By Mohammed Abdulkadir, MA, MPH, Hepatitis B Coalition of Washington
Each May, during Hepatitis Awareness Month, we are reminded that some of the most serious public health threats are also the least talked about. Hepatitis B is one of them—and Hepatitis D, also known as Hepatitis Delta, is a lesserknown but far more dangerous virus that depends on hepatitis B, may be the most overlooked of all.
Globally, about 300 million people are living with chronic Hepatitis B, including about 2.4 million people in the United States. Despite these staggering numbers, Hepatitis B often goes undiagnosed for years because many people experience no symptoms early on. By the time fatigue, jaundice, abdominal pain, or nausea appear, the liver may already be severely damaged. Chronic Hepatitis B is a leading cause of cirrhosis and liver cancer, conditions that are often preventable with early diagnosis and care. In fact, liver cancer is one of the fastestrising causes of cancer deaths in the U.S., and Hepatitis B is a major driver.
This is not happening by chance!
In the United States, Hepatitis B disproportionately affects people born in parts of Asia, Africa, and the Pacific Islands, not because of biology or behavior, but because of longstanding inequities in global vaccination access. Many people from these communities acquired Hepatitis B at birth, before vaccines were widely available. Immigrating to the U.S. does not erase that risk—especially when language barriers, limited access to care, and stigma stand in the way of testing and treatment.
But Hepatitis B does not discriminate. It can be transmitted through or drugpreparation equipment, sexual contact, sharing needles or any exposure to infected blood or body fluids. Anyone who is unvaccinated is vulnerable.
What many people—and too many clinicians—still don’t realize is that Hepatitis B can open the door to something far worse: Hepatitis D.
Hepatitis D is unique. It cannot exist without Hepatitis B. The Hepatitis D virus hijacks the Hepatitis B virus to survive and replicate. That means only people living with Hepatitis B can get Hepatitis D—but when they do, the consequences can be devastating.
There are two ways Hepatitis D infects someone: either at the same time as Hepatitis B, or later as a “superinfection” in someone who already has chronic Hepatitis B. That second scenario is especially dangerous. Hepatitis D is widely recognized as the most severe form of viral hepatitis, accelerating liver damage and dramatically increasing the risk of liver failure and cancer.
According to the World Health Organization (WHO), Hepatitis D virus affects nearly 5%—an estimated 12 million—of people globally who have a chronic hepatitis B virus infection. In the U.S., recent studies suggest that around 3-5% of people with Hepatitis B are infected with Hepatitis D—but the true number is likely higher because routine screening is still not the norm.
This gap matters. Many people with Hepatitis D feel fine until their disease has rapidly progressed. Without testing, providers may assume worsening liver disease is due to Hepatitis B alone, missing the chance for closer monitoring, specialist referral, or emerging treatments.
Here’s the most important point: Hepatitis D is entirely preventable!
Because Hepatitis D can only infect someone who has Hepatitis B, the Hepatitis B vaccine also prevents Hepatitis D. Since 1982, this vaccine has safely protected millions of people for life. Yet too many adults—especially those born before universal childhood vaccination—remain unvaccinated or unsure of their status.
There is also reason for hope for those already living with these viruses. While treatment options for Hepatitis D were limited for decades, new therapies have recently been approved in parts of the world, and additional treatments are in advanced clinical trials in the United States. Awareness, testing, and linkage to care are more important than ever.
This is where local action makes a difference!
The Hepatitis B Coalition of Washington, coordinated by International Community Health Services, has worked for three decades to educate communities, promote testing and vaccination, and improve access to care. Through partnerships with clinics, community organizations, and publichealth agencies, we are tackling Hepatitis B—and raising urgently needed awareness about Hepatitis D—across Washington state.
As Hepatitis Awareness Month reminds us, silence is one of the greatest threats to public health. Testing saves lives. Vaccination prevents disease. And knowledge empowers communities. If you don’t know your Hepatitis B status, ask your doctor to test you. If you haven’t been vaccinated, ask for the vaccine. And if you are living with Hepatitis B, ask whether you should be tested for Hepatitis D. These simple steps can mean the difference between life and irreversible liver disease.
Hepatitis B is preventable. Hepatitis D is preventable. And together, with awareness and action, we can stop both!
