized Controlled Trial

    Get PDF
    Background: Selenium deficiency is widespread in the Malawi population. The selenium concentration in maize, the staple food crop of Malawi, can be increased by applying selenium-enriched fertilizers. It is unknown whether this strategy, called agronomic biofortification, is effective at alleviating selenium deficiency. Objectives: The aim of the Addressing Hidden Hunger with Agronomy (AHHA) trial was to determine whether consumption of maize flour, agronomically-biofortified with selenium, affected the serum selenium concentrations of women, and children in a rural community setting. Design: An individually-randomized, double-blind placebo-controlled trial wasconducted in rural Malawi. Participants were randomly allocated in a 1:1 ratio to receive either intervention maize flour biofortified with selenium through application of selenium fertilizer, or control maize flour not biofortified with selenium. Participant households received enough flour to meet the typical consumption of all household members (330 g capita−1 day−1) for a period of 8 weeks. Baseline and endline serum selenium concentration (the primary outcome) was measured by inductively coupled plasma mass spectrometry (ICP-MS). Results: One woman of reproductive age (WRA) and one school-aged child (SAC) from each of 180 households were recruited and households were randomized to each group. The baseline demographic and socioeconomic status of participants were well-balanced between arms. No serious adverse events were reported. In the intervention arm, mean (standard deviation) serum selenium concentration increased over the intervention period from 57.6 (17.0) μg L−1 (n = 88) to 107.9 (16.4) μg L−1 (n = 88) among WRA and from 46.4 (14.8) μg L−1 (n = 86) to 97.1 (16.0) μg L−1 (n = 88) among SAC. There was no evidence of change in serum selenium concentration in the control groups Conclusion: Consumption of maize flour biofortified through application of selenium-enriched fertilizer increased selenium status in this community providing strong proof of principle that agronomic biofortification could be an effective approach to address selenium deficiency in Malawi and similar settings. Clinical Trial Registration http://www.isrctn.com/ISRCTN85899451, identifier: ISRCTN85899451

    Farmer experiences of Tiyeni’s ‘deep-bed farming’ conservation agriculture system in Malawi

    Get PDF
    In the context of increasing NGO interest in the capacity of conservation agriculture methods to support sustainable agriculture across sub-Saharan Africa, this paper explores the experiences of farmers (n = 111) adopting the Tiyeni NGO’s deep-bed farming (DBF) system in northern Malawi. The results of a field survey suggest that whilst DBF delivers significant livelihood benefits for farmers relative to traditional techniques (a factor arguably driving its rapid spontaneous adoption throughout the area), some asset-poor farmers are unable to sustain DBF due to its labor demands. We argue that to widen its beneficial impacts in a manner that can be sustained, there is a need for Tiyeni’s DBF to be less prescriptive and more adaptive to specific social-ecological contexts

    The Gene Ontology resource: enriching a GOld mine

    Get PDF
    The Gene Ontology Consortium (GOC) provides the most comprehensive resource currently available for computable knowledge regarding the functions of genes and gene products. Here, we report the advances of the consortium over the past two years. The new GO-CAM annotation framework was notably improved, and we formalized the model with a computational schema to check and validate the rapidly increasing repository of 2838 GO-CAMs. In addition, we describe the impacts of several collaborations to refine GO and report a 10% increase in the number of GO annotations, a 25% increase in annotated gene products, and over 9,400 new scientific articles annotated. As the project matures, we continue our efforts to review older annotations in light of newer findings, and, to maintain consistency with other ontologies. As a result, 20 000 annotations derived from experimental data were reviewed, corresponding to 2.5% of experimental GO annotations. The website (http://geneontology.org) was redesigned for quick access to documentation, downloads and tools. To maintain an accurate resource and support traceability and reproducibility, we have made available a historical archive covering the past 15 years of GO data with a consistent format and file structure for both the ontology and annotations

    Development and validation of quantitative PCR assays for HIV-associated cryptococcal meningitis in sub-Saharan Africa: a diagnostic accuracy study

    Get PDF
    Background: HIV-associated cryptococcal meningitis is the second leading cause of AIDS-related deaths, with a 10-week mortality rate of 25–30%. Fungal load assessed by colony-forming unit (CFU) counts is used as a prognostic marker and to monitor response to treatment in research studies. PCR-based assessment of fungal load could be quicker and less labour-intensive. We sought to design, optimise, and validate quantitative PCR (qPCR) assays for the detection, identification, and quantification of Cryptococcus infections in patients with cryptococcal meningitis in sub-Saharan Africa. Methods: We developed and validated species-specific qPCR assays based on DNA amplification of QSP1 (QSP1A specific to Cryptococcus neoformans, QSP1B/C specific to Cryptococcus deneoformans, and QSP1D specific to Cryptococcus gattii species) and a pan-Cryptococcus assay based on a multicopy 28S rRNA gene. This was a longitudinal study that validated the designed assays on cerebrospinal fluid (CSF) of 209 patients with cryptococcal meningitis at baseline (day 0) and during anti-fungal therapy (day 7 and day 14), from the AMBITION-cm trial in Botswana and Malawi (2018–21). Eligible patients were aged 18 years or older and presenting with a first case of cryptococcal meningitis. Findings: When compared with quantitative cryptococcal culture as the reference, the sensitivity of the 28S rRNA was 98·2% (95% CI 95·1–99·5) and of the QSP1 assay was 90·4% (85·2–94·0) in CSF at day 0. Quantification of the fungal load with QSP1 and 28S rRNA qPCR correlated with quantitative cryptococcal culture (R2=0·73 and R2=0·78, respectively). Both Botswana and Malawi had a predominant C neoformans prevalence of 67% (95% CI 55–75) and 68% (57–73), respectively, and lower C gattii rates of 21% (14–31) and 8% (4–14), respectively. We identified ten patients that, after 14 days of treatment, harboured viable but non-culturable yeasts based on QSP1 RNA detection (without any positive CFU in CSF culture). Interpretation: QSP1 and 28S rRNA assays are useful in identifying Cryptococcus species. qPCR results correlate well with baseline quantitative cryptococcal culture and show a similar decline in fungal load during induction therapy. These assays could be a faster alternative to quantitative cryptococcal culture to determine fungal load clearance. The clinical implications of the possible detection of viable but non-culturable cells in CSF during induction therapy remain unclear. Funding: European and Developing Countries Clinical Trials Partnership; Swedish International Development Cooperation Agency; Wellcome Trust/UK Medical Research Council/UKAID Joint Global Health Trials; and UK National Institute for Health Research

    Development and validation of quantitative PCR assays for HIV-associated cryptococcal meningitis in sub-Saharan Africa: a diagnostic accuracy study

    Get PDF
    Background: HIV-associated cryptococcal meningitis is the second leading cause of AIDS-related deaths, with a 10-week mortality rate of 25–30%. Fungal load assessed by colony-forming unit (CFU) counts is used as a prognostic marker and to monitor response to treatment in research studies. PCR-based assessment of fungal load could be quicker and less labour-intensive. We sought to design, optimise, and validate quantitative PCR (qPCR) assays for the detection, identification, and quantification of Cryptococcus infections in patients with cryptococcal meningitis in sub-Saharan Africa. Methods: We developed and validated species-specific qPCR assays based on DNA amplification of QSP1 (QSP1A specific to Cryptococcus neoformans, QSP1B/C specific to Cryptococcus deneoformans, and QSP1D specific to Cryptococcus gattii species) and a pan-Cryptococcus assay based on a multicopy 28S rRNA gene. This was a longitudinal study that validated the designed assays on cerebrospinal fluid (CSF) of 209 patients with cryptococcal meningitis at baseline (day 0) and during anti-fungal therapy (day 7 and day 14), from the AMBITION-cm trial in Botswana and Malawi (2018–21). Eligible patients were aged 18 years or older and presenting with a first case of cryptococcal meningitis. Findings: When compared with quantitative cryptococcal culture as the reference, the sensitivity of the 28S rRNA was 98·2% (95% CI 95·1–99·5) and of the QSP1 assay was 90·4% (85·2–94·0) in CSF at day 0. Quantification of the fungal load with QSP1 and 28S rRNA qPCR correlated with quantitative cryptococcal culture (R2=0·73 and R2=0·78, respectively). Both Botswana and Malawi had a predominant C neoformans prevalence of 67% (95% CI 55–75) and 68% (57–73), respectively, and lower C gattii rates of 21% (14–31) and 8% (4–14), respectively. We identified ten patients that, after 14 days of treatment, harboured viable but non-culturable yeasts based on QSP1 RNA detection (without any positive CFU in CSF culture). Interpretation: QSP1 and 28S rRNA assays are useful in identifying Cryptococcus species. qPCR results correlate well with baseline quantitative cryptococcal culture and show a similar decline in fungal load during induction therapy. These assays could be a faster alternative to quantitative cryptococcal culture to determine fungal load clearance. The clinical implications of the possible detection of viable but non-culturable cells in CSF during induction therapy remain unclear

    Plasmodium falciparum malaria and invasive bacterial co-infection in young African children: the dysfunctional spleen hypothesis

    Full text link
    corecore