Limits...
Tuberculosis control in South African gold mines: mathematical modeling of a trial of community-wide isoniazid preventive therapy.

Vynnycky E, Sumner T, Fielding KL, Lewis JJ, Cox AP, Hayes RJ, Corbett EL, Churchyard GJ, Grant AD, White RG - Am. J. Epidemiol. (2015)

Bottom Line: A recent major cluster randomized trial of screening, active disease treatment, and mass isoniazid preventive therapy for 9 months during 2006-2011 among South African gold miners showed reduced individual-level tuberculosis incidence but no detectable population-level impact.We found the following: 1) The model suggests that a small proportion of latent infections among human immunodeficiency virus-positive people were cured, which could have been a key factor explaining the lack of detectable population-level impact. 2) The optimized implementation increased impact by only 10%. 3) Implementing additional interventions individually and in combination led to up to 30% and 75% reductions, respectively, in tuberculosis incidence after 10 years.Tuberculosis control requires a combination prevention approach, including health systems strengthening to minimize treatment delay, improving diagnostics, increased antiretroviral treatment coverage, and effective preventive treatment regimens.

View Article: PubMed Central - PubMed

Show MeSH

Related in: MedlinePlus

Some of the key data used to parameterize the model describing the Thibela TB randomized controlled trial among South African gold miners, 2006–2011. A) Proportion of miners in the baseline and final prevalence surveys that reported ever taking ART; B) proportion of smear-positive and smear-negative miners who had not started TB treatment at different times since detection, according to mining company; C) monthly rates of in- and out-migration. Bars (in part A), 95% confidence interval. ART, antiretroviral therapy; TB, tuberculosis.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4388015&req=5

KWU320F3: Some of the key data used to parameterize the model describing the Thibela TB randomized controlled trial among South African gold miners, 2006–2011. A) Proportion of miners in the baseline and final prevalence surveys that reported ever taking ART; B) proportion of smear-positive and smear-negative miners who had not started TB treatment at different times since detection, according to mining company; C) monthly rates of in- and out-migration. Bars (in part A), 95% confidence interval. ART, antiretroviral therapy; TB, tuberculosis.

Mentions: Multiple competing hypotheses exist for why the trial detected no population-level impact, including suboptimal IPT uptake and/or retention or high population mobility (5). To robustly explore this question, we included in the model all known factors (age, HIV, silicosis, ART, in- and out-migration, case detection, initial loss to follow-up after detection, treatment delay, IPT uptake, and retention), at levels supported by detailed data collected during the study or by mine health services (Figure 3; Web Figure 1 (available at http://aje.oxfordjournals.org/)). Parameters (Table 1) were also drawn from publications or estimated by fitting model predictions to trial outcomes. Web Appendixes 1 and 2, Web Tables 1–7, and Web Figures 1–7 provide further details, including the model equations.Table 1.


Tuberculosis control in South African gold mines: mathematical modeling of a trial of community-wide isoniazid preventive therapy.

Vynnycky E, Sumner T, Fielding KL, Lewis JJ, Cox AP, Hayes RJ, Corbett EL, Churchyard GJ, Grant AD, White RG - Am. J. Epidemiol. (2015)

Some of the key data used to parameterize the model describing the Thibela TB randomized controlled trial among South African gold miners, 2006–2011. A) Proportion of miners in the baseline and final prevalence surveys that reported ever taking ART; B) proportion of smear-positive and smear-negative miners who had not started TB treatment at different times since detection, according to mining company; C) monthly rates of in- and out-migration. Bars (in part A), 95% confidence interval. ART, antiretroviral therapy; TB, tuberculosis.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4388015&req=5

KWU320F3: Some of the key data used to parameterize the model describing the Thibela TB randomized controlled trial among South African gold miners, 2006–2011. A) Proportion of miners in the baseline and final prevalence surveys that reported ever taking ART; B) proportion of smear-positive and smear-negative miners who had not started TB treatment at different times since detection, according to mining company; C) monthly rates of in- and out-migration. Bars (in part A), 95% confidence interval. ART, antiretroviral therapy; TB, tuberculosis.
Mentions: Multiple competing hypotheses exist for why the trial detected no population-level impact, including suboptimal IPT uptake and/or retention or high population mobility (5). To robustly explore this question, we included in the model all known factors (age, HIV, silicosis, ART, in- and out-migration, case detection, initial loss to follow-up after detection, treatment delay, IPT uptake, and retention), at levels supported by detailed data collected during the study or by mine health services (Figure 3; Web Figure 1 (available at http://aje.oxfordjournals.org/)). Parameters (Table 1) were also drawn from publications or estimated by fitting model predictions to trial outcomes. Web Appendixes 1 and 2, Web Tables 1–7, and Web Figures 1–7 provide further details, including the model equations.Table 1.

Bottom Line: A recent major cluster randomized trial of screening, active disease treatment, and mass isoniazid preventive therapy for 9 months during 2006-2011 among South African gold miners showed reduced individual-level tuberculosis incidence but no detectable population-level impact.We found the following: 1) The model suggests that a small proportion of latent infections among human immunodeficiency virus-positive people were cured, which could have been a key factor explaining the lack of detectable population-level impact. 2) The optimized implementation increased impact by only 10%. 3) Implementing additional interventions individually and in combination led to up to 30% and 75% reductions, respectively, in tuberculosis incidence after 10 years.Tuberculosis control requires a combination prevention approach, including health systems strengthening to minimize treatment delay, improving diagnostics, increased antiretroviral treatment coverage, and effective preventive treatment regimens.

View Article: PubMed Central - PubMed

Show MeSH
Related in: MedlinePlus