Hepatitis B Virus (HBV) Infection in Patients at Pasteur Institute of Dakar in Senegal from 2016 to 2020: Prevalence and Seroprotection Level

Hepatitis B virus (HBV) infection is highly endemic in Senegal. Vaccination of all children against HBV was introduced in 1999 and included in Expanded Programme on Immunisation in 2005. The aim of this study was to assess the prevalence and immune status against HBV in patients received at Pasteur Institut in Dakar, Senegal. Methods: Between January 2016 and December 2020, patients aged between 1 and 96 years received laboratory were included in the study. Serum samples were analysed for HBV serology (HBs antigen: HBsAg, HBs antibody: HBsAb and HBc antibody: HBcAb) using ARCHITECT? analyser. Patients with anti-HBs antibody levels (HBsAb ≥ 10 IU/l) were considered seroprotected against HBV. Results: A total of 5629 patients were analysed with a mean age of 39 years and extremes from 1 to 96 years. The most represented age group was 31 - 45 years with 38.4%. HBsAg was present in 520 patients (9.2%) and was signed by sex and age group. Anti-HBc antibodies were found in 52.7% of patients and 1603 (28.48%) had isolated anti-HBs antibodies reflecting proportion of people vaccinated at the time of the study. However, 2143 patients (41.9%) had no seroprotection (HBsAb 10 IU/L) and 640 (12.6%) had strong seroprotection defined as HBsAb > 1000 IU/L. Conclusion: Our results show a significant presence of virus in Senegalese population and low vaccination coverage, especially in adults. Evaluation of HBsAb levels and provision of HBV booster shots should be considered for children in Senegal.