15 research outputs found

    Maternal Latent Mycobacterium tuberculosis Does Not Affect the Infant Immune Response Following BCG at Birth: An Observational Longitudinal Study in Uganda

    Get PDF
    Background: BCG has low efficacy in tropical countries. We hypothesized that maternal latent Mycobacterium tuberculosis (M.tb) infection (LTBI) results in fetal tolerance to mycobacterial antigens and impaired responses to BCG immunization. Methods: We enrolled 132 LTBI-positive and 150 LTBI-negative mothers and their babies in Entebbe, Uganda. Infants were BCG-immunized at birth. Cord blood and samples at weeks 1, 4, 6, 10, 14, 24, and 52 were analyzed for cytokine/chemokine responses to M.tb antigens by Luminex 17-plex assay in 6-day whole blood cultures and antibody responses by ELISA. Of the 17 Luminex analytes, seven (IL-2, IL-5, IL-10, IL-13, IL-17A, TNF, and IFN-γ) were included in the main analysis as they were considered most likely to represent T cell responses. Immune sensitization was defined as a detectable cord blood cytokine response to PPD for any of the seven cytokines. Patterns of cytokine and antibody responses were compared between infants of mothers with and without LTBI using linear mixed models adjusting for confounders. Results: Most infants (73%) were sensitized in utero to M.tb antigens, with no overall difference seen between infants born to mothers with or without LTBI. Patterns of post-BCG cytokine and antibody responses to mycobacterial antigens were similar between the two infant groups. Conclusions: Our data do not support the hypothesis that maternal LTBI results in an impaired response to BCG immunization, in Ugandan infants. BCG vaccination at or shortly after birth is likely to be beneficial to all infants, irrespective of maternal LTBI status.UK Medical Research Council; DELTAS Africa Initiative SSACAB; DELTAS Initiative MUIIplus; Commonwealth Scholarships Commission; MRC/UVRI and LSHTM Uganda Research Unit; EU Horizon 2020 programme; MRC London Intercollegiate Doctoral Training Partnership; MRC; UK Medical Research Council (MRC); UK Department for International Development (DFID)

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

    Get PDF
    INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

    Using biodiversity data to review coverage of Uganda's protected areas

    No full text
    This paper seeks to demonstrate the usefulness of the data held at the National Biodiversity Data Bank (NBDB) situated at Makerere University Institute of Environment and Natural Resources (MUIENR). We assess its value as a potential planning tool, based on the growing evidence that Uganda aspires to a robust Protected Area system that encompasses protection of biodiversity at the genetic, species and ecosystem levels. Analyses are presented of the coverage of 21 major vegetation types, and of species of birds and mammals. Several important vegetation types are inadequately conserved, whilst coverage of some categories of birds is also incomplete. The situation seems to be worse for mammals, although this is harder to assess because the distributions of many species are poorly known. .Journal of East African Natural History Vol. 88 (1&2) 1999: pp. 41-5

    Content-Based Image Retrieval Using Combined 2D Attribute Pattern Spectra

    No full text
    This work proposes a region-based shape signature that uses a combination of three different types of pattern spectra. The proposed method is inspired by the connected shape filter proposed by Urbach et al. We extract pattern spectra from the red, green and blue color bands of an image then incorporate machine learning techniques for application in photographic image retrieval. Our experiments show that the combined pattern spectrum gives an improvement of approximately 30% in terms of mean average precision and precision at 20 with respect to Urbach et al’s method

    Cooking banana marketing protocol (Runyankole).

    Get PDF
    This protocol is designed to support farmers to improve the quality of their bananas in the field and the postharvest practices in a bid to facilitate access to better prices and niche markets. The protocol is organized into three sections: Section 1 Good Agricultural Practices (GAP); Section 2: Proper Harvest and Handling Practices and Section 3: Good Marketing Practices (GMP)

    Cooking banana marketing protocol (Luganda).

    Get PDF
    This protocol is designed to support farmers to improve the quality of their bananas in the field and the postharvest practices in a bid to facilitate access to better prices and niche markets. The protocol is organized into three sections: Section 1 Good Agricultural Practices (GAP); Section 2: Proper Harvest and Handling Practices and Section 3: Good Marketing Practices (GMP)

    Comparison of the Novel Oral Anticoagulants Apixaban, Dabigatran, Edoxaban, and Rivaroxaban in the Initial and Long-Term Treatment and Prevention of Venous Thromboembolism: Systematic Review and Network Meta-Analysis

    No full text
    <div><p>Background</p><p>Anticoagulation with low molecular weight heparin and vitamin K antagonists is the current standard of care (SOC) for venous thromboembolism (VTE) treatment and prevention. Although novel oral anti-coagulants (NOACs) have been compared with SOC in this indication, no head-to-head randomised controlled trials (RCTs) have directly compared NOACs. A systematic review and network meta-analysis (NMA) were conducted to compare the efficacy and safety of NOACs for the initial and long-term treatment of VTE.</p><p>Methods</p><p>Electronic databases (accessed July 2014) were systematically searched to identify RCTs evaluating apixaban, dabigatran, edoxaban, and rivaroxaban versus SOC. Eligible patients included adults with an objectively confirmed deep vein thrombosis (DVT), pulmonary embolism (PE) or both. A fixed-effect Bayesian NMA was conducted for outcomes of interest, and results were presented as relative risks (RR) and 95% credible intervals (Crl).</p><p>Results</p><p>Six Phase III RCTs met criteria for inclusion: apixaban (one RCT; n = 5,395); rivaroxaban (two RCTs; n = 3,423/4,832); dabigatran (two RCTs; n = 2,539/2,568); edoxaban (one RCT; n = 8,240). There were no statistically significant differences between the NOACs with regard to the risk of ‘VTE and VTE-related death. Apixaban treatment was associated with the most favourable safety profile of the NOACs, showing a statistically significantly reduced risk of ‘major or clinically relevant non-major (CRNM) bleed’ compared with rivaroxaban (0.47 [0.36, 0.61]), dabigatran (0.69 [0.51, 0.94]), and edoxaban (0.54 [0.41, 0.69]). Dabigatran was also associated with a significantly lower risk of ‘major or CRNM bleed’ compared with rivaroxaban (0.68 [0.53, 0.87]) and edoxaban (0.77 [0.60, 0.99]).</p><p>Conclusions</p><p>Indirect comparisons showed statistically similar reductions in the risk of ‘VTE or VTE-related death for all NOACs. In contrast, reductions in ‘major or CRNM bleed’ for initial/long-term treatment were significantly better with apixaban compared with all other NOACs, and with dabigatran compared with rivaroxaban and edoxaban. Results from the current analysis indicate that the NOACs offer clinical benefit over conventional therapy while highlighting relative differences in their bleeding profile.</p></div

    Systematic review flow diagram.

    No full text
    <p>The flow diagram indicates inclusion and exclusion of publications at each stage of the systematic review process. †An updated search was conducted in April 2016. No additional eligible publications were identified.</p

    Network of evidence for the meta-analysis.

    No full text
    <p>†Primary and sensitivity analyses used pooled data from the EINSTEIN DVT and EINSTEIN PE trials [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0144856#pone.0144856.ref028" target="_blank">28</a>].</p
    corecore