Background: Hepatitis B virus (HBV) is a neglected public health threat with poor community awareness and access to prevention, despite having a safe and effective vaccine. There are still gaps in diagnosis and treatment, particularly in the World Health Organization (WHO) African region. New WHO HBV guidelines, for the first time, include the use of dual therapy for HBV treatment (Tenofovir (TDF) and Emtricitabine or Lamivudine (XTC) due to challenges in accessing TDF monotherapy. TDF/XTC is also recommended as Pre-Exposure Prophylaxis (PrEP) in adolescents and adults at risk of Human Immunodeficiency Virus (HIV). HBV Screening, treatment and prevention need to be decentralized to improve access. We hypothesize that HBV programmes in African settings can use pre-existing HIV infrastructure, in particular building on PrEP programmes, for access to TDF. Materials and methods: At the Africa Health Research Institute (AHRI) in KwaZulu Natal, South Africa, the new Evaluation of Vukuzazi LiVEr disease - Hepatitis B (EVOLVE-HBV, UCL ethics ref. 23221/001) research programme explored the PrEP uptake and retention cascade amongst adolescents and youth aged 15-30 year-olds living with HBV through decentralized sexual health /HIV services of the (Thetha nami ngithethe nawe) and the Long-acting HIV Pre-Exposure Prophylaxis (LAPIS) study (UKZN BREC ethics ref. 473/2019 and 3735/2021). Following point of care testing (POCT) for HBsAg, follow-up venous samples were taken for laboratory confirmation. Results: Over the time reviewed (May 2021 - Sept 2024), 15,847 adolescents and young adults received a (needs assessment) by peer navigators in the community, of whom 3481 (21.9%) were eligible for HIV prevention interventions and referred for clinical review. 3431 (98.6%) accepted HBV POCT as part of routine screening, of whom 21 (0.6%) tested positive for HBsAg. These 21 individuals had not previously been aware of their HBV status, but one was already on antiretroviral (ART) for HIV infection. Amongst the remaining 20, 16 were considered eligible for PrEP, 1/16 (6.3%) decided not to take it and 15 (93.8%) started PrEP as a combined intervention for HBV treatment and HIV prophylaxis. When investigating follow up and retention in care, out of the 14/15 (93.3%) that were due for a refill, 8/14 (57,1%) returned for at least 1 refill, amongst whom 6/12 (50%) had two or more refills (Suppl figure 1). Conclusions: Sexual health and PrEP programmes provide an important opportunity for HBV testing and treatment for young adults across high HIV burden settings. However, attrition from the care cascade at each step highlights the pressing need for interventions that address barriers to sustainable delivery of long-term care. Our HBV and PrEP programmes continue working to support education, clinical evaluation and service development for HBV in these populations.