Background Many mathematical models have investigated the impact of expanding access to antiretroviral therapy (ART) on new HIV infections. Comparing results and conclusions across models is challenging because models have addressed slightly different questions and have reported different outcome metrics. This study compares the predictions of several mathematical models simulating the same ART intervention programmes to determine the extent to which models agree about the epidemiological impact of expanded ART. Methods and Findings Twelve independent mathematical models evaluated a set of standardised ART intervention scenarios in South Africa and reported a common set of outputs. Intervention scenarios systematically varied the CD4 count threshold for treatment eligibility, access to treatment, and programme retention. For a scenario in which 80% of HIV-infected individuals start treatment on average 1 y after their CD4 count drops below 350 cells/µl and 85% remain on treatment after 3 y, the models projected that HIV incidence would be 35% to 54% lower 8 y after the introduction of ART, compared to a counterfactual scenario in which there is no ART. More variation existed in the estimated long-term (38 y) reductions in incidence. The impact of optimistic interventions including immediate ART initiation varied widely across models, maintaining substantial uncertainty about the theoretical prospect for elimination of HIV from the population using ART alone over the next four decades. The number of person-years of ART per infection averted over 8 y ranged between 5.8 and 18.7. Considering the actual scale-up of ART in South Africa, seven models estimated that current HIV incidence is 17% to 32% lower than it would have been in the absence of ART. Differences between model assumptions about CD4 decline and HIV transmissibility over the course of infection explained only a modest amount of the variation in model results. Conclusions Mathematical models evaluating the impact of ART vary substantially in structure, complexity, and parameter choices, but all suggest that ART, at high levels of access and with high adherence, has the potential to substantially reduce new HIV infections. There was broad agreement regarding the short-term epidemiologic impact of ambitious treatment scale-up, but more variation in longer term projections and in the efficiency with which treatment can reduce new infections. Differences between model predictions could not be explained by differences in model structure or parameterization that were hypothesized to affect intervention impact. Please see later in the article for the Editors' Summary

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We hypothesized that rapid presentation may be a general feature of tuberculosis (TB) associated with human immunodeficiency virus (HIV) that limits the impact of HIV on the point prevalence of TB. To investigate this, we performed a cross-sectional HIV and TB disease survey with retrospective and prospective follow-up. HIV prevalence among 1,773 systematically recruited miners was 27%. TB incidence was much more strongly HIV associated (incidence rate ratio, 5.5; 95% confidence interval [CI], 3.5-8.6) than the point prevalence of undiagnosed TB disease (odds ratio, 1.7; 95% CI, 0.9-3.3). For smear-positive TB, 7 of 9 (78%) prevalent cases were HIV negative, and point prevalence was nonsignificantly lower in miners who were HIV positive (odds ratio, 0.8; 95% CI, 0.1-4.2). The calculated mean duration of smear positivity before diagnosis (point prevalence/incidence) was substantially shorter for HIV-positive than HIV-negative TB patients (0.17 and 1.15 years, respectively; ratio, 0.15; 95% CI, 0.00-0.73). HIV has considerably less impact on the point prevalence of TB disease than on TB incidence, probably because rapid disease progression increases presentation and casefinding rates. The difference in mean duration of smear positivity was particularly marked and, if generalizable, will have major implications for TB control prospects in high HIV prevalence areas.

BackgroundAntiretroviral Treatment (ART) significantly reduces HIV transmission. We conducted a cost-effectiveness analysis of the impact of expanded ART in South Africa.MethodsWe model a best case scenario of 90% annual HIV testing coverage in adults 15–49 years old and four ART eligibility scenarios: CD4 count <200 cells/mm3 (current practice), CD4 count <350, CD4 count <500, all CD4 levels. 2011–2050 outcomes include deaths, disability adjusted life years (DALYs), HIV infections, cost, and cost per DALY averted. Service and ART costs reflect South African data and international generic prices. ART reduces transmission by 92%. We conducted sensitivity analyses.ResultsExpanding ART to CD4 count <350 cells/mm3 prevents an estimated 265,000 (17%) and 1.3 million (15%) new HIV infections over 5 and 40 years, respectively. Cumulative deaths decline 15%, from 12.5 to 10.6 million; DALYs by 14% from 109 to 93 million over 40 years. Costs drop $504 million over 5 years and $3.9 billion over 40 years with breakeven by 2013. Compared with the current scenario, expanding to <500 prevents an additional 585,000 and 3 million new HIV infections over 5 and 40 years, respectively. Expanding to all CD4 levels decreases HIV infections by 3.3 million (45%) and costs by $10 billion over 40 years, with breakeven by 2023. By 2050, using higher ART and monitoring costs, all CD4 levels saves $0.6 billion versus current; other ART scenarios cost $9–194 per DALY averted. If ART reduces transmission by 99%, savings from all CD4 levels reach $17.5 billion. Sensitivity analyses suggest that poor retention and predominant acute phase transmission reduce DALYs averted by 26% and savings by 7%.ConclusionIncreasing the provision of ART to <350 cells/mm3 may significantly reduce costs while reducing the HIV burden. Feasibility including HIV testing and ART uptake, retention, and adherence should be evaluated.

This article undertakes a content analysis of publications in the first 10 years of the new series of the journal Accounting History. In so doing, it adds to the prior literature examining publishing patterns in the accounting history discipline. The article commences by providing an historical background to the introduction of the new series and the journal's editorial team. This is followed by a content analysis of the journal's research publications. This analysis examines patterns of authorship, the journal's most published authors, institutional and geographical affiliations of authors, author gender and article classifications.

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SUMMARYRecent population genetic studies on the malaria parasite Plasmodium falciparum have confirmed that selfing is more frequent where the transmission rate is lower, with inbreeding coefficients estimated to be 0.33 and 0.92 for sites in Tanzania and Papua New Guinea (PNG), respectively. These geographical differences in Plasmodium mating patterns have been linked to the rate of spread of chloroquine resistance (C R) which, according to some measures, has been slower in Tanzania than in PNG. It has been proposed that the former observation explains the latter, although the theoretical argument linking the two is based on limited simulation studies. Taking a more analytical approach here, we first establish the relevant relationship between the coefficient of inbreeding (F, within loci) and the recombination rate (r, between loci), defining an ' effective recombination rate ', rg l r(1kF ). We then show that the emergence of multigenic drug resistance can indeed be slowed (or even quickened) by more outcrossing, but only when resistance is determined by two or more genes, none of which independently confers significant protection. The resistance genes should both be initially rare, and subject to low selection pressure. The analysis does not completely discount the hypothesis that inbreeding significantly influences the spread of C R, but we show that it can only do so under a restrictive set of conditions, and that these conditions are not satisfied by some laboratory and field data. We discuss some of the wider implications of these results for the evolution of multigenic resistance.

The HIV-1 epidemic has increased the malaria disease and death rate in southern Africa.