CD4 decline and incidence of opportunistic infections in Cape Town, South Africa: implications for prophylaxis and treatment.
ABSTRACT To determine the rate of CD4 decline and the incidence of opportunistic infections (OIs) among antiretroviral therapy-naive South African HIV-infected patients and inform timing of OI prophylaxis.
We used mixed-effect models to estimate CD4 cell decline by CD4 cell count strata in HIV-infected patients in the Cape Town AIDS Cohort between 1984 and 2000. Stratum-specific OI incidence per 100 person-years of observation was determined using incidence density analysis.
Nine hundred seventy-four patients with 2 or more CD4 cell counts were included. CD4 counts declined by 47.1 cells/microL per year in the stratum with more than 500 cells/microL stratum, 30.6 cells/microL per year in the stratum with 351 to 500 cells/microL, and 20.5 cells/microL per year in the stratum with 201 to 350 cells/microL. Tuberculosis and oral candidiasis were the only OIs that occurred frequently in the stratum with more than 200 CD4 cells/microL. Rates of chronic diarrhea, wasting syndrome, tuberculosis, and oral and esophageal candidiasis increased in the stratum with less than 200 cells/microL, and rates of all OIs were highest in the stratum with 50 cells/microL or less.
: CD4 cell count declines were dependent on CD4 strata and can inform timing of clinic visits and treatment initiation in South Africa. Incidence rates of OIs suggest that targeted OI prophylaxis could prevent substantial HIV-related morbidity in South Africa.
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ABSTRACT: The cost-effectiveness of early antiretroviral therapy (ART) in persons infected with human immunodeficiency virus (HIV) in serodiscordant couples is not known. Using a computer simulation of the progression of HIV infection and data from the HIV Prevention Trials Network 052 study, we projected the cost-effectiveness of early ART for such persons. For HIV-infected partners in serodiscordant couples in South Africa and India, we compared the early initiation of ART with delayed ART. Five-year and lifetime outcomes included cumulative HIV transmissions, life-years, costs, and cost-effectiveness. We classified early ART as very cost-effective if its incremental cost-effectiveness ratio was less than the annual per capita gross domestic product (GDP; $8,100 in South Africa and $1,500 in India), as cost-effective if the ratio was less than three times the GDP, and as cost-saving if it resulted in a decrease in total costs and an increase in life-years, as compared with delayed ART. In South Africa, early ART prevented opportunistic diseases and was cost-saving over a 5-year period; over a lifetime, it was very cost-effective ($590 per life-year saved). In India, early ART was cost-effective ($1,800 per life-year saved) over a 5-year period and very cost-effective ($530 per life-year saved) over a lifetime. In both countries, early ART prevented HIV transmission over short periods, but longer survival attenuated this effect; the main driver of life-years saved was a clinical benefit for treated patients. Early ART remained very cost-effective over a lifetime under most modeled assumptions in the two countries. In South Africa, early ART was cost-saving over a 5-year period. In both South Africa and India, early ART was projected to be very cost-effective over a lifetime. With individual, public health, and economic benefits, there is a compelling case for early ART for serodiscordant couples in resource-limited settings. (Funded by the National Institute of Allergy and Infectious Diseases and others.).New England Journal of Medicine 10/2013; 369(18):1715-25. · 51.66 Impact Factor
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ABSTRACT: Background. We sought to quantify the survival benefits attributable to antiretroviral therapy (ART) in South Africa since 2004.Methods. We used the Cost-Effectiveness of Preventing AIDS Complications-International model (CEPAC) to simulate 8 cohorts of human immunodeficiency virus (HIV)-infected patients initiating ART each year during 2004-2011. Model inputs included cohort-specific mean CD4(+) T-cell count at ART initiation (112-178 cells/µL), 24-week ART suppressive efficacy (78%), second-line ART availability (2.4% of ART recipients), and cohort-specific 36-month retention rate (55%-71%). CEPAC simulated survival twice for each cohort, once with and once without ART. The sum of the products of per capita survival differences and the total numbers of persons initiating ART for each cohort yielded the total survival benefits.Results. Lifetime per capita survival benefits ranged from 9.3 to 10.2 life-years across the 8 cohorts. Total estimated population lifetime survival benefit for all persons starting ART during 2004-2011 was 21.7 million life-years, of which 2.8 million life-years (12.7%) had been realized by December 2012. By 2030, benefits reached 17.9 million life-years under current policies, 21.7 million life-years with universal second-line ART, 23.3 million life-years with increased linkage to care of eligible untreated patients, and 28.0 million life-years with both linkage to care and universal second-line ART.Conclusions. We found dramatic past and potential future survival benefits attributable to ART, justifying international support of ART rollout in South Africa.The Journal of Infectious Diseases 12/2013; · 5.85 Impact Factor
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ABSTRACT: Mobile HIV screening may facilitate early HIV diagnosis. Our objective was to examine the cost-effectiveness of adding a mobile screening unit to current medical facility-based HIV testing in Cape Town, South Africa. We used the Cost Effectiveness of Preventing AIDS Complications International (CEPAC-I) computer simulation model to evaluate two HIV screening strategies in Cape Town: 1) medical facility-based testing (the current standard of care) and 2) addition of a mobile HIV-testing unit intervention in the same community. Baseline input parameters were derived from a Cape Town-based mobile unit that tested 18,870 individuals over 2 years: prevalence of previously undiagnosed HIV (6.6%), mean CD4 count at diagnosis (males 423/µL, females 516/µL), CD4 count-dependent linkage to care rates (males 31%-58%, females 49%-58%), mobile unit intervention cost (includes acquisition, operation and HIV test costs, $29.30 per negative result and $31.30 per positive result). We conducted extensive sensitivity analyses to evaluate input uncertainty. Model outcomes included site of HIV diagnosis, life expectancy, medical costs, and the incremental cost-effectiveness ratio (ICER) of the intervention compared to medical facility-based testing. We considered the intervention to be "very cost-effective" when the ICER was less than South Africa's annual per capita Gross Domestic Product (GDP) ($8,200 in 2012). We projected that, with medical facility-based testing, the discounted (undiscounted) HIV-infected population life expectancy was 132.2 (197.7) months; this increased to 140.7 (211.7) months with the addition of the mobile unit. The ICER for the mobile unit was $2,400/year of life saved (YLS). Results were most sensitive to the previously undiagnosed HIV prevalence, linkage to care rates, and frequency of HIV testing at medical facilities. The addition of mobile HIV screening to current testing programs can improve survival and be very cost-effective in South Africa and other resource-limited settings, and should be a priority.PLoS ONE 01/2014; 9(1):e85197. · 3.73 Impact Factor