Hepatitis B Vaccination in Senegalese Children: Coverage, Timeliness, and Sociodemographic Determinants of Non-Adherence to Immunisation Schedules (ANRS 12356 AmBASS Survey)

International audienceDetailed knowledge about hepatitis B virus (HBV) vaccination coverage and timeliness for sub-Saharan Africa is scarce. We used data from a community-based cross-sectional survey conducted in 2018–2019 in the area of Niakhar, Senegal, to estimate coverage, timeliness, and factors associated with non-adherence to the World Health Organisation-recommended vaccination schedules in children born in 2016 (year of the birth dose (BD) introduction in Senegal) and 2017–2018. Vaccination status was assessed from vaccination cards, surveillance data, and healthcare post vaccination records. Among 241 children with available data, for 2016 and 2017–2018, respectively, 31.0% and 66.8% received the BD within 24 h of birth (BD schedule), and 24.3% and 53.7% received the BD plus at least two pentavalent vaccine doses within the recommended timeframes (three-dose schedule). In logistic regression models, home birth, dry season birth, and birth in 2016 were all associated with non-adherence to the recommended BD and three-dose schedules. Living over three kilometres from the nearest healthcare post, being the firstborn, and living in an agriculturally poorer household were only associated with non-adherence to the three-dose schedule. The substantial proportion of children not vaccinated according to recommended schedules highlights the importance of considering vaccination timeliness when evaluating vaccination programme effectiveness. Outreach vaccination activities and incentives to bring children born at home to healthcare facilities within 24 h of birth, must be strengthened to improve timely HBV vaccination

Prevention and care of hepatitis B in the rural region of Fatick in Senegal : a healthcare workers' perspective using a mixed methods approach

Background In countries where hepatitis B virus (HBV) is endemic, including Senegal, the World Health Organization recommends systematic HBV screening of pregnant women and vaccination at birth to prevent mother-to-child transmission (MTCT). This study investigated healthcare workers' (HCW) knowledge and practices regarding HBV prevention and care in the rural region of Fatick in Senegal, as well as challenges they faced in implementing prevention activities related to HBV MTCT. Methods A mixed-methods survey was conducted between May-July 2017 among 112 HCW working in 15 healthcare facilities in two districts of the Fatick region using face-to-face questionnaires and semi-structured interviews. Descriptive statistics and chi-square/Mann-Whitney tests were used to analyze quantitative data, while qualitative data were analyzed thematically. Results The study population included 87 HCW in the quantitative component (83% women, median age [interquartile range, IQR] = 35 [31-40] years) and 11 in the qualitative component. A knowledge gap was observed in key areas of HBV infection: only 24, 51 and 38%, respectively, correctly reported that early HBV acquisition is associated with a high risk of developing chronic infection, that perinatal transmission is one of the main modes of HBV transmission in Senegal, and that three to four doses of HBV vaccine are required to ensure immunization in children. Despite good acceptability of systematic screening of pregnant women and vaccination at birth, only 48% of HCW mainly involved in prenatal care and 71% of those involved exclusively in vaccination routinely performed these two key interventions. HCW reported several structural barriers that may hinder their implementation: a lack of training in HBV and in counseling, poor availability of rapid diagnostic tests (RDT), high costs of both screening and treatment, a lack of adequate information on treatment options and missed opportunities for vaccination at birth. Conclusions HCW working in the Fatick region may be insufficiently trained and supported to effectively implement HBV prevention strategies. Our findings suggest an urgent need to strengthen MTCT prevention in this region, by improving HCW knowledge in key areas of HBV infection, providing RDT and antiviral treatment at low cost, and enhancing community-based interventions for the timely vaccination of newborns

Burden and impacts of chronic hepatitis B infection in rural Senegal : study protocol of a cross-sectional survey in the area of Niakhar (AmBASS ANRS 12356)

Introduction Though 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 analysis This 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 dissemination This 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