Giuseppe
Emeritus
Antiretroviral therapy for tuberculosis control in nine African countries (PNAS, abstract, edited)
[Source: Proc Natl Acad Sci USA, full text: <cite cite="http://www.pnas.org/content/107/45/19485.short?rss=1">Antiretroviral therapy for tuberculosis control in nine African countries ? PNAS</cite>. Abstract, edited.]
Antiretroviral therapy for tuberculosis control in nine African countries
1. Brian G. Williams a,1, 2. Reuben Granich b, 3. Kevin M. De Cock b, 4. Philippe Glaziou b, 5. Abhishek Sharma c, and 6. Christopher Dye b
Author Affiliations
1. (a) South African Centre for Epidemiological Modelling and Analysis, Stellenbosch 7600, South Africa;
2. (b) World Health Organization, 1211 Geneva, Switzerland; and
3. (c) Department of Public Health, University of Oxford, Oxford OX3 7LF, United Kingdom
1. Edited by Simon A. Levin, Princeton University, Princeton, NJ, and approved September 28, 2010 (received for review April 29, 2010)
Abstract
HIV has increased the incidence of tuberculosis (TB) by up to sevenfold in African countries, but antiretroviral therapy (ART) reduces the incidence of AIDS-related TB. We use a mathematical model to investigate the short-term and long-term impacts of ART on the incidence of TB, assuming that people are tested for HIV once a year, on average, and start ART at a fixed time after HIV seroconversion or at a fixed CD4+ cell count. We fit the model to trend data on HIV prevalence and TB incidence in nine countries in sub-Saharan Africa. If HIV-positive people start ART within 5 y of seroconversion, the incidence of AIDS-related TB in 2015 will be reduced by 48% (range: 37?55%). Long-term reductions depend sensitively on the delay to starting ART. If treatment is started 5, 2, or 1 y after HIV seroconversion, or as soon as people test positive, the incidence in 2050 will be reduced by 66% (range: 57?80%), 95% (range: 93?96%), 97.7% (range: 96.9?98.2%) and 98.4% (range: 97.8?98.9%), respectively. In the countries considered here, early ART could avert 0.71 ? 0.36 [95% confidence interval (CI)] million of 3.4 million cases of TB between 2010 and 2015 and 5.8 ? 2.9 (95% CI) million of 15 million cases between 2015 and 2050. As more countries provide ART at higher CD4+ cell counts, the impact on TB should be investigated to test the predictions of this model.
* Africa
* HIV
* test-and-treat
Footnotes
* 1 To whom correspondence should be addressed. E-mail: briangerardwilliams@gmail.com.
* Author contributions: B.G.W., R.G., K.M.D.C., P.G., and C.D. designed research; B.G.W. and C.D. performed research; B.G.W., P.G., A.S., and C.D. analyzed data; and B.G.W., R.G., K.M.D.C., P.G., and C.D. wrote the paper.
* The authors declare no conflict of interest.
* This article is a PNAS Direct Submission.
* This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1005660107/-/DCSupplemental.
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[Source: Proc Natl Acad Sci USA, full text: <cite cite="http://www.pnas.org/content/107/45/19485.short?rss=1">Antiretroviral therapy for tuberculosis control in nine African countries ? PNAS</cite>. Abstract, edited.]
Antiretroviral therapy for tuberculosis control in nine African countries
1. Brian G. Williams a,1, 2. Reuben Granich b, 3. Kevin M. De Cock b, 4. Philippe Glaziou b, 5. Abhishek Sharma c, and 6. Christopher Dye b
Author Affiliations
1. (a) South African Centre for Epidemiological Modelling and Analysis, Stellenbosch 7600, South Africa;
2. (b) World Health Organization, 1211 Geneva, Switzerland; and
3. (c) Department of Public Health, University of Oxford, Oxford OX3 7LF, United Kingdom
1. Edited by Simon A. Levin, Princeton University, Princeton, NJ, and approved September 28, 2010 (received for review April 29, 2010)
Abstract
HIV has increased the incidence of tuberculosis (TB) by up to sevenfold in African countries, but antiretroviral therapy (ART) reduces the incidence of AIDS-related TB. We use a mathematical model to investigate the short-term and long-term impacts of ART on the incidence of TB, assuming that people are tested for HIV once a year, on average, and start ART at a fixed time after HIV seroconversion or at a fixed CD4+ cell count. We fit the model to trend data on HIV prevalence and TB incidence in nine countries in sub-Saharan Africa. If HIV-positive people start ART within 5 y of seroconversion, the incidence of AIDS-related TB in 2015 will be reduced by 48% (range: 37?55%). Long-term reductions depend sensitively on the delay to starting ART. If treatment is started 5, 2, or 1 y after HIV seroconversion, or as soon as people test positive, the incidence in 2050 will be reduced by 66% (range: 57?80%), 95% (range: 93?96%), 97.7% (range: 96.9?98.2%) and 98.4% (range: 97.8?98.9%), respectively. In the countries considered here, early ART could avert 0.71 ? 0.36 [95% confidence interval (CI)] million of 3.4 million cases of TB between 2010 and 2015 and 5.8 ? 2.9 (95% CI) million of 15 million cases between 2015 and 2050. As more countries provide ART at higher CD4+ cell counts, the impact on TB should be investigated to test the predictions of this model.
* Africa
* HIV
* test-and-treat
Footnotes
* 1 To whom correspondence should be addressed. E-mail: briangerardwilliams@gmail.com.
* Author contributions: B.G.W., R.G., K.M.D.C., P.G., and C.D. designed research; B.G.W. and C.D. performed research; B.G.W., P.G., A.S., and C.D. analyzed data; and B.G.W., R.G., K.M.D.C., P.G., and C.D. wrote the paper.
* The authors declare no conflict of interest.
* This article is a PNAS Direct Submission.
* This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10.1073/pnas.1005660107/-/DCSupplemental.
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