Harnessing the potential of human immunodeficiency virus self-testing to bolster pre-exposure prophylaxis uptake and achieve UNAIDS targets in sub-Saharan Africa

Despite substantial progress in reducing human immunodeficiency virus (HIV) transmission and acquired immunodeficiency syndrome (AIDS)-related deaths, HIV remains a major public health challenge, particularly in sub-Saharan Africa (1). The Joint United Nations Programme on HIV/AIDS (UNAIDS) has set an ambitious target of having 10 million people on pre-exposure prophylaxis (PrEP) by 2025, recognizing the crucial role of PrEP in HIV prevention (2). PrEP, when taken as prescribed, is highly effective in preventing HIV transmission, and is pivotal to curbing the HIV epidemic (3). Strategies to expand PrEP uptake will therefore be instrumental to achieving the UNAIDS goal.

However, PrEP coverage in sub-Saharan Africa remains far below the UNAIDS target, with less than 10% coverage among individuals at substantial risk (4). This shortfall results from a complex interplay of factors. Limited awareness is a significant issue; only 13.9% of women in five sub-Saharan African countries are aware of PrEP (5). Additionally, there are misconceptions about PrEP’s efficacy and adverse effects. Structural barriers, such as cost and limited availability, also contribute to the problem (5). Several countries in the region have initiated efforts to expand PrEP access through community-based PrEP distribution and task-shifting to include non-physician health workers. Despite these efforts, challenges persist, including limited access to HIV testing, especially in remote areas, and the stigma associated with seeking HIV prevention services at health facilities (6). These barriers hinder PrEP uptake, adherence and continuation, underscoring the need for innovative approaches to enhance PrEP accessibility and acceptability.

In this context, Cox et al. present a modeling study (7) to evaluate the impact of HIV self-testing for PrEP scale-up in western Kenya (7). Their findings are significant, demonstrating that HIV self-testing, when used for PrEP initiation and continuation, can achieve similar health benefits and cost with only marginal increase in risk of drug resistance. This is the first study to illustrate the effectiveness of HIV self-testing in a real-world setting using a well-established and detailed model for HIV transmission (8), addressing a critical gap in the evidence base for this key HIV prevention strategy. A recent systematic review and meta-analysis found that HIV self-testing increased HIV testing uptake and linkage to care among the general population compared to standard approaches (9), further supporting its potential to expand PrEP access and improve HIV prevention outcomes.

The study by Cox et al. evaluated four HIV testing strategies for PrEP delivery: provider-administered nucleic acid testing, provider-administered antibody rapid diagnostic testing, blood-based HIV self-testing, and oral fluid HIV self-testing. While nucleic acid testing has the highest sensitivity, it is also the most expensive and logistically challenging option, often requiring multiple clinic visits. In contrast, HIV self-testing offers greater convenience and privacy, potentially appealing to individuals who might be hesitant to seek testing in traditional healthcare settings. Moreover, it can reduce the burden on healthcare providers, especially in understaffed clinics and can be a safe way to maintain testing services during disruptions such as pandemics, by limiting contact between people and reducing congestion at health facilities.

Previous research has indicated a preference for HIV self-testing among certain populations. For instance, a study in Kenya found that participants in an online pharmacy PrEP program strongly favored self-testing over provider-administered testing (10). This preference could be attributed to the enhanced privacy and autonomy that self-testing affords. However, the primary risk associated with HIV testing modalities, in the context of PrEP initiation, is the potential for false-negative results. This risk is higher with both blood and oral fluid-based HIV self-testing compared to provider-administered tests. False-negative results can lead to individuals with HIV being inappropriately initiated on PrEP instead of being linked to ART treatment, which can subsequently lead to the development of nucleoside reverse transcriptase inhibitor drug resistance, limiting future treatment options for the individual.

The study by Cox et al. found that even with the increased risk of false negatives associated with HIV self-testing, the overall prevalence of drug resistance was not significantly different between the different testing modalities when PrEP was scaled up. In particular, they found that the proportion of HIV infections with PrEP-associated drug resistance was 0.8% in the oral HIV self-testing testing scenario compared to 0.2% in the gold-standard nucleic acid diagnostic testing scenarios. Under their modeled scenario, 75% of the eligible individuals were assumed to link to HIV testing, and of those who tested negative, all initiated PrEP with a 75% probability of continuing on it. However, this optimistic scenario may not fully reflect real-world settings, where barriers to PrEP access and adherence may lower scale-up levels. Field validation through pilot studies across different settings, such as urban and rural areas, would help assess real-world PrEP uptake and drug resistance rates under self-testing models. Nevertheless, by choosing a very high level of PrEP scale up, they illustrate that the risk of wide-spread use of HIV self-testing is minimal and that the benefits of increased PrEP access through self-testing may outweigh the potential risks of drug resistance. By empowering individuals to take control of their HIV prevention, self-testing could lead to increased PrEP uptake and adherence.

UNAIDS has recognized the importance of early diagnosis, setting an interim target that by 2025, 95% of people living with HIV (PLWH) should know their HIV status (11). This effort is closely linked to PrEP implementation, as early diagnosis is essential for identifying individuals who would benefit from PrEP. While progress is being made, there is still much work to be done. In Eastern and Southern Africa, where the HIV epidemic is most severe, the percentage of PLWH who know their status increased from 76% in 2020 to 83% in 2023 (12). This demonstrates substantial progress in a region with a high burden of HIV, yet also highlights the need for continued efforts to reach the remaining undiagnosed individuals. In this context, the widespread distribution of HIV self-testing kits emerges as a pivotal tool for increasing the number of people aware of their HIV status. This strategy offers the advantage of early linkage to care, allowing individuals who test positive to be quickly connected to treatment and support services, potentially preventing further transmission.

A study in Malawi found that after introducing HIV self-testing, the proportion of people who knew their status increased from 78% to 88% (13). This increased awareness can also translate to higher rates of PrEP initiation and adherence, as individuals are more likely to use PrEP consistently when they are confident in their HIV-negative status (14). Therefore, for those who test negative but may be at high risk, self-testing programs can serve as a gateway to other prevention strategies like PrEP or voluntary medical male circumcision. By expanding access to testing and linking individuals to appropriate care and prevention services, HIV self-testing kits can play a crucial role in achieving the UNAIDS 95% target and ultimately ending the AIDS epidemic.

In their evaluation of HIV self-testing for PrEP scale-up, Cox et al. made several assumptions, including high and rapid PrEP uptake, optimistic initiation, and continuation probabilities. While these assumptions may not fully reflect real-world scenarios, potentially overestimating the effectiveness of PrEP scale-up due to barriers in access and adherence, they also assumed the same level of PrEP scale-up under each testing modality, which may not accurately represent real-world scenarios. The benefits of HIV self-testing extend beyond convenience and privacy. By enabling PrEP initiation and monitoring outside of traditional clinic settings, self-testing could significantly expand PrEP reach to underserved communities with limited healthcare access by overcoming structural barriers, such as distance to clinics and limited operating hours. Additionally, self-testing could reduce the burden on healthcare systems by freeing up provider time and resources.

Given the benefits of HIV self-testing for both the healthcare system and individuals, its scale-up is likely to be higher than that of traditional clinic-based testing. For the healthcare system, HIV self-testing is less costly and resource-intensive. For individuals, it offers privacy and convenience. Therefore, the actual impact of using HIV self-testing in expanding PrEP coverage among high-risk individuals on preventing new HIV infections may be far greater compared to traditional clinic-based testing. Future research should evaluate these differences across diverse settings, including urban and rural areas as well as countries with varying HIV prevalence rates. Population-level studies should also examine factors such as adherence to inform evidence-based strategies for PrEP scale-up and fully leverage the potential of HIV self-testing in preventing new infections.

To fully harness the potential of HIV self-testing for PrEP scale-up, policies need to align with emerging evidence through research. As of 2023, only 22 out of 47 countries in sub-Saharan Africa had national policies supporting HIV self-testing (Figure 1), indicating a need for greater policy advocacy and implementation to fully utilize this tool along with PrEP to combat the HIV epidemic. Moreover, the availability and affordability of self-test kits remain major concerns, hindering equitable access. Additionally, the lack of robust distribution networks and post-test support mechanisms pose challenges to the successful integration of HIV self-testing into comprehensive HIV prevention and care programs (17). Complementing the policy changes, future studies should also investigate the optimal implementation strategies for self-testing, including distribution channels, linkage to care for individuals who test positive, and integration with existing health services. Additionally, research should explore the long-term impact of self-testing on PrEP adherence and persistence, as well as the potential for self-testing to reduce stigma associated with HIV prevention.

Figure 1 National policy on HIV self-testing implementation in sub-Saharan Africa (15,16). HIV, human immunodeficiency virus.

The study by Cox et al. underscores the potential of HIV self-testing as a valuable tool in the fight against HIV/AIDS. By offering a convenient, private, and effective alternative to traditional testing methods, self-testing could be a game-changer in expanding PrEP access and achieving the United Nation’s ambitious goal for sub-Saharan Africa. As research continues to elucidate the optimal implementation strategies for self-testing, policymakers, and healthcare providers should consider integrating this innovative approach into their HIV prevention efforts.

Acknowledgments

Funding: None.

Footnote

Provenance and Peer Review: This article was commissioned by the editorial office, Annals of Infection. The article has undergone external peer review.

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References

1. IN DANGER: UNAIDS Global AIDS Update 2022. Geneva: Joint United Nations Programme on HIV/AIDS; 2022. Available online: https://www.unaids.org/sites/default/files/media_asset/2022-global-aids-update-summary_en.pdf
2. AVAC. Cumulative PrEP Initiations 2016-2025. 2024. Available online: https://avac.org/resource/infographic/cumulative-prep-initiations/
3. Fonner VA, Dalglish SL, Kennedy CE, et al. Effectiveness and safety of oral HIV preexposure prophylaxis for all populations. AIDS 2016;30:1973-83. [Crossref] [PubMed]
4. HIV/AIDS Data Hub for the Asia Pacific. The Path That Ends AIDS: 2023 UNAIDS Global AIDS Update. 2023. Available online: https://www.aidsdatahub.org/resource/path-ends-aids-2023-unaids-global-aids-update
5. Terefe B, Jembere MM, Asgedom DK, et al. Knowledge and attitude to HIV pre exposure prophylaxis among women in five sub-Saharan African countries: a multilevel model analysis of population-based survey 2021-2022. BMC Public Health 2024;24:1253. [Crossref] [PubMed]
6. Irungu EM, Baeten JM. PrEP rollout in Africa: status and opportunity. Nat Med 2020;26:655-64. [Crossref] [PubMed]
7. Cox SN, Wu L, Wittenauer R, et al. Impact of HIV self-testing for oral pre-exposure prophylaxis scale-up on drug resistance and HIV outcomes in western Kenya: a modelling study. Lancet HIV 2024;11:e167-75. [Crossref] [PubMed]
8. IDM. Welcome to EMOD HIV modeling. Available online: https://docs.idmod.org/projects/emod-hiv/en/2.20_a/
9. Jamil MS, Eshun-Wilson I, Witzel TC, et al. Examining the effects of HIV self-testing compared to standard HIV testing services in the general population: A systematic review and meta-analysis. EClinicalMedicine 2021;38:100991. [Crossref] [PubMed]
10. Chen Y, Saldarriaga EM, Montano MA, et al. Assessing preferences for HIV pre-exposure prophylaxis (PrEP) delivery services via online pharmacies in Kenya: protocol for a discrete choice experiment. BMJ Open 2023;13:e069195. [Crossref] [PubMed]
11. UNAIDS. End Inequalities. End AIDS. Global AIDS Strategy 2021-2026. Available online: https://www.unaids.org/en/Global-AIDS-Strategy-2021-2026
12. UNAIDS. The path that ends AIDS: UNAIDS Global AIDS Update 2023. 2023. Available online: https://www.unaids.org/en/resources/documents/2023/global-aids-update-2023
13. Sorensen C, Murray V, Lemery J, et al. Climate change and women's health: Impacts and policy directions. PLoS Med 2018;15:e1002603. [Crossref] [PubMed]
14. Machado DM, de Sant'Anna Carvalho AM, Riera R. Adolescent pre-exposure prophylaxis for HIV prevention: current perspectives. Adolesc Health Med Ther 2017;8:137-48. [Crossref] [PubMed]
15. WHO. Global HIV, Hepatitis and STIs Programmes. Available online: https://www.who.int/teams/global-hiv-hepatitis-and-stis-programmes/overview
16. UNAIDS. Global AIDS monitoring. Available online: https://www.unaids.org/en/global-aids-monitoring
17. Kadye T, Jamil MS, Johnson C, et al. Country uptake of WHO recommendations on differentiated HIV testing services approaches: a global policy review. BMJ Open 2024;14:e058098. [Crossref] [PubMed]