WHO Classifies Hepatitis D as Carcinogenic: A Wake-Up Call in Global Hepatitis Fight
WHO classifies hepatitis D as carcinogenic, joining hepatitis B and C. This reclassification marks a major step in global efforts to eliminate viral hepatitis.
Introduction: A Silent Killer Gains Urgency
On World Hepatitis Day 2025, the World Health Organization (WHO) delivered a crucial public health alert: hepatitis D has officially been classified as carcinogenic to humans. The announcement by the International Agency for Research on Cancer (IARC) positions hepatitis D alongside hepatitis B and C — well-known causes of liver cancer — intensifying the global call for urgent hepatitis elimination efforts.
Context & Background: Why Hepatitis Matters
Viral hepatitis remains one of the deadliest infectious diseases worldwide. Types A, B, C, D, and E infect millions, but it’s hepatitis B, C, and D that lead to chronic liver disease — including cirrhosis, liver failure, and cancer. Despite this, hepatitis remains underdiagnosed and undertreated. Over 300 million people are currently living with chronic hepatitis B, C, or D infections, with more than 1.3 million deaths reported annually.
World Hepatitis Day, observed every July 28, aims to increase awareness and push for the elimination of viral hepatitis as a public health threat by 2030 — a goal outlined in WHO’s Global Health Sector Strategy. This year’s theme, “Hepatitis Can’t Wait,” couldn’t be more fitting.
Main Development: Hepatitis D Declared Carcinogenic
In a landmark move, the IARC has classified hepatitis D virus (HDV) as carcinogenic to humans, placing it in the same risk category as hepatitis B and C. This means there is now sufficient scientific evidence linking HDV infection to liver cancer in humans.
Unlike other hepatitis viruses, HDV cannot infect people on its own — it relies entirely on the presence of hepatitis B virus (HBV) to replicate. Individuals co-infected with HBV and HDV face a 2- to 6-fold higher risk of developing hepatocellular carcinoma (primary liver cancer) compared to those infected with HBV alone.
This dual infection also accelerates liver damage more aggressively, often resulting in faster progression to cirrhosis and liver failure.
Expert Insight: A Turning Point in Hepatitis Control
Dr. Meg Doherty, Director of WHO’s Global HIV, Hepatitis, and STIs Programmes, called the classification a “crucial turning point in hepatitis policy.”
“We have long underestimated hepatitis D. This reclassification should prompt urgent action from global health stakeholders to prioritize diagnosis, treatment, and vaccination strategies,” she stated in Geneva.
Medical experts agree. Dr. Paul Farmer, hepatology researcher at the Global Liver Institute, noted:
“HDV-related liver disease is the most severe form of viral hepatitis, yet it remains largely hidden. Improved access to testing and targeted therapies is now more important than ever.”
Impact & Implications: Who’s at Risk?
The new classification has widespread implications, especially for those already living with hepatitis B. Because HDV requires HBV to replicate, it affects only a subset of the HBV-infected population — estimated to be around 12 to 20 million people globally, concentrated in parts of Central Asia, Africa, Eastern Europe, and the Amazon Basin.
Hepatitis D is primarily blood-borne, spreading through:
- Shared needles or drug injection equipment
- Unscreened blood transfusions
- Unsafe medical practices
- Sexual contact with an infected person
Symptoms of co-infection often appear 3–7 weeks after exposure and may include fever, nausea, jaundice, dark urine, and even liver failure. If untreated, HDV can lead to chronic hepatitis, cirrhosis, and cancer.
The only preventive measure currently available is vaccination against hepatitis B, which indirectly prevents HDV infection as well. Yet global vaccination rates vary, and adult immunization remains a challenge in many countries.
Looking Ahead: What Needs to Be Done
The WHO is urging governments and healthcare systems to:
- Scale up HBV vaccination to prevent new HDV cases
- Expand HDV screening among people already diagnosed with hepatitis B
- Invest in research and access to newer antiviral therapies targeting HDV
- Strengthen health infrastructure to identify and treat chronic liver disease earlier
New treatment options are on the horizon, including antiviral agents like bulevirtide, already conditionally approved in parts of Europe. But access remains limited, especially in low- and middle-income countries.
Global health organizations are calling for integrated care models, where hepatitis diagnosis, counseling, and treatment are offered under a unified system — particularly in high-burden areas.
Conclusion: From Awareness to Action
The reclassification of hepatitis D as carcinogenic serves as a sobering reminder of the persistent danger posed by viral hepatitis. While hepatitis B and C have long been known cancer threats, this new recognition of HDV changes the stakes — both scientifically and politically.
The path forward must focus on widespread HBV vaccination, improved diagnostics, equitable access to care, and continued global commitment to hepatitis elimination by 2030. As WHO officials warned on World Hepatitis Day, every 30 seconds, someone dies of a hepatitis-related disease. The time to act is now — because hepatitis can’t wait.
Disclaimer: This article is for informational purposes only. It does not constitute medical advice. Please consult a healthcare professional for diagnosis or treatment of hepatitis or related liver conditions.