Hepatitis D

Hepatitis D is a serious liver infection that can only affect people who already have hepatitis B. It is considered the most severe form of viral hepatitis and can lead to rapid liver damage, but it can be prevented by getting vaccinated against hepatitis B.

Table of contents

• What is Hepatitis D?
• Alternative names
• Types of infection
• Affected organ
• Signs and symptoms
• What causes the disease
• How the virus spreads
• Who is at higher risk
• Possible complications
• Geographic distribution
• How doctors diagnose the disease
• Treatment options
• How to prevent infection

What is Hepatitis D?

Hepatitis D is a viral infection that causes inflammation of the liver. Inflammation is swelling that occurs when tissues of the body become injured or infected^[1]. The disease is caused by the hepatitis D virus, which is also known as hepatitis delta virus or HDV^[1].

What makes hepatitis D unique is that it cannot exist on its own. HDV is known as a “satellite virus” because it can only infect people who are also infected with the hepatitis B virus^[1]. The hepatitis D virus needs the hepatitis B virus to survive and make more copies of itself^[2]. You cannot get infected with hepatitis D on its own^[2].

A hepatitis D infection can be acute or chronic. An acute infection can come on quickly and last for a few weeks or months. Acute infections can become chronic, which means that your symptoms last longer than six months^[2]. Chronic hepatitis D is considered the most severe form of chronic viral hepatitis due to more rapid progression toward serious liver problems^[3].

Hepatitis delta, Delta hepatitis, HDV, Viral hepatitis D, Delta agent hepatitis, Delta associated hepatitis

Types of infection

People with hepatitis D can become infected with both hepatitis B and hepatitis D at the same time, or get hepatitis D after first being infected with hepatitis B^[1]. There are two main types of hepatitis D infection.

Coinfection occurs when you get infected with hepatitis D virus and hepatitis B virus at the same time^[1]. The symptoms of both infections are the same, though they might be more severe if you get them both at the same time^[2]. People with coinfection can have distinct sets of symptoms during two separate time periods because hepatitis B symptoms can occur at a different time than those of hepatitis D^[1]. Coinfection with both viruses can cause serious short-term health problems and even liver failure, but it usually does not lead to lifelong illness^[1].

Superinfection happens when people get hepatitis D after first having been infected with hepatitis B^[1]. Since superinfections happen after your initial infection with hepatitis B, your symptoms may suddenly come back or get more severe^[2]. This type of infection is more likely to result in long-term illness, including rapid development of liver scarring, liver failure, and even death^[1]. Superinfections are more likely to lead to chronic illness than coinfections^[2].

Affected organ

• Liver

Signs and symptoms

People with hepatitis D can have more severe symptoms than those who are infected with hepatitis B alone^[1]. Symptoms usually appear 3 to 7 weeks after infection with the virus^[1]. Hepatitis D can also make existing hepatitis B symptoms worse^[2].

The symptoms of hepatitis D include:

• Dark urine or clay-colored stools
• Feeling tired
• Fever
• Joint pain
• Loss of appetite
• Nausea, stomach pain, and vomiting
• Yellow skin or eyes, known as jaundice

People with superinfection usually experience rapid and severe symptoms, while people with coinfection may experience symptoms at different times as the two viruses affect the body^[1].

What causes the disease

Hepatitis D is caused by the hepatitis D virus, also called hepatitis delta or HDV^[2]. This virus has a special relationship with the hepatitis B virus. HDV uses the hepatitis B surface antigen as its envelope protein, which is why it can only infect people who also have hepatitis B^[4].

The virus needs hepatitis B virus to survive and make more copies of itself. You can only get an HDV infection while you already have a hepatitis B infection or at the same time as an initial hepatitis B infection^[2]. Interestingly, the presence of hepatitis D suppresses hepatitis B replication, although the reason for this is not well understood^[4].

The damage to the liver is caused by a combination of direct harmful effects of the virus on liver cells and damage from the body’s immune system trying to fight the infection^[4].

How the virus spreads

You can only get hepatitis D after coming into contact with the blood or body fluids of someone who is infected with the virus^[1]. The virus is transmitted in the same way as hepatitis B^[3].

Hepatitis D can spread through:

• Having sex with a person infected with the virus
• Sharing needles, syringes, or any other equipment used to prepare or inject drugs
• Birth to a person infected with the virus, although this is rare
• Contact with blood from the open sores of a person who is infected
• Needle sticks or exposures to sharp instruments
• Sharing personal items such as razors and toothbrushes that may have come in contact with the blood of a person who is infected

Hepatitis D is not spread through food or water, sharing eating utensils, breastfeeding, hugging, kissing, hand holding, coughing, or sneezing^[1].

Who is at higher risk

Risk factors for hepatitis D and hepatitis B are similar^[1]. You may be at increased risk for hepatitis D if you:

• Are already infected with hepatitis B virus
• Use or inject drugs
• Are a sex partner of someone infected with hepatitis B and hepatitis D
• Are coinfected with HIV and hepatitis B
• Are a man who has sex with men
• Are a household contact of someone with hepatitis D infection
• Work in healthcare or another field that puts you in contact with blood or blood-contaminated body fluids
• Are on hemodialysis
• Live with someone who has hepatitis B and hepatitis D

Populations that are more likely to have hepatitis B and hepatitis D coinfection include indigenous populations, recipients of hemodialysis, and people who inject drugs^[3].

Possible complications

Chronic hepatitis D infection is considered the most severe form of chronic viral hepatitis due to more rapid progression toward serious liver-related problems^[3]. Infection with both hepatitis B and hepatitis D frequently results in more severe disease than hepatitis B alone^[11].

Complications of hepatitis D include:

• Liver scarring, known as cirrhosis
• Liver failure
• Hepatocellular carcinoma, a type of liver cancer

People with chronic hepatitis D develop complications more often and more quickly than people who have chronic hepatitis B alone^[2]. Hepatitis D has recently been classified as carcinogenic to humans, just like hepatitis B and C^[3]. In combination with hepatitis B virus, hepatitis D has the highest fatality rate of all the hepatitis infections, at 20 percent^[7].

Geographic distribution

Hepatitis D is considered uncommon in the United States^[1]. Because hepatitis D is not a nationally notifiable condition, the actual number of hepatitis D cases in the United States is unknown^[1].

Hepatitis D is most common in Eastern Europe, Southern Europe, the Mediterranean region, the Middle East, West and Central Africa, East Asia, and the Amazon Basin in South America^[1]. A study conducted in collaboration with the World Health Organization estimated that hepatitis D virus affects nearly 5 percent of people globally who have a chronic infection with hepatitis B virus^[3]. This means approximately 12 million people worldwide are infected^[3].

The study identified several geographical hotspots of high prevalence of hepatitis D infection including Mongolia, the Republic of Moldova, and countries in western and central Africa^[3].

How doctors diagnose the disease

A blood test is the only way to confirm hepatitis D^[1]. Healthcare providers use blood tests to diagnose hepatitis D by looking for signs of the virus or antibodies to it in your blood^[2].

The initial screening test for hepatitis D is serum analysis for anti-HDV antibodies. If these antibodies are present, then a hepatitis D viral load test can be performed to confirm active infection^[15].

Doctors may also get imaging tests like an abdominal ultrasound or elastography to check your liver for signs of scarring^[2]. They will ask questions about your symptoms and lifestyle, then do an exam^[5].

Treatment options

There is no treatment that cures hepatitis D^[2]. Acute hepatitis D infections can go away without treatment^[2].

For chronic hepatitis D, providers may treat you with:

Peginterferon injections. This is a medication that helps your immune system fight infections^[2]. The drug prescribed most often is pegylated interferon alfa^[5]. Doctors aren’t sure how long treatment for hepatitis D should last. You may need to take this medication for a year, and if a blood test still shows a certain amount of the virus in your body, your doctor may suggest that you stay on it for up to one more year^[5]. This medication doesn’t work well for everyone and can cause many side effects, like lack of energy, weight loss, flu-like symptoms, and mental health issues like depression^[5].

Bulevirtide. This antiviral medication is approved for hepatitis D treatment in certain countries^[2]. It was approved in the European Union in 2020 and gained full market authorization in 2025^[11]. It is also approved in Switzerland, Australia, and the United Kingdom, but it is not approved for use in the United States^[2]. This is a first-in-class entry inhibitor that blocks viral entry into liver cells^[11].

Liver transplant. If your liver is severely damaged, you may need a liver transplant^[2]. Patients with evidence of decompensated liver disease or fulminant liver failure should be immediately transferred to a center capable of performing a liver transplantation^[16].

Other types of hepatitis D treatment are being tested. These include drugs that attack the virus or prevent it from latching on to hepatitis B cells that they need to survive^[5]. Several new drugs have entered various stages of development, offering hope for improved hepatitis D virus management^[14].

How to prevent infection

Although there is no hepatitis D vaccine, getting hepatitis B vaccine also protects you from hepatitis D^[1]. This is because you can only get hepatitis D if you already have hepatitis B. Hepatitis D infection can be prevented by hepatitis B immunization^[3].

If you are not already infected with hepatitis B, talk to your doctor about getting vaccinated against hepatitis B^[1].

The only way to prevent hepatitis D infection for those already infected with hepatitis B is to avoid contact with blood and body fluids^[6]. You can protect yourself by:

• Never sharing needles for drug use, ear piercing, tattooing, or any other purpose
• Using condoms when having sex
• Not sharing personal items such as razors and toothbrushes that may have come in contact with blood

The use of hepatitis B immune globulin, immune globulin, or hepatitis B vaccine will not protect people against hepatitis D in those who are already infected with hepatitis B^[6].