Content available: Audio Recording Vietnam estimates 8.8 million persons living with hepatitis B (HBV) and C virus (HCV) infection and reports 40,000 deaths annually; however, 80%–90% infected people remain undiagnosed, and 95% of treatment eligible people remain untreated.1-5 Limited community awareness about the disease, passive case finding approaches, and low availability of hepatitis services at the primary health care level present barriers to testing scale-up. There have been calls for the decentralization and integration of hepatitis testing to improve access to testing, linkage to care and treatment,6-9 but limited empirical evidence on effective hepatitis testing service delivery models exists. In this paper, we present preliminary results from the HepLINK project, funded by The Hepatitis Fund, and implemented by PATH and Vietnam's Ministry of Health (MOH). HepLINK implements community-based (CBT) and facility-based testing (FBT) for HBV/HCV through integration with HIV services in Hanoi and Ho Chi Minh City to accelerate HBV/HCV testing uptake and treatment access among key populations (KPs) including people who inject drugs (PWID), non-injecting drug users (DU), men who have sex with men (MSM), female sex workers (FSW), and transgender women (TGW). We engaged 9 KP-led community-based organizations (CBOs), 6 KP-led private clinics, and 12 public outpatient and methadone maintenance treatment (MMT) clinics in providing systematic screening for HBV/HCV and making referral/linkage to HCV/HBV confirmatory testing, diagnosis, and treatment. Targeted HBV/HCV demand creation activities were co-created and implemented with CBOs and clinics. Clients seeking HIV testing, pre-exposure prophylaxis (PrEP), non-occupational post-exposure prophylaxis (nPEP), antiretroviral therapy (ART), and MMT received counseling and testing for HBsAg and anti-HCV, using a single finger prick rapid diagnostic test (i.e., Alere Determine™ HBsAg and SD Bioline HCV). Those with a reactive test result were linked to the nearest health facility for further care (Figure 1). From April to October 2021, we reached 8840 people, of which the great majority of people (86.9%) accepted HBsAg testing, yielding 689 (9%) positive cases. Key reasons for not accepting HBsAg included low awareness of HBV/HCV risk, not yet having tested for HIV, fear of having another disease (ART patients), low knowledge of HBV/HCV treatability/curability, and craving for drugs (PWID). Among the 7683 people tested, 16.1% were aged 15–24 years old and 78.7% were aged 25–49 years old, and 85.1% self-identified as KP (PWID 37.5%, MSM 30%, DU 13.3%, FSW 2.7%, and TGW 1.6%). As shown in Figure 2, CBT reached more clients and yielded a higher HBsAg positivity rate than FBT (11.5% and 4.9%, respectively), whereas FBT diagnosed more persons with current HCV infection and enrolled a higher rate of eligible persons on treatment (90% and 62.1%, respectively). Of 8840 people offered testing, nearly all (94%) accepted anti-HCV testing, yielding 941 (11.3%) positive cases. People who did not uptake anti-HCV testing shared the same reasons as those who did not accept HBsAg testing. CBT reached and tested more clients, but unlike with HBV, yielded lower positivity rate than FBT (6.7% and 18.4%, respectively). CBT had lower rate of anti-HCV positive clients receiving HCV virologic testing but achieved a higher rate of HCV-confirmed cases compared to FBT (42.7% and 88.2% compared to 62.3% and 62%) (Figure 3). HBV (HBsAg+) infection rate was highest in FSW (20.8%; 44/212), followed by PWID (11.1%; 319/2878), DU (9.5%; 97/1022), MSM (5.9%; 136/2312), and TGW (2.6%; 3/117). HBV-HIV co-infection rate was 9.6% (169/1761). A multivariable analysis (Table 1) showed a significant association between HBV positivity and older age of clients tested with those 50+ years old at three times greater odds of HBV infection (adjusted odds ratio [aOR] = 2.96; 95% confidence interval [CI]: 1.99–4.42); using CBT (aOR = 2.67; 95%CI: 2.09–3.40); being a FSW (aOR = 2.56; 95%CI: 1.62–4.05); not being HBV vaccinated (aOR = 2.24; 95%CI: 1.43–3.51); and being an nPEP user, ART patient, or HIV testing client. Similarly, HCV (anti-HCV) infection rate was highest in PWID (20.9%; 637/3044), followed by DU (6.8%; 88/1289), FSW (3.9%; 8/205), TGW (2.6%;3/115), and MSM (1.9%; 47/2427). HCV-HIV co-infection rate was exceptionally high (28.4%; 556/1957). A multivariable analysis (Table 2) confirmed a significant association between HCV sero-positivity and older age of clients tested with those 25+ years old (aOR = 1.81; 95%CI: 1.18–2.78); being a PWID (aOR = 11.37; 95%CI: 8.73–14.81), DU (aOR = 3.44; 95%CI: 2.49–4.77), FSW (aOR = 2.34; 95%CI: 1.05–5.23), or PLHIV (aOR = 5.85; 95%CI: 4.15–8.23); and using PrEP (aOR = 4.21; 95%CI: 2.08–8.52) or nPEP(aOR = 3.13; 95%CI: 1.33–7.35). It also confirmed a significant inverse association between HCV sero-positivity and being MSM (aOR = 0.31; 95%CI: 0.22–0.46) and using CBT (aOR = 0.16; 95%CI: 0.13–0.20). Although FBT diagnosed and enrolled a higher rate of eligible treatment people on HBV treatment, ART (TLD regimen) and PrEP (TDF/FTC regimen) than CBT, CBT enrolled more clients on HBV treatment, ART, and PrEP (15, 103 and 10 compared to 8, 63 and 1, respectively) (Figure 4). Only around half of HBsAg+ clients (42.8% and 55.1%) received HBV treatment eligibility evaluation due to the unavailability of viremia confirmatory testing and fibrosis testing at the district level. As a result of advocacy from the HIV program, Vietnam's social health insurance (SHI) circular was recently revised to allow transportation of blood samples for viremia confirmatory testing for both outpatients and inpatients from district health facilities (effective from February 2022). We expect this will increase uptake of viremia confirmatory testing and subsequent linkage to HBV treatment (Figure 4). Similarly, the fall off from anti-HCV+ to HCV confirmatory testing was associated with complex requirements by SHI on referring clients for HCV confirmatory test. As an advantage of linkage to care FBT successfully linked a higher rate of anti-HCV+ clients to confirmatory testing than CBT (62.3% and 42.7%, respectively). HCV treatment access was limited in both CBT and FBT (39.4% and 37.3%, respectively) due to the current cost of DAAs and co-payment required by SHI (Figure 5). Our community-based and HIV integrated HBV/HCV testing model showed high acceptability among KPs and can be a powerful tool for increasing HBV/HCV uptake by targeting the same populations, at the same time, and in the same location.2, 3, 10-12 Access to viremia testing and treatment remains challenging; consequently, progress toward HBV/HCV elimination is still far off. This approach is effective in detecting HBV/HCV infected people and showing which KPs may be at highest risk of HBV/HCV infection in particular settings. Both CBT and FBT achieved high positivity yield of HBV and HCV infection. This suggests that the model successfully reached and tested populations at increased risk of HBV/HCV infection. The multivariable analysis identified client groups with the highest rates of infection, which can inform targeted hepatitis testing programming for a high positivity yield. A system for linkage from screening to appropriate care and treatment for HBV/HCV was established and facilitated by HepLINK-supported KP-led CBOs and clinics. The hepatitis-HIV integrated model created a tremendous opportunity for people living with HBV to access free ART or PrEP using a tenofovir regimen that is also effective for HBV treatment. Continuing efforts to ensure low cost or free treatment will be essential to increasing uptake of treatment and care. The implementation research included only clients using HIV services. This restricted our ability to determine the true impact of the intervention on key outcomes. A follow-up-controlled study would be ideal to examine the impact of the intervention. Routine monitoring data from e-logbooks were used in the analysis of the intervention's effectiveness, which prevented us from conducting statistical power analysis. Data on confirmatory tests, liver cirrhosis stage, and treatment among clients diagnosed because of the intervention were difficult to track in higher-level health facilities. Thus, we were not able to follow-up treatment results. We envision that the next steps needed to improve HBV/HCV testing uptake and treatment access among KP in Vietnam may include scaling up CBT and FBT models, piloting HCV self-testing and point-of-care viral load (VL) testing (e.g., GeneXpert), and engaging private sector suppliers through a shared-valued approach to offer more affordable VL testing and DAAs. Community-based and HIV integrated testing for HBV/HCV is a promising strategy to accelerate testing uptake, case detection, and linkage to care for KPs that may otherwise not test for HBV/HCV. Further work is needed in Vietnam to improve access to HBV/HCV confirmatory testing, diagnosis, and treatment to achieve viral hepatitis elimination by 2030. HepLINK is funded with a grant from The Hepatitis Fund (aka EndHep2030). We are grateful to the Vietnam Administration of Medical Services (VAMS) and Vietnam Administration of HIV/AIDS Control (VAAC) for their collaboration and support in implementing the project. We would like to acknowledge the Centers for Disease Control (CDC) of Hanoi and Ho Chi Minh City, district health centers, KP-led CBOs and private clinics for their dedication and commitment on implementation of the project. Thanks to Abbott Diagnostics for donation of HBV and HCV RDT tests to the project. Special thanks to Zoe Humeau for her review and edits to improve this manuscript. Nothing to report.