IntroductionThough Senegal has one of the highest estimated prevalence rates of chronic hepatitis B virus (HBV) infection worldwide, epidemiological data in the general population are lacking and consequences of the infection remain undocumented. The ANRS-12356 AmBASS study aims at evaluating the health and socioeconomic burden of chronic HBV infection at the individual, household and population level. Its specific objectives are (1) to document the epidemiology of chronic HBV infection, including prevalence and risk factors; (2) to assess the acceptability of home-based testing and first clinic visit; (3) to investigate the repercussions of chronic HBV infection on living conditions; and (4) to estimate the public health impact of chronic HBV infection at the population level and the feasibility of a decentralised model of HBV test and treat.Methods and analysisThis multidisciplinary cross-sectional survey includes a twofold data collection: (1) home-based screening using dried blood spot (DBS) sampling and collection of sociodemographic, economic and behavioural data, and (2) additional clinical and biological data collection in chronic HBV carriers at the first clinic visit. The prevalence of chronic HBV infection will be estimated in the general population and in key subgroups. Risk factors for HBV acquisition in children will be explored using case-control analysis. HBV burden will be assessed through comparisons of health and economic outcomes between households affected by the disease versus non-affected households. Last, an economic evaluation will assess costs and health benefits of scaling-up HBV care.Ethics and disseminationThis study was approved by the Senegalese National Ethical Committee for Research in Health, and received authorisation from the Senegalese Ministry of Health and the French Commission on Information Technology and Liberties (Senegalese Protocol Number: SEN17/15). The study results will be presented in peer-review journals, international conferences and at a workshop with national stakeholders in order to contribute to the design of programmes to address the HBV pandemic.Trial registration numberNCT03215732; Pre-results.

Senegal introduced the infant hepatitis B virus (HBV) vaccination in 2004 and recently committed to eliminating hepatitis B by 2030. Updated epidemiological data are needed to provide information on the progress being made and to develop new interventions. We estimated the prevalence of hepatitis B surface antigen (HBsAg) in children and adults living in rural Senegal and assessed hepatitis B treatment eligibility. A cross‐sectional population‐based serosurvey of HBsAg was conducted in 2018‐2019 in a large sample (n = 3,118) of residents living in the Niakhar area (Fatick region, Senegal). Individuals positive for HBsAg subsequently underwent clinical and biological assessments. Data were weighted for age and sex and calibrated to be representative of the area’s population. Among the 3,118 participants, 206 were HBsAg positive (prevalence, 6.9%; 95% confidence interval [CI], 5.6‐8.1). Prevalence varied markedly according to age group in individuals aged 0‐4, 5‐14, 15‐34, and ≥35 years as follows: 0.0% (95% CI, 0.00‐0.01); 1.5% (95% CI, 0.0‐2.3); 12.4% (95% CI, 9.1‐15.6); and 8.8% (95% CI, 6.1‐11.5), respectively. Of those subsequently assessed, 50.9% (95% CI, 41.8‐60.0) had active HBV infection; 4 (2.9%; 95% CI, 0.9‐9.4) were eligible for hepatitis B treatment. Conclusion: In this first population‐based serosurvey targeting children and adults in rural Senegal, HBsAg prevalence was very low in the former, meeting the World Health Organization’s (WHO) < 1% HBsAg 2020 target; however, it was high in young adults (15‐34 years old) born before the HBV vaccine was introduced in 2004. To reach national and WHO hepatitis elimination goals, general population testing (particularly for adolescents and young adults), care, and treatment scale‐up need to be implemented.

Increasing demand for antiretroviral treatment (ART) together with a reduction in international funding during the last decade may jeopardize access to ART. Using data from a cross-sectional survey conducted in 2014 in 19 HIV services in the Centre and Littoral regions in Cameroon, we investigated the role of healthcare supply-related factors in time to ART initiation in HIV-positive patients eligible for ART at HIV diagnosis. HIV service profiles were built using cluster analysis. Factors associated with time to ART initiation were identified using a multilevel Cox model. The study population included 847 HIV-positive patients (women 72%, median age: 39 years). Median (interquartile range) time to ART initiation was 1.6 (0.5–4.3) months. Four HIV service profiles were identified: (1) small services with a limited staff practising partial task-shifting (n = 4); (2) experienced and well-equipped services practising task-shifting and involving HIV community-based organizations (n = 5); (3) small services with limited resources and activities (n = 6); (4) small services providing a large range of activities using task-shifting and involving HIV community-based organizations (n = 4). The multivariable model showed that HIV-positive patients over 39 years old [hazard ratio: 1.26 (95% confidence interval) (1.09–1.45), P = 0.002], those with disease symptoms [1.21 (1.04–1.41), P = 0.015] and those with hepatitis B co-infection [2.31 (1.15–4.66), P = 0.019] were all more likely to initiate ART early. However, patients in the first profile were less likely to initiate ART early [0.80 (0.65–0.99), P = 0.049] than those in the second profile, as were patients in the third profile [association only significant at the 10% level; 0.86 (0.72–1.02), P = 0.090]. Our findings provide a better understanding of the role played by healthcare supply-related factors in ART initiation. In HIV services with limited capacity, task-shifting and support from community-based organizations may improve treatment access. Additional funding is required to relieve healthcare supply-related barriers and achieve the goal of universal ART access.