30 research outputs found

    EXTERNAL QUALITY ASSURANCE (EQA) A PIVOT OF LABORATORY MEDICINE.

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    The role and implications of RNAscope and mRNA in the diagnosis of tuberculosis

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    Funding: The authors’ research on host biomarkers of TB diagnosis is supported by the Wellcome Trust Institutional Strategic Support fund of the University of St Andrews, grant code 204821/Z/16/Z.Peer reviewe

    Improved sanitation training

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    In Uganda, technical personnel in the Sanitation Sector experience challenges that are not adequately catered for in their training. The situation is aggravated by the fact that the training syllabi is adopted from the colonial times and does not in many cases cater for the local conditions. For the efficient functioning and service delivery in the sanitation sector it is important that technical personnel are adequately trained to handle challenges in the field. The available training options and some of the challenges faced are discussed and proposed recommendations made. Through interviewing some of the technical personnel in the sector, it was reported that some aspects of the training were inadequate and there was need for improvement. It is recommended that training of the technical personnel is updated to suit the prevailing needs and appropriate methodologies of training should be used. This would contribute to improvement in the delivery of services in the Sanitation Sector

    Cytoadherence in paediatric malaria: ABO blood group, CD36, and ICAM1 expression and severe Plasmodium falciparum infection

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    As a leading cause of childhood mortality worldwide, selection pressure by Plasmodium falciparum continues to shape the human genome. Severe disturbances within the microcirculation result from the adhesion of infected erythrocytes to host receptors on monocytes, platelets, and endothelium. In this prospective study, we compared expression of all major host cytoadhesion receptors among Ugandan children presenting with uncomplicated malaria (n = 1078) versus children with severe malaria (n = 855), including cerebral malaria (n = 174), severe anaemia (n = 522), and lactic acidosis (n = 154). We report a significant survival advantage attributed to blood group O and increased monocyte expression of CD36 and ICAM1 (CD54). The high case fatality rate syndromes of cerebral malaria and lactic acidosis were associated with high platelet CD36 expression and thrombocytopenia, and severe malaria anaemia was characterized by low ICAM1 expression. In a logistic regression model of disease severity, odds ratios for the mitigating effects of blood group O, CD36, and ICAM1 phenotypes were greater than that of sickle haemoglobin. Host genetic adaptations to Plasmodium falciparum suggest new potential malaria treatment strategies

    Inter-Relationships of Cardinal Features and Outcomes of Symptomatic Pediatric Plasmodium falciparum Malaria in 1,933 Children in Kampala, Uganda

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    Malaria remains a challenging diagnosis with variable clinical presentation and a wide spectrum of disease severity. Using a structured case report form, we prospectively assessed 1,933 children at Mulago Hospital in Kampala, Uganda with acute Plasmodium falciparum malaria. Children with uncomplicated malaria significantly differed from those with severe disease for 17 features. Among 855 children with severe disease, the case-fatality rate increased as the number of severity features increased. Logistic regression identified five factors independently associated with death: cerebral malaria, hypoxia, severe thrombocytopenia, leukocytosis, and lactic acidosis. Cluster analysis identified two groups: one combining anemia, splenomegaly, and leukocytosis; and a second group centered on death, severe thrombocytopenia, and lactic acidosis, which included cerebral malaria, hypoxia, hypoglycemia, and hyper-parasitemia. Our report updates previous clinical descriptions of severe malaria, quantifies significant clinical and laboratory inter-relationships, and will assist clinicians treating malaria and those planning or assessing future research (NCT00707200) (www.clinicaltrials.gov)

    Frequencies of Gag-restricted T-cell escape "footprints" differ across HIV-1 clades A1 and D chronically infected Ugandans irrespective of host HLA B alleles.

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    OBJECTIVE(S): We evaluated relationships between critical Gag T-cell escape mutations and concomitant T-cell responses to determine whether HLA-restricted Gag mutations that confer protection, occur at similar rates in a population infected with mixed HIV-1 clades A1 and D viruses. METHODS: Assessment of Gag selective pressure, and adaptive T-cell functions to KAFSPEVIPMF (KF11), ISPRTLNAW (ISW9) and TSTLQEQIGW (TW10) Gag epitopes were combined with host HLA to assess correlations with rates of critical epitope escape mutations in clades A1- (n=23) and D- (n=21) infected, untreated subjects. Infecting clades and selection pressure were determined from the gag sequences. RESULTS: Overall, Gag escape mutations A163X in KF11 were detected in 61% (14/23) A1- infected compared to 5% (1/21) in D-infected subjects (p=0.00015). Gag mutations I147X in the ISW9 epitope were seen in 43%: (10/23) clade A compared to 5%: (1/21) clade D infected subjects, p=0.007, Fisher's Exact test. Both mutations were more frequent in clade A1 infection. Frequencies of the measured epitope-specific T-cell responses were comparable across clades. Peptide binding affinities for the restricting HLA alleles did not differ across clades. Overall, selection pressure on the Gag protein was significantly greater in clade A than in clade D sequences. CONCLUSIONS: These findings imply that HIV-1 vaccine strategies designed to target structurally constrained T-cell epitopes may be further challenged by clade-driven outcomes in specific HLA-restricted Gag epitopes. Equally, the data are line with slower HIV-1 disease progression in clade A infection; and raise hope that increased selective pressure on Gag may be protective irrespective of host HLA alleles

    Interferon gamma (IFN-γ) negative CD4+ and CD8+ T-cells can produce immune mediators in response to viral antigens.

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    Evaluation of antigen-specific T-cell responses to viral antigens is frequently performed on IFN-γ secreting cells. However, T-cells are capable of producing many more functions than just IFN-γ, some of which, like Perforin, are associated with immune protection in HIV-1 disease elite controllers. We evaluated the extent of missed T-cell functions when IFN-γ secretion is used as a surrogate marker for further evaluation of T-cell functions. Intracellular cytokine staining assay and flow cytometry were used to assess peripheral blood mononuclear cells (PBMCs) from 31 HIV-infected ART-naive individuals for the extent to which gated CD4+ and CD8+ IFN-γ producing and non-producing T-cells also secreted IL-2, Perforin, and TNF-α functions. Similarly, the extent of missed virus-specific responses in IFN-γ ELISpot assay negative T-cells from 5 HIV-1 uninfected individuals was evaluated. Cells from HIV-infected individuals were stimulated with pooled consensus group M (Con M) peptides; and those from healthy individuals were stimulated with pooled adenovirus (Ad) peptides. Overall, frequencies of virus-specific IFN-γ secreting CD4+ and CD8+ cells were low. Proportions of IFN-γ negative CD4+ expressing IL-2, Perforin, or TNF-α to Con M were significantly higher (5 of 7 functional profiles) than the corresponding IFN-γ positive CD4+ (0 of 7) T-cell phenotype, p = 0.02; Fisher's Exact test. Likewise, proportions of CD8+ T-cells expressing other functions were significantly higher in 4 of the 7 IFN-γ negative CD8+ T-cells. Notably, newly stimulated Perforin, identified as Perforin co-expression with IL-2 or TNF-α, was significantly higher in IFN-γ negative CD8+ T-cell than in the positive CD8+ T-cells. Using SEB, lower responses in IFN-γ positive cells were most associated with CD4+ than CD8+ T-cells. These findings suggest that studies evaluating immunogenicity in response to HIV and Adenovirus viral antigens should not only evaluate T-cell responsiveness among IFN-γ producing cells but also among those T-cells that do not express IFN-γ

    Presumptive treatment with sulphadoxine-pyrimethamine versus weekly chloroquine for malaria prophylaxis in children with sickle cell anaemia in Uganda: a randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Malaria carries high case fatality among children with sickle cell anaemia. In Uganda, chloroquine is used for prophylaxis in these children despite unacceptably high levels of resistance. Intermittent presumptive treatment with sulphadoxine-pyrimethamine (SP) has shown great potential for reducing prevalence of malaria and anaemia among pregnant women and infants.</p> <p>Objective</p> <p>To compare the efficacy of monthly SP presumptive treatment, versus weekly chloroquine for malaria prophylaxis in children attending the Sickle Cell Clinic, Mulago Hospital.</p> <p>Methods</p> <p>Two hundred and forty two children with sickle cell anaemia were randomized to presumptive treatment with SP or weekly chloroquine for malaria prophylaxis. Active detection of malaria was made at each weekly visit to the clinic over one month. The primary outcome measure was the proportion of children with one malaria episode at one month follow-up. The secondary outcome measures included malaria-related admissions and adverse effects of the drugs.</p> <p>Results</p> <p>Ninety-three percent (114/122) of the children in the chloroquine group and 94% (113/120) in the SP group completed one month follow up. SP reduced prevalence of malaria by 50% compared to chloroquine [OR = 0.50, (95% CI 0.26-0.97)]; p = 0.042. Six percent (7/122) of the children receiving weekly chloroquine had malaria related admissions compared to 2.5% (3/120) on presumptive treatment with SP. No serious drug effects were reported in both treatment groups</p> <p>Conclusion</p> <p>Presumptive treatment with SP was more efficacious than weekly chloroquine in reducing prevalence of malaria in children with sickle cell anaemia. Continued use of chloroquine for malaria chemoprophylaxis in children with sickle cell anaemia in Uganda does not seem to be justified.</p> <p>Clinical Trials Registration</p> <p>ClinicalTrials.gov Identifier: NCTOO124267</p

    Long-Term Outcomes of the Good School Toolkit Primary School Violence Prevention Intervention Among Adolescents: Protocol for a Nonrandomized Quasi-Experimental Study.

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    BACKGROUND: Violence against children in schools is a global public health problem. There is growing evidence that school-based interventions can be effective in reducing violence against children in schools. However, there is little evidence on the long-term impact of such interventions. The Good School Toolkit, developed by Raising Voices, a Uganda-based nonprofit organization, is a whole-school violence prevention intervention that aims to change the operational culture of primary schools. In 2014, the Good School Toolkit was evaluated through a cluster randomized controlled trial (Good Schools Study) and found to reduce teacher-to-student and student-to-student violence. OBJECTIVE: This protocol describes quantitative analyses to explore long-term outcomes of the Good School Toolkit intervention among adolescents in Uganda, including the extent to which it is associated with peer-violence victimization (primary outcome) and peer-violence perpetration, intimate-partner violence, acceptance of teacher-violence, equitable gender attitudes, agency, self-regulation, peer connectedness, social assets, psychological assets, and retention in school (secondary outcomes). METHODS: This is a nonrandomized quasi-experimental 4-year follow-up study of adolescents who attended the 42 Good Schools Study primary schools in 2014; 21 schools initiated the Good School Toolkit intervention during the trial from 2012, and 19 schools initiated the intervention after the trial (during the later delivery phase) from 2015; 2 schools did not implement the intervention. Students in the final school grade (Primary 7) during 2014 of the 19 primary schools in the later delivery phase are expected to have left school prior to toolkit delivery in 2015. Wave 1 data were collected in 2014 from 3431 grade Primary 5 to Primary 7 school students aged 11-14 years; these students were followed up in 2018-2019 when aged 16-19 years and invited to participate in the Wave 2 survey. Data were collected in face-to-face interviews by trained Ugandan field researchers. Toolkit exposure groups are defined as exposed during the Good Schools Study trial (from 2012), as exposed during later delivery (from 2015), or not exposed including those expected to have completed Primary 7 prior to later delivery or from the 2 schools that did not implement the toolkit. Associations between outcomes at Wave 2 and toolkit exposure groups will be analyzed using mixed-effect multivariable logistic and linear regression models for binary and continuous outcomes, respectively. This analysis is exploratory and aims to generate hypotheses on if, and under what circumstances, the toolkit influences later adolescent outcomes. RESULTS: Data collection was completed in August 2019. CONCLUSIONS: To our knowledge, this is the first long-term follow-up study of adolescents exposed to a school-based violence-prevention intervention in sub-Saharan Africa. If the intervention reduces violence and improves other outcomes in later adolescence, then this study supports primary school interventions as key to achieving long-term population impacts. The pattern of effects will inform where reinforced or additional interventions are needed. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/20940
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