While hepatitis A, B, and C are widely recognized and discussed, there is another type of viral hepatitis that often flies under the radar: hepatitis D.
Also known as delta hepatitis, hepatitis D is a lesser-known viral liver infection caused by the hepatitis D virus (HDV).
Despite its relatively low prevalence compared to other forms of viral hepatitis, hepatitis D poses unique challenges and complications for those affected by the disease, which can culminate in severe liver damage
It often exists as a co-infection with hepatitis B, as it requires hepatitis B to replicate.
In this guide, we will delve into the basics of hepatitis D, including its transmission, symptoms, diagnosis, treatment, and prevention, to shed light on this often overlooked but important public health issue.
What is hepatitis?
Hepatitis refers to inflammation of the liver, a vital organ responsible for processing nutrients, filtering toxins, and producing bile.
It can be caused by a variety of factors, including viral infections, alcohol consumption, autoimmune diseases, and exposure to certain medications or toxins.
Viral hepatitis is primarily caused by five main types of hepatitis viruses, labeled A through E.
- Hepatitis A (HAV): transmitted through contaminated food or water, infections are usually acute and self-limiting, causing symptoms such as fatigue, nausea, jaundice, and abdominal pain.
- Hepatitis B (HBV): primarily spread through blood or bodily fluids, infections can become chronic and lead to serious liver damage if left untreated. It is preventable through vaccination and can be effectively managed with antiviral medications. Infection with hepatitis B currently has no cure.
- Hepatitis C (HCV): primarily spread through blood or bodily fluids, infections can become chronic and lead to serious liver damage if left untreated. Once considered incurable, hepatitis C can now be cured with direct-acting antiviral drugs, leading to significant improvements in treatment outcomes.
- Hepatitis D (HDV): primarily spread through blood or bodily fluids, infections can become chronic and lead to serious liver damage if left untreated. It only occurs in individuals who are already infected with hepatitis B virus and can exacerbate liver damage.
- Hepatitis E (HEV): the virus is transmitted through contaminated food or water, infections are acute, self-limiting, pose a greater risk for pregnant women, and can lead to liver failure; symptoms include fatigue, nausea, and abdominal pain.
Despite advances in prevention and treatment, viral hepatitis remains a significant global health challenge, underscoring the importance of continued efforts to raise awareness, improve access to healthcare services, and eliminate viral hepatitis as a public health threat.
Causes of Hepatitis D
Hepatitis D is caused by the hepatitis D virus (HDV), which can only infect individuals who are already infected with the hepatitis B virus (HBV).
HDV is primarily transmitted through blood-to-blood contact and other modes similar to HBV transmission:
- Injection drug use: Sharing needles, syringes, or other drug paraphernalia with an infected person increases the risk of HDV transmission.
- Sexual contact: Unprotected sexual intercourse with an infected partner can transmit HDV, particularly among individuals with HBV.
- Mother-to-child transmission: Infants born to mothers infected with HDV and HBV are at risk of acquiring the virus during childbirth.
- Healthcare-related exposures: Healthcare workers may be at risk of HDV infection through accidental needlestick injuries or exposure to contaminated blood or equipment.
- Coinfection vs. superinfection: Hepatitis D can occur as either a coinfection, where both HDV and HBV are acquired simultaneously, or as a superinfection, where HDV infects individuals already chronically infected with HBV.
Symptoms of Hepatitis D
The symptoms of hepatitis D can vary in severity and may include:
- Jaundice: yellowing of the skin and eyes due to impaired liver function.
- Fatigue: persistent tiredness and lack of energy.
- Abdominal pain: discomfort or pain in the abdominal area, often around the liver.
- Loss of appetite: a decreased desire to eat or lack of hunger.
- Nausea and vomiting: feeling sick to the stomach and vomiting.
- Dark urine: Urine may appear darker than usual due to liver dysfunction.
- Pale stools: Bowel movements may become lighter in color.
- Joint pain: Some individuals may experience joint pain or discomfort.
Diagnosis of Hepatitis D
Diagnosing hepatitis D typically involves a combination of a medical history review, a physical examination, and laboratory tests.
Key diagnostic methods include:
- Blood tests: serological tests to detect specific antibodies or viral antigens associated with hepatitis D infection, including HDV RNA testing to confirm active infection.
- Liver function tests (LFTs): blood tests to assess liver enzyme levels and overall liver function.
- HBV status: Testing for hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc) is essential to determine the HBV status of the individual and differentiate between coinfection and superinfection.
- Imaging studies: Ultrasound, CT scan, or MRI may be used to evaluate liver structure and detect any abnormalities or signs of liver damage.
Treatment and management
Treatment options for hepatitis D are limited compared to other forms of viral hepatitis, and management strategies focus on controlling symptoms and preventing complications:
- Interferon therapy: Pegylated interferon-alpha is the mainstay of treatment for hepatitis D, with the potential to suppress HDV replication and improve liver function in some patients.
- Antiviral therapy: Antiviral medications used to treat HBV, such as nucleotide analogs, are ineffective against HDV and should be used with caution.
- Liver transplantation: In cases of advanced liver disease or liver failure due to hepatitis D, liver transplantation may be considered a life-saving intervention.
- Supportive care: Adequate rest, nutrition, and hydration are essential to support liver health and overall well-being during a hepatitis D infection.
Prevention strategies
Preventing hepatitis D transmission involves similar strategies to those used for hepatitis B:
1. Vaccination against Hepatitis B
Since hepatitis D can only occur in individuals with HBV infection, vaccination against hepatitis B is the most effective way to prevent hepatitis D.
The hepatitis B vaccine is highly effective in preventing HBV infection and has been instrumental in reducing the global burden of hepatitis B-related diseases.
By vaccinating individuals against HBV, we can prevent the transmission of both HBV and HDV and reduce the risk of hepatitis D outbreaks in communities.
2. Screening and diagnosis
Early detection of HBV infection is critical for preventing hepatitis D transmission and identifying individuals who may benefit from hepatitis D treatment.
Screening for HBV infection, including testing for hepatitis B surface antigen (HBsAg) and hepatitis B core antibody (anti-HBc), should be routinely performed in high-risk populations, such as injection drug users, individuals with multiple sexual partners, healthcare workers, and pregnant women.
In regions where hepatitis D is endemic, screening for HDV RNA may also be recommended to detect active hepatitis D infection.
3. Education and awareness
Educating healthcare professionals, policymakers, and the general public about the risks and consequences of hepatitis D is essential for promoting prevention and early detection.
Public health campaigns, educational materials, and community outreach efforts can raise awareness about the importance of vaccination against hepatitis B, the link between HBV and HDV infections, and the need for regular screening and follow-up care for individuals at risk of hepatitis D.
4. Prevention of HBV transmission
Preventing HBV transmission is crucial for reducing the incidence of hepatitis D.
Public health interventions aimed at preventing HBV transmission, such as universal vaccination programs, promotion of safe injection practices, screening of blood donors, and provision of antenatal screening and vaccination for pregnant women, can indirectly contribute to the prevention of hepatitis D transmission.
