CHAPTER ONE

INTRODUCTION

1.1 Background to the Study

Sub-Saharan Africa carries the heaviest burden of HIV in the world. UNAIDS estimates that about 1.3 million people acquired HIV and 630,000 died of AIDS-related illnesses worldwide in 2024, and that sub-Saharan Africa was home to about half of all people living with HIV (UNAIDS, 2025). The region has made real progress: new infections there have fallen by more than half since 2010, and AIDS-related deaths have fallen sharply (UNAIDS, 2025). In eastern and southern Africa, the region most affected, new infections fell by 59% between 2010 and 2023 (UNAIDS, 2024). Even so, UNAIDS warns that progress is now threatened by a sudden fall in international funding and that millions of additional infections and deaths could follow if action is not taken (UNAIDS, 2025).

Young people, and young women in particular, remain at greatest risk. Women and girls account for about 63% of new infections in sub-Saharan Africa, and about 4,000 adolescent girls and young women aged 15–24 acquire HIV every week (UNAIDS, 2025). In eastern and southern Africa, adolescent girls and young women are three times as likely to acquire HIV as their male peers (UNAIDS, 2024). In 2024, adolescent girls accounted for 71% of all new HIV infections among adolescents aged 15–19 worldwide, and in sub-Saharan Africa almost six times as many adolescent girls as boys were newly infected (UNICEF, 2025).

HIV testing is the entry point to both prevention and treatment, but young people are tested far less often than they need to be. In eastern and southern Africa, only 29% of adolescent girls and 19% of adolescent boys aged 15–19 had been tested for HIV in the previous twelve months and received the result (UNICEF, 2025). Young people who test positive then face further losses along the HIV treatment cascade, which runs from testing and diagnosis through linkage to care, retention, adherence to antiretroviral therapy (ART) and viral suppression. Adolescents living with HIV are an under-served group with poor retention in care and high mortality, and retention is substantially lower for them than for other age groups (“Improving retention in HIV care among adolescents and adults in low- and middle-income countries,” 2017).

Because facility-based services have limits, programmes have increasingly moved services into communities. Community-based approaches include home-based and mobile testing, HIV self-testing distributed through peers, community drug distribution, adherence clubs and support groups. Many of these approaches rely on non-professional providers such as community health workers, lay counsellors, peer educators and volunteers. Sub-Saharan Africa has only about 3% of the world’s health workforce, and lay health workers have been proposed as a way of extending services through task-shifting (Mwai et al., 2013). A systematic review of community health workers in HIV care in sub-Saharan Africa concluded that they can clearly contribute to HIV service delivery and strengthen human resource capacity (Mwai et al., 2013).

The evidence on how well these approaches work for young people is mixed. A review of retention interventions found that community-based services showed the most robust evidence for improving retention in care, but that most of the evidence came from adults. A community-based service delivery model that was effective for adults had no effect among youths, and only one study evaluated a retention intervention specifically for youth (“Improving retention in HIV care among adolescents and adults in low- and middle-income countries,” 2017). Other work has found that community-based testing reduces barriers to testing, but that people identified through community testing may be less likely to link to care, or may take longer to do so, than those identified in facilities (“Systematic review of linkage to care following community-based HIV testing in sub-Saharan Africa,” n.d.). These findings show the need to examine carefully which community-based interventions are effective for youths, and under what conditions.

1.2 Statement of the Problem

Young people in sub-Saharan Africa are at high risk of HIV infection, yet fewer than a third of adolescents in the worst-affected region have recently been tested, and young people living with HIV are more likely than adults to drop out of care (UNICEF, 2025; “Improving retention in HIV care among adolescents and adults in low- and middle-income countries,” 2017). Community-based interventions delivered by lay and non-professional providers have been widely adopted to extend testing, treatment and care, but most of the evidence for their effectiveness comes from studies of adults, and findings for youths are inconsistent. Funding cuts have increased the pressure to identify approaches that are effective and affordable (UNAIDS, 2025). There is therefore a need to bring together and assess the evidence on how effective community-based HIV interventions are for youths in sub-Saharan Africa, in testing, in treatment and care, in retention and in prevention.

1.3 Aim and Objectives of the Study

The aim of the study is to assess the effectiveness of community-based HIV interventions among youths in sub-Saharan Africa. The specific objectives are to:

1. assess the effectiveness of community-based HIV testing approaches in increasing testing uptake and linkage to care among youths;
2. evaluate the effectiveness of community-based HIV treatment and care for youths living with HIV;
3. examine the role and effectiveness of non-professional (lay) HIV service providers in delivering services to youths;
4. determine the effect of community-based interventions on retention in HIV care among youths; and
5. identify the community-based approaches that contribute to HIV prevention among youths in sub-Saharan Africa.

1.4 Research Questions

The study is guided by the following research questions:

1. How effective are community-based HIV testing approaches in increasing testing and linkage to care among youths in sub-Saharan Africa?
2. How effective is community-based HIV treatment and care for youths living with HIV?
3. What is the role of non-professional HIV service providers, and how effective are they in serving youths?
4. What effect do community-based interventions have on retention in HIV care among youths?
5. Which community-based approaches contribute to HIV prevention among youths?

1.5 Significance of the Study

The study should be of value to several groups. Policymakers and national AIDS programmes can use it to decide which community-based approaches to fund and scale up for young people, which matters all the more as funding becomes scarcer (UNAIDS, 2025). Programme managers and non-governmental organisations can use the findings to design youth-friendly services and to train and support lay providers. Health workers and community-based providers can use it to understand what works for young people, and researchers will find a summary of the evidence and its gaps, such as the shortage of studies designed specifically for adolescents and youths (“Improving retention in HIV care among adolescents and adults in low- and middle-income countries,” 2017). Ultimately, the study aims to contribute to improved testing, treatment and retention outcomes for young people and to progress towards ending AIDS as a public health threat.

1.6 Scope of the Study

The study covers community-based HIV interventions for youths in sub-Saharan Africa. Youths are defined as people aged 15–24 years, although studies that include adolescents aged 10–19 are considered where they report results for young people. The study covers four areas: HIV testing (including home-based, mobile and self-testing approaches), community-based treatment and care, retention in care, and HIV prevention, with particular attention to interventions delivered by non-professional providers. It focuses on evidence from sub-Saharan African countries, and facility-based interventions are considered only for comparison.

1.7 Definition of Terms

Youth: A person aged 15–24 years. Adolescents are people aged 10–19 years.

Community-based HIV intervention: A programme that delivers HIV testing, prevention, treatment or care outside a health facility, for example in homes, schools, community venues or through mobile outreach.

Non-professional (lay) service provider: A person without formal professional health qualifications, such as a community health worker, peer educator, lay counsellor or volunteer, who provides health services or support (Mwai et al., 2013).

Retention in care: Continued engagement of a person living with HIV in HIV care services over time, including attending appointments and remaining on treatment.

Linkage to care: The process by which a person who has been diagnosed with HIV enrols in HIV care and starts treatment.

HIV treatment cascade: The sequence of steps in HIV care, from testing and diagnosis through linkage, retention, ART adherence and viral suppression.

References

Improving retention in HIV care among adolescents and adults in low- and middle-income countries: A systematic review of the literature. (2017). PLoS ONE. https://doaj.org/article/9d783d8021674a9fb852948d9fc894e2

Mwai, G. W., Mburu, G., Torpey, K., Frost, P., Ford, N., & Seeley, J. (2013). Role and outcomes of community health workers in HIV care in sub-Saharan Africa: A systematic review. Journal of the International AIDS Society, 16(1), 18586.

Systematic review of linkage to care following community-based HIV testing in sub-Saharan Africa. (n.d.). https://pmc.ncbi.nlm.nih.gov/articles/PMC6063407

UNAIDS. (2024). Eastern and southern Africa regional profile: 2024 global AIDS update. UNAIDS. https://unaids.org/en/resources/documents/2024/2024-unaids-global-aids-update-eastern-southern-africa

UNAIDS. (2025). AIDS, crisis and the power to transform: Global AIDS update 2025. UNAIDS.

UNICEF. (2025). HIV/AIDS: Adolescents and young people. UNICEF Data. https://data.unicef.org/topic/hivaids/adolescents-young-people/