Browsing by Subject "drug resistance"

Now showing 1 - 6 of 6
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    Open Access
    Conceptualising the right to enjoy benefits of scientific progress and exploring its potential to enhance access to effective diagnosis and treatment of drug-resistant tuberculosis in South Africa
    (2019) Shawa, Remmy Malama; London, Leslie; Coomans, Fons; Cox, Helen
    The lack of access to effective diagnosis and treatment of drug-resistant tuberculosis (DR-TB) remains a persistent global challenge. Human rights arguments for access to treatment mostly focus on the right to health. However, a key challenge in access to effective diagnosis and treatment is the glaring absence of scientific research in neglected diseases such as TB. This thesis sets out to elaborate the right to enjoy the benefits of scientific progress and explore its potential to increase scientific research in DR-TB and consequently enhance access to effective diagnosis and treatment in South Africa. This research project was conducted using three interrelated sub-studies; a legal analysis sub-study which examines the current conceptualisation of the REBSP in international law; a policy analysis sub-study which interrogates South Africa’s legal and policy efforts towards the realisation of the REBSP and access to diagnosis and treatment for DR-TB; and a qualitative sub-study which explores the South African context regarding research and development (R&D) in general, and in DR-TB in particular. The qualitative sub-study included 17 stakeholders who are active in TB R&D, advocacy and policy work, from human rights and research institutions, government agencies, civil society organisations, and donor agencies. This thesis finds that the REBSP essentially ensures two things, namely the production of science and access to the benefits of scientific progress. However, most countries including South Africa have systems, policies and resources aimed at advancing the production of science but lack similar systems, policies and resources to purposely ensure the enjoyment of the benefits from scientific progress. Internationally, there is no clear guidance on the interpretation of the REBSP, making it difficult for states to domesticate it in their national policies and framework laws. A General Comment by a UN human rights monitoring body is therefore urgently needed to secure global consensus on the interpretation of the REBSP. In the meanwhile, South Africa can still draw inspiration for the REBSP and together with the right to health, use it to advance access to DR-TB diagnosis and treatment alongside many other interventions. To enable better access to effective diagnosis and treatment of DR-TB, this thesis recommends that South Africa i) develops systems that would make scientific progress and results accessible, and affordable; ii) removes system and regulatory barriers that hinder the conduct of research or that delay registration of new drugs; iii) monitors and regulates the conduct of third parties and prevent them from exploiting communities; iv) encourages pharmaceutical companies to provide free access to successful treatment and tools in communities where trials are conducted; and v) mobilises financial and technical resources and allocates them to DR-TB researchfrom drug discovery through to implementation science.
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    Extensively drug-resistant tuberculosis in Africa: prevalence and factors associated: a systematic review and meta-analysis
    (2019) Kosmas, Petrus Ndiiluka; Ncayiyana, Jabulani; Engel, Mark E.
    Background: There is a dearth of information regarding prevalence of extensively drugresistant tuberculosis (XDR-TB) in Africa. Although countries in Africa conduct national tuberculosis surveys on a regular basis, this information has not been systematically reviewed to ascertain the overall prevalence of XDR-TB in Africa. Methods: The study aimed to perform a systematic review and meta-analysis of the prevalence and factors associated with prevalence of pulmonary XDR-TB among adults in Africa. Eligible studies, published between 2006 and 2018, were sourced from various electronic databases including PubMed, Scopus, and Web of Science. Meta-analysis was performed using STATA (version 14.2) statistical software. The protocol of this review was registered with PROSPERO, reg No CRD42018117037. Result: A total of 6242 records were retrieved. Forty-eight studies were screened for eligibility and seven, which varied in terms of country setting and study design, were included. The prevalence of XDR-TB is 4% (95%CI 2-7) among participants tested for second-line anti-TB drug resistance, and 3% (95%1-6) among participants with drug resistant TB. The prevalence of XDR-TB was 7% (95%CI 1-18) among participants with MDR-TB. A few studies reported on the factors associated with the prevalence of XDR-TB. Discussion: The reported prevalence of XDR-TB among participants tested for second-line anti-TB drug resistance is low compared to WHO estimates. The systematic review underscores a dearth of studies depicting the reality regarding the prevalence of XDR-TB in Africa. Policymakers and stakeholders interested in drug-resistant TB should apply prudence when considering XDR-TB prevalence reported for Africa.
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    The road to drug resistance in Mycobacterium tuberculosis
    (BioMed Central Ltd, 2014) Koch, Anastasia; Wilkinson, Robert
    Sequencing of serial isolates of extensively drug-resistant tuberculosis highlights how drug resistance develops within a single patient and reveals unexpected levels of pathogen diversity.
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    The within-host population dynamics of Mycobacterium tuberculosis vary with treatment efficacy
    (2017) Trauner, Andrej; Liu, Qingyun; Via, Laura E; Liu, Xin; Ruan, Xianglin; Liang, Lili; Shi, Huimin; Chen, Ying; Wang, Ziling; Liang, Ruixia; Zhang, Wei; Wei, Wang; Gao, Jingcai; Sun, Gang; Brites, Daniela; England, Kathleen; Zhang, Guolong; Gagneux, Sébastien; Barry, Clifton E; Gao, Qian
    BACKGROUND: Combination therapy is one of the most effective tools for limiting the emergence of drug resistance in pathogens. Despite the widespread adoption of combination therapy across diseases, drug resistance rates continue to rise, leading to failing treatment regimens. The mechanisms underlying treatment failure are well studied, but the processes governing successful combination therapy are poorly understood. We address this question by studying the population dynamics of Mycobacterium tuberculosis within tuberculosis patients undergoing treatment with different combinations of antibiotics. RESULTS: By combining very deep whole genome sequencing (~1000-fold genome-wide coverage) with sequential sputum sampling, we were able to detect transient genetic diversity driven by the apparently continuous turnover of minor alleles, which could serve as the source of drug-resistant bacteria. However, we report that treatment efficacy has a clear impact on the population dynamics: sufficient drug pressure bears a clear signature of purifying selection leading to apparent genetic stability. In contrast, M. tuberculosis populations subject to less drug pressure show markedly different dynamics, including cases of acquisition of additional drug resistance. CONCLUSIONS: Our findings show that for a pathogen like M. tuberculosis, which is well adapted to the human host, purifying selection constrains the evolutionary trajectory to resistance in effectively treated individuals. Nonetheless, we also report a continuous turnover of minor variants, which could give rise to the emergence of drug resistance in cases of drug pressure weakening. Monitoring bacterial population dynamics could therefore provide an informative metric for assessing the efficacy of novel drug combinations.
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    Treatment Failure and Adherence in Second- Line Patients
    (2012-10) Barnett, Whitney
    Results from an interview and photo-based research study looking at barriers and facilitators to adherence for second-line patients.
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    Why patients struggle with anti-retroviral treatment
    (2012-10) UCT Knowledge Co-op
    This is a Public Health project. The recent increase of anti-retroviral treatment (ART) in public clinics in South Africa means that many more people have access to treatment. If patients become resistant to the standard ART package they are put on an alternative second-line ART; if that fails, there is no further public treatment option to control the HI virus. Yet, literature addressing facilitators and barriers to treatment adherence faced by patients on second-line ART is scarce.