121 research outputs found
Mortality under early access to antiretroviral therapy vs Eswatiniâs national standard of care : the MaxART clustered randomized steppedâwedge trial
Objectives Current WHO guidelines recommend the treatment of all HIV-infected individuals with antiretroviral therapy (ART) to improve survival and quality of life, and decrease infection of others. MaxART is the first implementation trial of this strategy embedded within a government-managed health system, and assesses mortality as a secondary outcome. Because primary findings strongly supported scale-up of the 'treat all' strategy (hereafter Treat All), this analysis examines mortality as an additional indicator of its impact.
Methods MaxART was conducted in 14 Eswatinian health clinics through a clinic-based stepped-wedge design, by transitioning clinics from then-national standard of care (SoC) to the Treat All intervention. All-cause, disease-related, and HIV-related mortality were analysed using the Cox proportional hazards model, censoring SoC participants at clinic transition. Median follow-up time among study participants was 292 days. There were 36/2034 deaths in SoC (1.77%) and 49/1371 deaths in Treat All (3.57%).
Results Between September 2014 and August 2017, 3405 participants were enrolled. In SoC and Treat All interventions, respectively, the multivariable-adjusted 12-month all-cause mortality rates were 1.42% [95% confidence interval (CI): 0.66-2.17] and 1.60% (95% CI: 0.78-2.40), disease-related mortality rates were 1.02% (95% CI: 0.40-1.64) and 1.10% (95% CI: 0.46-1.73), and HIV-related mortality rates were 1.03% (95% CI: 0.40-1.65) and 0.99% (95% CI: 0.40-1.58). Treat All had no impact on all-cause [hazard ratio (HR) = 1.12, 95% CI: 0.58-2.18, P = 0.73], disease-related (HR = 1.04, 95% CI: 0.52-2.11, P = 0.90), or HIV-related mortality (HR = 0.93, 95% CI: 0.46-1.87, P = 0.83).
Conclusion There was no immediate benefit of the Treat All strategy on mortality, nor evidence of harm. Longer follow-up of participants is needed to establish long-term consequences
Using detergent to enhance detection sensitivity of African trypanosomes in human CSF and blood by Loop-Mediated Isothermal Amplification (LAMP)
<p><b>Background:</b> The loop-mediated isothermal amplification (LAMP) assay, with its advantages of simplicity, rapidity and cost effectiveness, has evolved as one of the most sensitive and specific methods for the detection of a broad range of pathogenic microorganisms including African trypanosomes. While many LAMP-based assays are sufficiently sensitive to detect DNA well below the amount present in a single parasite, the detection limit of the assay is restricted by the number of parasites present in the volume of sample assayed; i.e. 1 per ”L or 103 per mL. We hypothesized that clinical sensitivities that mimic analytical limits based on parasite DNA could be approached or even obtained by simply adding detergent to the samples prior to LAMP assay.</p>
<p><b>Methodology/Principal Findings:</b> For proof of principle we used two different LAMP assays capable of detecting 0.1 fg genomic DNA (0.001 parasite). The assay was tested on dilution series of intact bloodstream form Trypanosoma brucei rhodesiense in human cerebrospinal fluid (CSF) or blood with or without the addition of the detergent Triton X-100 and 60 min incubation at ambient temperature. With human CSF and in the absence of detergent, the LAMP detection limit for live intact parasites using 1 ”L of CSF as the source of template was at best 103 parasites/mL. Remarkably, detergent enhanced LAMP assay reaches sensitivity about 100 to 1000-fold lower; i.e. 10 to 1 parasite/mL. Similar detergent-mediated increases in LAMP assay analytical sensitivity were also found using DNA extracted from filter paper cards containing blood pretreated with detergent before card spotting or blood samples spotted on detergent pretreated cards.</p>
<p><b>Conclusions/Significance:</b> This simple procedure for the enhanced detection of live African trypanosomes in biological fluids by LAMP paves the way for the adaptation of LAMP for the economical and sensitive diagnosis of other protozoan parasites and microorganisms that cause diseases that plague the developing world.</p>
A Viral Vectored Prime-Boost Immunization Regime Targeting the Malaria Pfs25 Antigen Induces Transmission-Blocking Activity
The ookinete surface protein Pfs25 is a macrogamete-to-ookinete/ookinete stage antigen of Plasmodium falciparum, capable of exerting high-level anti-malarial transmission-blocking activity following immunization with recombinant protein-in-adjuvant formulations. Here, this antigen was expressed in recombinant chimpanzee adenovirus 63 (ChAd63), human adenovirus serotype 5 (AdHu5) and modified vaccinia virus Ankara (MVA) viral vectored vaccines. Two immunizations were administered to mice in a heterologous prime-boost regime. Immunization of mice with AdHu5 Pfs25 at week 0 and MVA Pfs25 at week 10 (Ad-MVA Pfs25) resulted in high anti-Pfs25 IgG titers, consisting of predominantly isotypes IgG1 and IgG2a. A single priming immunization with ChAd63 Pfs25 was as effective as AdHu5 Pfs25 with respect to ELISA titers at 8 weeks post-immunization. Sera from Ad-MVA Pfs25 immunized mice inhibited the transmission of P. falciparum to the mosquito both ex vivo and in vivo. In a standard membrane-feeding assay using NF54 strain P. falciparum, oocyst intensity in Anopheles stephensi mosquitoes was significantly reduced in an IgG concentration-dependent manner when compared to control feeds (96% reduction of intensity, 78% reduction in prevalence at a 1 in 5 dilution of sera). In addition, an in vivo transmission-blocking effect was also demonstrated by direct feeding of immunized mice infected with Pfs25DR3, a chimeric P. berghei line expressing Pfs25 in place of endogenous Pbs25. In this assay the density of Pfs25DR3 oocysts was significantly reduced when mosquitoes were fed on vaccinated as compared to control mice (67% reduction of intensity, 28% reduction in prevalence) and specific IgG titer correlated with efficacy. These data confirm the utility of the adenovirus-MVA vaccine platform for the induction of antibodies with transmission-blocking activity, and support the continued development of this alternative approach to transmission-blocking malaria subunit vaccines
Plasmodium berghei Circumvents Immune Responses Induced by Merozoite Surface Protein 1- and Apical Membrane Antigen 1-Based Vaccines
BACKGROUND: Two current leading malaria blood-stage vaccine candidate antigens for Plasmodium falciparum, the C-terminal region of merozoite surface protein 1 (MSP1(19)) and apical membrane antigen 1 (AMA1), have been prioritized because of outstanding protective efficacies achieved in a rodent malaria Plasmodium yoelii model. However, P. falciparum vaccines based on these antigens have had disappointing outcomes in clinical trials. Discrepancies in the vaccine efficacies observed between the P. yoelii model and human clinical trials still remain problematic. METHODOLOGY AND RESULTS: In this study, we assessed the protective efficacies of a series of MSP1(19)- and AMA1-based vaccines using the P. berghei rodent malarial parasite and its transgenic models. Immunization of mice with a baculoviral-based vaccine (BBV) expressing P. falciparum MSP1(19) induced high titers of PfMSP1(19)-specific antibodies that strongly reacted with P. falciparum blood-stage parasites. However, no protection was achieved following lethal challenge with transgenic P. berghei expressing PfMSP1(19) in place of native PbMSP1(19). Similarly, neither P. berghei MSP1(19)- nor AMA1-BBV was effective against P. berghei. In contrast, immunization with P. yoelii MSP1(19)- and AMA1-BBVs provided 100% and 40% protection, respectively, against P. yoelii lethal challenge. Mice that naturally acquired sterile immunity against P. berghei became cross-resistant to P. yoelii, but not vice versa. CONCLUSION: This is the first study to address blood-stage vaccine efficacies using both P. berghei and P. yoelii models at the same time. P. berghei completely circumvents immune responses induced by MSP1(19)- and AMA1-based vaccines, suggesting that P. berghei possesses additional molecules and/or mechanisms that circumvent the host's immune responses to MSP1(19) and AMA1, which are lacking in P. yoelii. Although it is not known whether P. falciparum shares these escape mechanisms with P. berghei, P. berghei and its transgenic models may have potential as useful tools for identifying and evaluating new blood-stage vaccine candidate antigens for P. falciparum
Inhibition of 26S Protease Regulatory Subunit 7 (MSS1) Suppresses Neuroinflammation
Recently, researchers have focused on immunosuppression induced by rifampicin. Our previous investigation found that rifampicin was neuroprotective by inhibiting the production of pro-inflammatory mediators, thereby suppressing microglial activation. In this study, using 2-dimensional gel electrophoresis (2-DE) and mass spectrometry (MS), we discovered that 26S protease regulatory subunit 7 (MSS1) was decreased in rifampicin-treated microglia. Western blot analysis verified the downregulation of MSS1 expression by rifampicin. As it is indicated that the modulation of the ubiquitin-26S proteasome system (UPS) with proteasome inhibitors is efficacious for the treatment of neuro-inflammatory disorders, we next hypothesized that silencing MSS1 gene expression might inhibit microglial inflammation. Using RNA interference (RNAi), we showed significant reduction of IkBα degradation and NF-kB activation. The production of lipopolysaccharides-induced pro-inflammatory mediators such as inducible nitric oxide synthase (iNOS), nitric oxide, cyclooxygenase-2, and prostaglandin E2 were also reduced by MSS1 gene knockdown. Taken together, our findings suggested that rifampicin inhibited microglial inflammation by suppressing MSS1 protein production. Silencing MSS1 gene expression decreased neuroinflammation. We concluded that MSS1 inhibition, in addition to anti-inflammatory rifampicin, might represent a novel mechanism for the treatment of neuroinflammatory disorders
A Molecular Epidemiological and Genetic Diversity Study of Tuberculosis in Ibadan, Nnewi and Abuja, Nigeria
Background
Nigeria has the tenth highest burden of tuberculosis (TB) among the 22 TB high-burden countries in the world. This study describes the biodiversity and epidemiology of drug-susceptible and drug-resistant TB in Ibadan, Nnewi and Abuja, using 409 DNAs extracted from culture positive TB isolates.
Methodology/Principal Findings
DNAs extracted from clinical isolates of Mycobacterium tuberculosis complex were studied by spoligotyping and 24 VNTR typing. The Cameroon clade (CAM) was predominant followed by the M. africanum (West African 1) and T (mainly T2) clades. By using a smooth definition of clusters, 32 likely epi-linked clusters related to the Cameroon genotype family and 15 likely epi-linked clusters related to other âmodernâ genotypes were detected. Eight clusters concerned M. africanum West African 1. The recent transmission rate of TB was 38%. This large study shows that the recent transmission of TB in Nigeria is high, without major regional differences, with MDR-TB clusters. Improvement in the TB control programme is imperative to address the TB control problem in Nigeria
Economics of Technology Innovation for Sustainable Growth â With reference to Sub-Saharan Africa (SSA)
Innovation economics is geared towards harnessing the good in human ingenuity to bring about dynamic efficiency that result in changed habit formation of consumer choices in the market, together with high quality / performance of goods and services consumed by economic agents. In as much as the worries or concern that innovation bring, given its characteristics of creatively destroying existing ideas or product existence in the market, it can still be seen as the way forward in accumulating wealth creation, while increasing welfare opportunities for those who are ready to embrace change in a fiercely competitive environment. Figure 1 below provide a simple illustration of how cost-reducing innovation and technological change can be utilised to bring about positive gains in producer and consumer surplus (Riley, Online) which eventually result in lower prices, and the scope for an increase in real income of households or individuals
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