Improving HIV testing and care for adolescents in Zimbabwe: A targeted, community-based approach

HIV infection is the leading cause of death among adolescents in Africa. There are many reasons for this, including that many adolescents cannot access HIV testing and treatment services. In a recent study, we found that nearly half of adolescents living with HIV in Harare, Zimbabwe, were not aware of their HIV status, despite HIV testing being routinely available at clinics. A different strategy is therefore needed to identify adolescents living with HIV. The aim of our study is to improve the access to HIV testing and linkage to treatment services for adolescents aged 7-18 years in Harare, Zimbabwe. We will offer HIV testing to children of HIV-infected adults attending for care. This targeted strategy of identifying HIV-positive adolescents through parents or caregivers living with HIV is likely to be more efficient than offering testing to all children because children of HIV-positive adults are more likely to be HIV-positive. Adolescents who test HIV positive will be offered support given by community health workers to help them link to and remain in HIV care.

We will address the following questions:
1) Is targeted, home-based HIV testing an effective strategy for identifying undiagnosed HIV in adolescents?
We will initially recruit adults with HIV who attend clinics in 12 study communities. Trained lay counsellors (i.e. non-professional healthcare workers working in primary care clinics who are trained in HIV testing and counselling) will interview these adults to record the age and sex of their household members and whether they have children aged 7-18 years in their household who have not been tested for HIV. They will offer a choice of bringing the adolescent to the clinic for testing or of the counsellor visiting the households of those to offer HIV testing to the adolescent. The main outcomes will be the proportion of adolescents offered HIV testing who undergo testing, and the proportion of those who test HIV-positive among those who are eligible for testing.

2) What is the impact of support provided by community health workers on linkage to and retention in care and response to HIV treatment among HIV-positive adolescents?
Once individuals are diagnosed with HIV, they need to be linked to treatment services. Adolescents who test positive for HIV through our targeted HIV testing strategy will be offered support visits from a community health worker at a location of their choice (home or other community-based location). A previous study in South Africa and Uganda with a similar strategy of home-based HIV testing combined with visits by community health workers, showed that 90% of HIV-positive adults linked to care, and there were improvements in their health outcomes. We will adapt this strategy to make it suitable for adolescents. At 3 home visits over 6 months, participants will be offered age-appropriate HIV information, referrals to local support services, and reminders about clinic attendance. The outcomes will be the proportion of HIV-infected adolescents who do link to an HIV care service and the proportion who have remained in care by 12 months. We will also measure the proportion with a low viral load, a test which measures how well HIV treatment is working.

3) Are these community-based strategies cost-effective?
We will measure how cost-effective our strategy is compared to routinely available services in identifying HIV-infected adolescents and obtaining good outcomes on treatment (i.e. a low viral load).

4) Are these strategies acceptable and what factors need to be addressed to ensure that the intervention can be scaled-up and sustained at a national level if it is effective?
We will conduct a process evaluation to understand how our intervention works, whether it is acceptable to clients and providers and specifically to understand the factors that would need to be considered to ensure the intervention could be delivered widely within the country if it was proven effective.

HIV infection is the leading cause of mortality among adolescents in Africa, and adolescents are the only age group in which HIV-related deaths are rising. Our aim is to improve the access to HIV testing and counselling (HTC) and treatment outcomes for adolescents in Harare, Zimbabwe. Our questions are:
1) Is targeted HTC an effective strategy for identifying undiagnosed HIV in adolescents (aged 7-18 years)?
HIV-positive adults attending for care in the study clinics will be approached by trained lay counsellors. Consent will be obtained to visit the households of those who have untested adolescents to offer HTC, with an option to bring adolescents to the clinic for HTC if preferred. The outcomes will be uptake of HTC (proportion of those offered testing who undergo testing) and yield of HIV (proportion of those who test positive among those eligible for testing).
2) What is the impact of support provided by community health workers (CHWs) on linkage to and retention in care and virological suppression among HIV-positive adolescents?
Participants who test positive through targeted HTC will be offered support visits at 1, 2 and 6 months following diagnosis from a CHW, referrals to support services and reminders about appointments. Outcomes will be proportion linked to and retained in care by 12 months and viral load at 12 months.
3) Are these community-based strategies cost-effective?
The cost per individual tested and cost per HIV-positive adolescent identified through home-based HTC will be estimated. The cost per HIV-positive adolescent initiated on ART, and cost per HIV-positive adolescent virally suppressed on ART will also be assessed.
4) What implementation, mechanism and contextual factors affect the delivery and acceptability of targeted HTC and CHW support?
A mixed-methods process evaluation of the intervention, mechanisms of impact and of local context will be conducted, to inform the components required for sustainability and scalability.

Of the estimated 2.1 million adolescents living with HIV globally, 82% live in sub-Saharan Africa, and HIV is the leading cause of death among adolescents in this region. Globally, nearly two-thirds of adolescents living with HIV are unaware of their HIV status, and are thus not accessing care. Of those who are diagnosed and eligible for treatment, only about a third are linked to HIV care services. Existing strategies to deliver HIV testing and counselling are insufficient in identifying adolescents living with HIV and engaging them with care services. UNAIDS has set ambitious targets to identify 90% of HIV-positive persons through testing, initiate 90% of them on antiretroviral therapy (ART), and achieve viral suppression in 90% by 2020 (90-90-90 targets). In addition the 2015 WHO HIV treatment guidelines recommended immediate initiation of ART in all individuals regardless of age, disease stage or CD4 count. To achieve the ambitious 90-90-90 targets, particularly under the expanded criteria for ART, there is an urgent need to improve HIV testing and engagement with HIV services among adolescents. Adolescents are a key population for HIV prevention and treatment, are difficult to reach through clinic-based interventions, and have disproportionately poor treatment success rates. Current strategies replicate those that exist for adults without taking into account the structural, social and legal barriers faced by adolescents in accessing HIV testing and treatment.

Provider-initiated HIV testing and counselling for all attendees to health facilities in high-burden countries has been recommended by WHO since 2007. However, health services often do not prioritise adolescents for HIV testing and furthermore health facility usage rates by this age-group are low. Community-based strategies, particularly home-based HIV testing, have resulted in high uptake of HIV testing but a low yield due to low prevalence of HIV in the community. We will use a targeted approach to home-based testing by offering home-based HIV testing to adolescent children of HIV-infected adults. Children of adults living with HIV are at substantially higher risk of being HIV-positive themselves and therefore this approach will address both the facility-level barriers to HIV testing among adolescents, and also increase the yield of identifying adolescents living with undiagnosed HIV, resulting in a highly efficient and cost-effective strategy. However, identifying individuals with undiagnosed HIV will only result in successful treatment outcomes if combined with an effective strategy to enhance uptake of and retention in care. We aim to integrate HIV testing with support provided to adolescents and their caregivers to encourage linkage to and retention in care. Given the substantial burden of HIV in sub-Saharan Africa and the increasing numbers of people who will require life-long care, many high-burden countries have moved towards utilising lay workers to provide HIV testing and support, and this approach is now recommended by WHO. Our proposed intervention will be delivered by non-professional trained health workers, which will facilitate scalability and sustainability should the intervention be effective.

Adolescents are the only age group in whom HIV-associated mortality is rising despite the global scale-up of ART delivery. Viral suppression in HIV-positive individuals is the ultimate goal to improve health outcomes and reduce HIV transmission, thus conferring individual and public health benefits. Our project will address the whole cascade of HIV care including testing, supporting linkage to and retention in care, which we anticipate will improve virological suppression rates in an age-group that not only has the highest HIV incidence rates but also the worst care outcomes.