Hepatitis D was discovered in 1977 by Rizzetto and his team of researchers inadvertently in livers infected with hepatitis B.
- Hepatitis D is the smallest pathogenic virus known to affect humans.
- It only infects people already infected with hepatitis B.
- Benin, Gabon, Mauritania, Nauru (in Oceania) and Mongolia are countries where the prevalence of VHD is high. It is less than 1% in North America and Northern Europe and more than 2% in some countries in sub-Saharan Africa, Central Asia and Eastern Europe.
According to a publication in the JAMA, hepatitis D virus (HDV) affects 12 to 72 million people worldwide. It only infects people who also carry the hepatitis B virus. Infection can occur as an acute co-infection with HBV when the two viruses are acquired together or as a superinfection when HDV infects a person with chronic hepatitis infection. B. Acute co-infection of both hepatitis is followed by elimination of both viruses in approximately 95% of patients, while more than 90% of HDV superinfections result in chronic infection by both hepatitis. Compared to chronic hepatitis B alone, chronic hepatitis D is associated with a more rapid progression to cirrhosis and higher mortality once cirrhosis is established.
How is hepatitis D diagnosed?
HDV infection is transmitted by skin lesion (injectable drugs, tattooing, etc.) by percutaneous exposure or by contact with infected blood or blood products. Hepatitis D is diagnosed by a blood test. The presence of hepatitis D virus antibodies indicates current or past infection, while the presence of hepatitis D virus RNA indicates current infection.
Hepatitis D is dependent on hepatitis B
Hepatitis D testing should be performed in all HB-positive individuals, especially those with unexplained hepatitis flares, active hepatitis, or rapid progression to cirrhosis. Hepatitis D should also be tested for in people living in or who have emigrated from a country where hepatitis D is common and in those at increased risk of exposure (for example, people with advanced liver disease and in people at high risk of infection, such as people who inject drugs and sex workers, men who have sex with men, hemodialysis patients, and people co-infected with HIV).
VHD: is there a vaccine?
There is no vaccine to prevent HDV infection, but vaccination against hepatitis B also protects against hepatitis D.
How can hepatitis D be prevented?
Vaccination against HBV is the most effective way to prevent hepatitis D. People with hepatitis D should take normal precautions, such as avoiding sharing razors and toothbrushes within the household. Family members of people with hepatitis D should be screened for hepatitis B and vaccinated against HBV if they are likely to be vaccinated.
The only possible therapies against hepatitis D aim to deprive the virus of the functions necessary for its life cycle which is ensured by HBV or by the host. According to the WHO : “The generally recommended treatment for HDV infection is pegylated alpha interferon (…) Bulevirtide is one of the promising new treatments against hepatitis D.“
Hepatitis D cases all over the world
The most common routes of infection in low- and middle-income countries are exposure to contaminated needles, unsterilized equipment during medical procedures, and sharing of contaminated household items, such as toothbrushes. . Approximately 70% of new HDV transmissions in developed countries are associated with injection drug use and unsafe sexual practices.