Hepatitis D Virus (HDV)
| Categorization |
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| Genome: RNA Virus |
| Transmission |
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- Parenteral Transmission
- Sexually Transmitted Disease
- Mother-to-Child Transmission
| Viral Components |
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- Hepatitis D Virus is solely composed of a nucleocapsid and uses the envelope of Hepatitis B Virus (HBV) to spread from cell to cell. Consequently, HDV can only replicate if a patient is simultaneously infected with HBV.
| Sequences of Infection |
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- Co-infection: HBV and HDV may be transmitted simultaneously during a single infective event. Superinfection: HDV may be transmitted to a patient already chronically infected with HBV.
| Serology |
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- The immune system elaborates Anti-HDV IgM following infection which in many cases switches to Anti-HDV IgG later on. However, in many cases Anti-HDV IgM does not switch to IgG; therefore, the sole presence of IgM cannot distinguish between acute or chronic infection with HDV.
| Clinical Consequences |
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- Co-infection:
- Co-infection usually results in acute viral hepatitis similar to that of acute HBV infection alone. However, the presence of HDV does increasee the risk of fulminant hepatitis.
- Superinfection:
- Superinfection of HDV on a background of chronic HBV infection may appear as a flareup in chronic viral hepatitis or resemble a syndrome akin to acute viral hepatitis. However, in most cases HDV infection also enters a chronic course but increases the risk of developing cirrhosis above that of single infection with HBV.