Browsing by Author "Machingaidze, Shingai"

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    Open Access
    The predictive value of a QuantiFERON conversion in the development of active tuberculosis disease in adolescents
    (2011) Machingaidze, Shingai; Mahomed, Hassan
    This study is an extension of a prospective epidemiological study of TB disease and infection in adolescents in the Worcester and surrounding areas in the Western Cape carried out from 2005 to 2009, in which 6363 participants were enrolled from local public schools. In this follow-on study, a subset of adolescents who were identified to have converted their QFT status during the original study will be followed up and observed for the occurrence of active TB disease over a period of two years. A similar sized, random sample of participants identified to have a QFT status that remained negative throughout the original study will be used as the control group.
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    Strengthening the expanded programme on immunization in Africa: looking beyond 2015
    (Public Library of Science, 2013) Machingaidze, Shingai; Wiysonge, Charles S; Hussey, Gregory D
    Shingai Machingaidze and colleagues reflect on the successes and shortfalls of the Expanded Programme on Immunization (EPI) in Africa, and the considerable challenges that must now be addressed to improve immunization systems.
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    Trends in the types and quality of childhood immunisations research output from Africa 1970–2010: mapping the evidence base
    (2014-02-04) Machingaidze, Shingai; Hussey, Gregory D; Wiysonge, Charles S
    Abstract Background Over the past four decades, extraordinary progress has been made in establishing and improving childhood immunization programmes around Africa. In order to ensure effective and sustainable positive growth of these childhood immunisations programmes, the development, adaptation and implementation of all interventions (programme activities, new vaccines, new strategies and policies) should be informed by the best available local evidence. Methods An assessment of the peer-reviewed literature on childhood immunization research published in English from 1970 to 2010 was conducted in PubMed and Africa-Wide databases. All study types were eligible for inclusion. A standard form was used to extract information from all studies identified as relevant and entered into a Microsoft Access database for analysis. Results Our initial search yielded 5436 articles from the two databases, from which 848 full text articles were identified as relevant. Among studies classified as clinical research (417), 40% were clinical trials, 24% were burden of disease/epidemiology and 36% were other clinical studies. Among studies classified as operational research (431), 77% related to programme management, 18% were policy related and 5% were related to vaccine financing. Studies were conducted in 48 African countries with six countries (South Africa, The Gambia, Nigeria, Senegal, Guinea-Bissau and Kenya) accounting for 56% of the total research output. Studies were published in 152 different journals with impact factors ranging from 0.192 to 53.29; with a median impact factor of 3.572. Conclusion A similar proportion of clinical versus operational research output was found. However, an uneven distribution across Africa was observed with only six countries accounting for over half of the research output. The research conducted was of moderate to high quality, with 62% being published in journals with 2010 impact factors greater than two. Urgent attention should be given to the development of research capacity in low performing countries around Africa, with increased focus on the process of turning immunisations programme research evidence into policy and practice, as well as increased focus on issues relating to vaccine financing and sustainability in Africa.
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    Understanding interventions for improving routine immunization coverage in children in low- and middle-income countries: a systematic review protocol
    (BioMed Central Ltd, 2013) Machingaidze, Shingai; Rehfuess, Eva; von Kries, Rudiger; Hussey, Gregory; Wiysonge, Charles
    BACKGROUND: Virtually all low- and middle-income countries are dependent on the World Health Organization's Expanded Program on Immunization for delivery of vaccines to children. The Expanded Program on Immunization delivers routine immunization services from health facilities free of charge. Understanding interventions for improving immunization coverage remains key in achieving universal childhood immunization. METHODS: We will conduct a systematic review that aims to assess the effectiveness of the full range of potential interventions to improve routine immunization coverage in children in low- and middle-income countries. We will include intervention studies, as well as observational studies. We will search the Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, electronic databases for eligible studies published by 31 August 2013. At least two authors will independently screen search outputs, select studies, extract data and assess the risk of bias (using separate criteria for interventions and observational studies); resolving any disagreements by discussion and consensus. The use of logic models and the Cochrane Complexity Matrix will be explored in order to better understand and contextualize studies. We will express the result of each study as a risk ratio with its corresponding 95% confidence intervals for dichotomous data, or mean difference with its standard deviation for continuous data. We will conduct meta-analysis for the same type of participants, interventions, study designs, and outcome measures where homogeneity of data allows. Use of harvest plots may be explored as an alternative. Heterogeneity will be assessed using the chi2 test of heterogeneity, and quantified using the I2 statistic. This protocol has not been registered with PROSPERO.DISCUSSION:This review will allow us to document evidence across a broad range of intervention types for improving routine immunization coverage in children and also distinguish between those that are well supported by evidence (to direct policy recommendations) and those that are not well supported (to direct research agenda).