Academic Wits Research Outputs (All submissions)
Permanent URI for this collectionhttps://hdl.handle.net/10539/36827
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Item Tuberculosis preventive therapy : An underutilised strategy to reduce individual risk of TB and contribute to TB control(2014-05) Churchyard, G J; Chaisson, R E; Maartens, G; et al.Tuberculosis (TB) remains a global health problem, and South Africa (SA) has one of the world’s worst TB epidemics. The World Health Organization (WHO) estimated in 1999 that one-third of the world’s population was latently infected with TB. In SA up to 88% of HIV-uninfected young adults (31 - 35 years) are latently infected with TB. In the most recent meta-analysis, 6 - 12 months of isoniazid preventive therapy (IPT) was associated with a lower incidence of active TB than placebo (relative risk (RR) 0.68; 95% confidence interval (CI) 0.54 - 0.85), with the greatest benefit among individuals with a positive tuberculin skin test (TST) (RR 0.38; 95% CI 0.25 - 0.57). A clinical trial of IPT given with antiretroviral therapy (ART) for 12 months reduced TB incidence by 37% compared with ART alone (hazard ratio (HR) 0.63; 95% CI 0.41 - 0.94). The effect of IPT is limited in high-burden countries. IPT for 36 months v. 6 months reduced TB incidence among HIV-positive, TST-positive participants by 74% (HR 0.26; 95% CI 0.09 - 0.80). A study of more than 24 000 goldminers confirmed that IPT is safe, with only 0.5% experiencing adverse events. A meta-analysis of studies of IPT since 1951 did not show an increased risk of developing resistance. Alternative TB preventive therapy regimens, including high-dose isoniazid and rifapentine given weekly for 3 months, have been shown to have similar efficacy to IPT. Mathematical modelling suggests that scaling up continuous IPT targeted to HIV-positive persons, when used in combination with other treatment and prevention strategies, may substantially improve TB control.Item Tuberculosis control in South Africa : Successes challenges and recommendations(2014-03) Churchyard, G J; Mametja, L D; Mvusi, L; et al.Tuberculosis (TB) remains a global health threat, and South Africa (SA) has one of the world’s worst TB epidemics driven by HIV. Among the 22 countries with the highest burden of TB, SA has the highest estimated incidence and prevalence of TB, the second highest number of diagnosed multidrug-resistant TB cases, and the largest number of HIV-associated TB cases. Although SA has made notable progress in reducing TB prevalence and deaths and improving treatment outcomes for new smear-positive TB cases, the burden of TB remains enormous. SA has the means to overcome this situation. In addition to better implementing the basics of TB diagnosis and treatment,scaling up the use of Xpert MTB/RIF as a replacement for sputum smear microscopy, strengthening case finding in and beyond healthcare facilities and a greater focus on TB prevention for people living with HIV, particularly earlier initiation of and scaling up antiretroviral therapy and scaling up continuous isoniazid preventive therapy, will have a substantial impact on TB control. New TB drugs, diagnostics and vaccines are required to further accelerate progress towards improved TB control in SA and beyond