Protocol for A Systematic Review and Meta-Analysis on the Evolution of Hepatitis D Virus (HDV) Seroprevalence among HBsAg-Positive Individuals in Cameroon over Four Decades (1986–2025)

Hepatitis D Virus (HDV) is a defective RNA satellite virus that requires Hepatitis B Virus (HBV) surface antigen (HBsAg) for virion assembly, envelope propagation, and transmission. HDV co-infection or super-infection represents the most severe form of chronic viral hepatitis, accelerating progression to liver cirrhosis, hepatic decompensation, and hepatocellular carcinoma (HCC). Cameroon is recognized as a highly endemic region for HBV and HDV within West-Central Africa. However, existing epidemiological reports vary substantially across regions, sub-populations, and historical periods. To date, no comprehensive, long-term quantitative synthesis has evaluated the temporal evolution of HDV seroprevalence in Cameroon across the past four decades (1986–2025). Primary Objectives: ·         Pooled Seroprevalence: To estimate the pooled overall HDV seroprevalence (anti-HDV antibodies and/or HDV RNA) among HBsAg-positive individuals in Cameroon. ·         Temporal Trends: To evaluate chronological trends in HDV seroprevalence across four distinct decades (1986–1995, 1996–2005, 2006–2015, and 2016–2025). ·         Heterogeneity & Subgroups: To quantify and explore sources of inter-study heterogeneity across geographical regions, study populations, and diagnostic methodologies. ·         Risk of Bias & Robustness: To evaluate potential publication bias and assess the robustness of pooled estimates via sensitivity analyses.