Hepatitis D Virus as Carcinogenic

WHO–IARC classifies Hepatitis D virus as carcinogenic, raising urgency for HBV vaccination, universal testing, and stronger hepatitis control measures.

WHO–IARC Classifies Hepatitis D Virus as Carcinogenic

Syllabus: Health – Communicable Diseases, Science & Technology in Medicine (UPSC Prelims)
Source: Business Standard

Context:

The World Health Organization (WHO) and the International Agency for Research on Cancer (IARC) have officially classified Hepatitis D virus (HDV) as carcinogenic to humans, placing it in Group 1 alongside Hepatitis B and C — proven causes of liver cancer.

What is Hepatitis D Virus (HDV)?

A blood-borne virus that requires Hepatitis B virus (HBV) to replicate.
Occurs as:
- Co-infection: Contracted simultaneously with HBV.
- Superinfection: Acquired after existing HBV infection.
Cannot survive independently without HBV.

Global and Regional Burden

Affects ~12 million people globally (~5% of chronic HBV carriers).
High prevalence in Asia, Africa, and the Amazon Basin.
High-risk groups: injection drug users, dialysis patients, people with unsafe medical practices.

Symptoms and Transmission

Symptoms: Fatigue, jaundice, nausea, abdominal pain, dark urine — often misdiagnosed.
Transmission:
- Infected blood
- Unprotected sex
- Unsafe injections
- Mother-to-child transmission

Why HDV is Cancer-Causing

Increased Cancer Risk: Co-infection with HBV raises liver cancer risk by 2–6 times.
Faster Liver Damage: 75% develop cirrhosis within 15 years (vs. 50% in HBV-only cases).
Aggressive Disease: Rapid fibrosis and liver failure, often in younger populations.
Mechanism: HDV hijacks HBV’s replication machinery, amplifying viral load and cancer risk.

Current Treatment & Prevention

No HDV-specific vaccine — HBV vaccination is the only preventive measure for both viruses.
Bulevirtide (approved in Europe) + pegylated interferon show promise.
HBV managed with lifelong antivirals.
Therapies for HDV remain limited and expensive.

WHO–IARC Reclassification: Expected Impact

Boosts funding for hepatitis prevention and treatment programmes.
Expands global surveillance and improves primary healthcare integration for hepatitis screening.
Encourages universal HDV testing for all HBV-positive individuals.
Supports WHO’s 2030 elimination targets:
- 60% of cases diagnosed
- 50% treated
- Reduce global burden to 9.8 million infections and 2.8 million deaths.