Facts and Figures
In the United States HDV affects approximately 5% of patients (less than 200,000 patients) co-infected with the hepatitis B virus. While uncommon in the United States, HDV co-infection is more common in parts of the world such as China, Russia, Middle East, Mongolia, Romania, Georgia, Turkey, Pakistan, Africa, and the Amazonian river basin. Globally HDV is estimated to affect 15-20 million people.
The risk of progression to cirrhosis, including the risk of liver cancer, liver transplant, and death is in the 70% range, when patients have chronic hepatitis delta co-infection along with chronic hepatitis B.
There are at least 8 different types of HDV called “genotypes,” which are associated with distinct disease progression. In general, a more severe disease occurs in genotype 1 and 3, and a milder disease in genotype 2. Although a single genotype tends to dominate in an infected person, multiple genotypes can occur in those at high risk for repeated exposure to the virus.
Prevalence and Genotypes of Hepatitis D Around the World
Source: Eiger Biopharmaceuticals
- Genotype 1– most common and found worldwide, especially Europe, the Middle East, North America and North Africa
- Genotype 2 – found in Japan, Taiwan and Russia
- Genotype 3 – found exclusively in Amazonian region of South America
- Genotype 4 – found in Japan and Taiwan
- Genotypes 5 - 8 – identified primarily in Africa
While testing exists to determine the HDV genotype, it is not widely available or recommended due to the lack of reliability of the current tests.