WHO declares Hepatitis D virus as "carcinogenic": What does this mean amidst rising liver diseases

The World Health Organization (WHO) and the International Agency for Research on Cancer (IARC) have classified the hepatitis D virus (HDV) as carcinogenic to humans. HDV has joined hepatitis B and C on the list of cancer-causing agents. On Monday, during the occasion of World Hepatitis Day, July 28, 2025, WHO urged governments and partners to accelerate efforts to eliminate viral hepatitis as a public health threat and reduce liver cancer deaths. Hepatitis (B, C, and, D) affects over 300 million people globally and claims 1.3 million lives each year, mainly from liver cirrhosis and cancer."Every 30 seconds, someone dies from a hepatitis-related severe liver disease or liver cancer. Yet we have the tools to stop hepatitis,” Dr Tedros Adhanom Ghebreyesus, WHO Director-General, said in a statement. Viral hepatitis (types A, B, C, D, and E), is the major cause of acute liver infection. Hepatitis B, C, and D can result in chronic infections that increase the risk of liver cirrhosis, liver failure, or liver cancer. Yet most people with hepatitis don’t know they’re infected.

What is Hepatitis D

Hepatitis D, also known as delta hepatitis, is a rare but severe liver infection caused by the Hepatitis D virus. It is rare because it can only infect people who are already infected with the hepatitis B virus (HBV). HDV can only occur as a co-infection or superinfection in people who are HBV-positive.The International Agency for Research on Cancer (IARC) has recently classified hepatitis D as carcinogenic to humans. Compared to HBV alone, HDV has a two- to six-fold higher risk of liver cancer, making it a serious infection. By classifying HDV as carcinogenic, the health organizations are hoping to raise awareness, improve screening, and expand access to new treatments for hepatitis D across the globe.“WHO has published guidelines on testing and diagnosis of Hepatitis B and D in 2024, and is actively following the clinical outcomes from innovative treatments for hepatitis D,” Dr Meg Doherty, incoming Director of Science for Health at WHO, said.Oral medication can treat Hepatitis C within 2 to 3 months, while effectively controlling hepatitis B with lifelong treatment. The treatment options for HDV, on the other hand, are still developing. Major progress in preventing liver cirrhosis and cancer deaths depends on further steps in managing the global burden such as vaccination, testing, harm reduction, and treatment.In a 2024 report, the WHO had said that India had over 3.5 crore cases of viral hepatitis, including 2.98 crore hepatitis B cases, in 2022, which accounts for 11.6% of the total disease burden globally that year.Liver diseases are on the rise globally, and HDV being classified as carcinogenic has raised concerns. It adds to the urgency to address this growing crisis, as co-infections exacerbate liver damage and cancer risk. Regular screening and early detection of co-infections, including HDV, will be crucial in reducing the global burden of viral hepatitis