Residual risk of hepatitis B virus (HBV) mother-to-child transmission and gaps in HBV care cascades among pregnant women in The Gambia: the INFANT-B study

Abstract

Background: Elimination of hepatitis B virus (HBV) is not achievable without prevention of mother-to-child transmission (PMTCT). In its 2024 guidelines, the WHO guidelines identified major research gaps on HBV MTCT in Africa.

Aims: Following the implementation of an antenatal HBV screening in The Gambia, we estimated the rate of HBV MTCT and the peripartum care cascade among pregnant women.

Methods: multicentre, non-randomised interventional study in Gambian antenatal clinics. Following mass and individual sensitisation, consecutive pregnant women were offered HBV testing and blood collection for further retrospective HBV MTCT risk assessment. HBsAg-positive mothers and their babies were prospectively followed up to 6-9 months post-partum. The primary endpoint was the rate of HBV MTCT defined by the proportion of HBsAg-positive babies.

Results: Between 2019 and 2022, 9,697/9,708 (99.9%) pregnant women accepted HBV screening; 449/9,697 tested positive (HBsAg prevalence:4.6% (95%CI:4.2-5.1)). Among 428 traceable live births, 216 (49.6%) babies were successfully tested for HBV; 6/216 were positive giving a 2.8% rate of MTCT (1.1-6.2). Major gaps in the HBV prevention and care services were identified: 64% of newborns did not receive HBV birth-dose vaccine, 25% of HBsAg-positive pregnant women refused to give blood for further risk stratification, and 62% were not linked to care after delivery. A small proportion (<2%) of women were eligible for postpartum treatment according to the 2017 EASL and 2024 WHO guidelines.

Conclusion: In The Gambia, the residual risk of HBV MTCT exceeds the elimination absolute target. Strategies to improve the peripartum and post-partum HBV care cascade are urgently needed.

Keywords: Africa; Hepatitis B; cascade of care; mother-to-child transmission.