Viral Hepatitis B, C and D (Parenteral Transmission).

Abstract: Viral hepatitis B, C, and D are major global health problems characterized by chronic liver infection and significant morbidity and mortality. These hepatotropic viruses are primarily transmitted through parenteral routes, including contaminated blood products, unsafe injections, intravenous drug use, and perinatal exposure. Hepatitis B virus (HBV) and hepatitis C virus (HCV) are the most prevalent causes of chronic hepatitis, cirrhosis, and hepatocellular carcinoma worldwide, while hepatitis D virus (HDV) is a defective virus that requires HBV for replication, leading to more severe disease outcomes. Early diagnosis through serological and molecular markers is essential for monitoring disease severity and transmission risk. Effective vaccines exist for HBV, which also prevents HDV infection; however, no vaccine is currently available for HCV. Antiviral therapies, including direct-acting antivirals (DAAs) for HCV and nucleos(t)ide analogs for HBV, have significantly improved treatment outcomes. Strengthening screening programs, improving blood safety, and increasing vaccination coverage remain critical strategies to reduce the burden of these parenterally transmitted hepatitis viruses.