Viral Hepatitis

病毒性肝炎

Evidence-backed information EN 5/7 applicable sections · ZH 5/7 applicable sections Updated Oct 23, 2026

Viral hepatitis is a major global public-health threat, causing an estimated 1.3 million deaths annually and affecting roughly 304 million people with chronic hepatitis B or C infection worldwide ^[1]. The five principal viral strains (A, B, C, D, E) differ in transmission, severity, and prevention, with types B and C driving most chronic disease and mortality ^[1]^[2]. Sustained scale-up of vaccination, testing, and treatment is needed to meet global elimination targets by 2030 ^[1]^[3].

Read the full clinical and epidemiological profile 6

Definition

Viral hepatitis denotes inflammation of the liver induced by hepatotropic viruses, most importantly types A, B, C, D, and E, though non-infectious agents may also cause hepatitis ^[1]^[2]. These viral strains are the leading worldwide cause of hepatitis and are distinguished by differing modes of spread, disease chronicity, and prevention approaches ^[2].

Clinical features

Acute viral hepatitis may be asymptomatic or present with jaundice, dark urine, severe fatigue, nausea, vomiting, and abdominal pain ^[2]. The condition can resolve spontaneously or progress to fibrosis, cirrhosis, or liver cancer, with types B and C most often leading to chronic disease ^[2]. Elevated liver chemistries such as ALT and AST support hepatocellular injury assessment in affected patients ^[4].

Epidemiology

Viral hepatitis causes approximately 1.3 million deaths per year and ranks among the foremost infectious disease killers globally ^[1]. An estimated 304 million individuals live with hepatitis B or C, yet most lack access to testing and treatment ^[1]. Types B and C collectively represent the most common cause of liver cirrhosis, liver cancer, and hepatitis-related mortality, while all five types carry substantial outbreak and epidemic potential ^[1]^[2].

Transmission

Hepatitis A and E are principally transmitted through ingestion of contaminated food or water ^[2]. Hepatitis B, C, and D are generally spread via parenteral exposure to infected body fluids, including contaminated blood or medical procedures, and for hepatitis B also through mother-to-child transmission at birth, family contact, and sexual contact ^[2]. Mother-to-child transmission of HBV and HCV is a key driver of chronic infection burden ^[5].

Prevention

Expansion of hepatitis B vaccination alongside improved access to prevention, testing, and treatment for hepatitis B and C forms the core of prevention strategy ^[1]. Public education campaigns to raise awareness and reduce transmission are recommended, and vaccines exist to prevent hepatitis A, B, and E ^[1]^[3]. Preventing mother-to-child transmission is essential to lowering the global chronic hepatitis burden, requiring approaches adapted to local health-care and socioeconomic constraints ^[5].

References

1 World Health Organization. Hepatitis [Internet]. cited 1 Sept 2026. Available from: https://www.who.int/health-topics/hepatitis
2 World Health Organization. Hepatitis [Internet]. cited 1 Sept 2026. Available from: https://www.who.int/news-room/questions-and-answers/item/hepatitis
3 Odenwald MA et al. Viral hepatitis: Past, present, and future. World J Gastroenterol. 2022 Apr 14. PMID: 35582678. doi: 10.3748/wjg.v28.i14.1405. PubMed: https://pubmed.ncbi.nlm.nih.gov/35582678/
4 Kwo PY et al. ACG Clinical Guideline: Evaluation of Abnormal Liver Chemistries. Am J Gastroenterol. 2017 Jan. PMID: 27995906. doi: 10.1038/ajg.2016.517. PubMed: https://pubmed.ncbi.nlm.nih.gov/27995906/
5 Terrault NA et al. Viral hepatitis and pregnancy. Nat Rev Gastroenterol Hepatol. 2021 Feb. PMID: 33046891. doi: 10.1038/s41575-020-00361-w. PubMed: https://pubmed.ncbi.nlm.nih.gov/33046891/