Strategic planning for the second era of the HIV epidemic

The global HIV epidemic is more than 40 years old. More than 40 million lives have been lost and approximately 40 million people are living with HIV. 1Bekker LG The HIV epidemic 40 years on. Nat Rev Microbiol. 2023; 21: 767-768Crossref PubMed Scopus (0) Google Scholar Although the US President's Emergency Plan for AIDS Relief (PEPFAR) continues to provide important technical assistance and support in more than 50 countries worldwide, the sense of emergency that characterised the organisation's response to the AIDS epidemic when it was founded in 2003 has evolved. Now, PEPFAR's work increasingly focuses on providing a steady, sustained response aimed at epidemic control. 2Kates J Nandakumar A Gaumer G et al. Assessing PEPFAR's impact: analysis of mortality in PEPFAR countries. Available at: https: //www. kff. org/global-health-policy/issue-brief/assessing-pepfars-impact-analysis-of-mortality-in-pepfar-countries/Date: 2021Date accessed: February 17, 2024Google Scholar Long-term control of the HIV epidemic necessitates optimal use of available interventions in view of budgetary and logistic constraints and changing health priorities. In The Lancet Public Health, Stefan Rautenbach and colleagues describe the use of a mathematical model to predict the impact of reduced general population HIV testing on the South African epidemic up to 2100 if other epidemiological and programmatic conditions remained largely constant. 3Rautenbach SP Whittles LK Meyer-Rath G et al. Future HIV epidemic trajectories in South Africa and projected long-term consequences of reductions in general population HIV testing: a mathematical modelling study. Lancet Public Health. 2024; 9: e218-e230Summary Full Text Full Text PDF Google Scholar Population screening has been a cornerstone policy of the response to the epidemic in South Africa, the country with the largest number of people living with HIV, 4Zuma K Simbayi L Zungu N et al. The HIV epidemic in South Africa: key findings from 2017 national population-based survey. Int J Environ Res Public Health. 2022; 198125 Crossref Scopus (27) Google Scholar but incidence of HIV is falling. Rautenbach and colleagues' modelling study suggests that cost savings from scaling back general HIV testing services might not result in a rapid increase in new HIV infections in the short term. However, reducing the use of general HIV testing could lengthen the time required to reach the threshold of so-called virtual HIV elimination (ie, an incidence of one new infection per 1000 people per year), result in more deaths, and increase requirements for antiretroviral therapy. Overall spending on HIV and AIDS by low-income and middle-income countries in 2022 was around US20·2 billion, almost 9·5 billion of which was donor funding. 5De Cock KM Jaffe HW Curran JW Reflections on 40 Years of AIDS. Emerg Infect Dis. 2021; 27: 1553-1560Crossref PubMed Scopus (50) Google Scholar, 6UNAIDSGlobal HIV 25e25960 Crossref PubMed Scopus (7) Google Scholar In view of challenges such as stagnant funding, competing global priorities, and increasing political disengagement, strategic decision making and management of existing resources to ensure optimal allocation, cost containment, and use of funds and resources will be increasingly important. The saying that, to know the response, you need to know the epidemic, has never been more salient, but knowing your budget and the implications of redistribution are becoming increasingly important. Rautenbach and colleagues aptly show the potential role for mathematical modelling to hypothetically test various scenarios. Although the modelling data reported by Rautenbach and colleagues show the probable epidemiological consequences of policy changes (data that are necessary for future planning), there are some important caveats. The Thembisa model that the authors used might be better suited to projections of the HIV epidemic in South Africa than alternative models, but long-term projections are generally sensitive to input parameters as the uncertainties of future projections amplify over time. The Thembisa model, similar to other models, 8McCormick AW Abuelezam NN Rhode ER et al. Development, calibration and performance of an HIV transmission model incorporating natural history and behavioral patterns: application in South Africa. PLoS One. 2014; 9e98272 Crossref Scopus (14) Google Scholar accounts for several potentially important epidemic parameters (eg, treatment rates, sexual behaviours, transmission) but other important parameters were not considered in this probabilistic analysis, such as changes to prevention behaviours or major health events (eg, events similar to the COVID-19 pandemic). Importantly, a model such as that used by Rautenbach and colleagues might not include comparisons of other possible strategies—eg, redistribution and intensification of HIV testing among specific population groups or in areas with high incidence. Although the overall burden of HIV is high in South Africa, the epidemic looks very different in different parts of the country and among different populations. 9Allinder S Fleischman J The world's largest HIV epidemic in crisis: HIV in South Africa. https: //www. csis. org/analysis/worlds-largest-hiv-epidemic-crisis-hiv-south-africaDate: 2019Date accessed: February 17, 2024Google Scholar Optimal allocation of HIV resources in South Africa could feasibly involve intensification of testing in the areas or populations in which HIV infections are most commonly occurring, along with the deployment of redirected funding to ensure scaling up of novel prevention modalities, such as long-acting pre-exposure prophylaxis, in these same areas or populations. 10Hargreaves JR Auerbach JD Hensen B Johnson S Gregson S Strengthening primary HIV prevention: better use of data to improve programmes, develop strategies and evaluate progress. J Int AIDS Soc. 2020; 23e25538 Google Scholar A potential risk of this strategy is that new outbreaks could potentially be overlooked. Even if dedicated and new funding can be secured for the HIV epidemic, optimised deployment of these funds is necessary. 11Karup KK Ross E Chiossi SL Securing political and financial support for the global HIV response. https: //www. chathamhouse. org/2023/07/securing-political-and-financial-support-global-hiv-response/stepping-global-hiv-responseDate: 2023Date accessed: February 17, 2024Google Scholar Health decisions typically focus on acute cost saving rather than longer-term epidemiological consequences. In an era when health resources are increasingly constrained, modelling studies can help to inform health managers of the long-term consequences of reallocation of resources between diverse competing health priorities. The progress made in the HIV response in many regions of the world could hang in the balance if the wrong decisions are made. There is a risk not only that epidemic control goals could be missed, but that hard-won gains could be lost, with greater costs both in the short term and the long term. L-GB has received honoraria from Gilead, ViiV, and Merck. RW declares no competing interests. Future HIV epidemic trajectories in South Africa and projected long-term consequences of reductions in general population HIV testing: a mathematical modelling studyOur modelling suggests that scaling back of general population HIV testing would not result in a resurgence of HIV infections, but would delay attainment of incidence-reduction targets and result in long-term increases in HIV infections, AIDS-related deaths, and costs (via increased need for ART provision). HIV programmes need to balance short-term potential resource savings with long-term epidemic control objectives. Full-Text PDF Open Access