Decentralized point-of-care HBV viral load testing for HBs Ag positive pregnant women in Mali, a prospective study

Hepatitis B virus (HBV) infection remains a major public health challenge, particularly in sub‑Saharan Africa, where mother‑to‑child transmission (MTCT) is a leading cause of chronic infection. Perinatal HBV acquisition carries a high risk of chronic disease, yet prevention efforts are limited by restricted access to HBV DNA testing. Simplified point‑of‑care viral load assays, such as Xpert® HBV Viral Load, may strengthen MTCT prevention in resource‑limited settings. A cross-sectional study was conducted between June 2024 and May 2025 among pregnant woman attending antenatal care at different levels of the health system pyramid in Mali. The study sites included Referral Health Centers in Commune III of Bamako, Bla, and Sikasso, as well as Community Health Centers in Djibouria (Kéniéba district) and Badialan (Commune III, Bamako). Pregnant women testing positive for HBs Ag by a rapid test were enrolled. Venous blood (4 mL) was collected for HBV viral load quantification using the Xpert® assay. Samples from Bla and Sikasso were analyzed in decentralized laboratories, while others were tested at the central UCRC laboratory. Among 2,952 pregnant women screened, 205 were HBsAg positive (prevalence of 6.9%). After excluding hemolyzed samples, 191 women underwent HBV viral load testing. Overall, 64.0% had detectable HBV DNA; among these, 69.9% had viral loads < 2,000 IU/mL, while 5.7% had levels > 200,000 IU/mL. Viral load was not associated with maternal age or gestational age but was significantly associated with antiviral treatment status (p < 0.001). Same-day results were more frequent in decentralized laboratories with on-site GeneXpert testing than in the central laboratory (23.5% vs. 4.4%). However, in both settings, most results were returned after more than four days, with a significant difference in turnaround time distribution (p < 0.001). HBV infection remains highly endemic among pregnant women in Mali, with a meaningful proportion presenting with high viral loads associated with increased risk of mother-to-child transmission. Decentralized Xpert® HBV viral load testing is feasible and improves turnaround time compared with centralized testing, although operational challenges persist. Expanding decentralized access and addressing system-level barriers could enhance timely clinical decision-making and strengthen mother-to-child transmission (MTCT) prevention. HBV remains highly endemic among pregnant women in Mali, and decentralized HBV viral load testing using the Xpert® platform is feasible and improves result turnaround time, enabling more timely identification and management of women at high risk of mother-to-child transmission.