Hepatitis B

Hepatitis B is an infection of the liver attributable to the hepatitis B virus, which may present as a short severe acute illness or as a persistent long-term infection ^[1]. It is one of several viral hepatitis strains that can lead to chronic liver disease and is distinguished from other types by its specific transmission routes and prevention needs ^[2].

The infection can be acute and short-lived or become chronic over the long term ^[1]. Chronic hepatitis B places affected persons at high risk of death from cirrhosis and liver cancer ^[1]. Clinical findings alone cannot distinguish hepatitis B from other viral hepatitides, requiring laboratory confirmation ^[1].

Hepatitis B is a major global health problem with the highest chronic infection burden in the WHO Western Pacific and African Regions, where an estimated 102 million and 64 million people are chronically infected, respectively ^[1]. In 2024 the global prevalence of chronic HBV among children under five years was about 0.6% ^[1]. The African Region, at 1.4% childhood prevalence, remains far from the 2030 elimination target of 0.1%, whereas the European and another WHO region have already surpassed it ^[1].

The virus spreads through contact with infected body fluids such as blood, vaginal fluids, semen, and saliva when open cuts or sores are present, and from mother to infant ^[1]. In highly endemic settings the predominant routes are perinatal transmission and horizontal person-to-person spread during early childhood ^[1]. Additional routes include needlestick injury, tattooing, piercing, and sharing or reusing contaminated needles ^[1].

A safe and effective hepatitis B vaccine is usually given soon after birth with booster doses a few weeks later and affords nearly 100% protection ^[1]. Universal childhood vaccination and timely birth-dose administration are essential, particularly in endemic regions with inadequate coverage ^[1]. Broader elimination strategy also relies on scale-up of vaccination and improved access to prevention and public education to reduce transmission ^[2].

1. 1 World Health Organization. Hepatitis B [Internet]. cited 23 Oct 2026. Available from: https://www.who.int/news-room/fact-sheets/detail/hepatitis-b
2. 2 World Health Organization. Hepatitis [Internet]. cited 1 Sept 2026. Available from: https://www.who.int/health-topics/hepatitis
3. 3 Ali FS et al. AGA Clinical Practice Guideline on the Prevention and Treatment of Hepatitis B Virus Reactivation in At-Risk Individuals. Gastroenterology. 2025 Feb. PMID: 39863345. doi: 10.1053/j.gastro.2024.11.008. PubMed: https://pubmed.ncbi.nlm.nih.gov/39863345/