Of the 5 types of hepatitis, which is the rarest?

Hepatitis D is considered the rarest type of hepatitis among the five known types (A, B, C, D, and E) primarily because it can only occur in individuals who are already infected with hepatitis B. This dependency on the presence of hepatitis B to replicate and cause disease limits its prevalence. Hepatitis D is an example of a satellite virus, meaning it cannot exist independently and relies on another virus for its transmission and replication. Consequently, since hepatitis B is more common, the co-infection with hepatitis D is less frequent.

In contrast, hepatitis A and B are more widely recognized and commonly encountered in various geographic regions, while hepatitis C, although it varies in incidence, also has a larger population affected by it compared to hepatitis D. Hepatitis E, while not as prevalent in some areas, is still more commonly reported than hepatitis D. Thus, the rarity of hepatitis D stems from its unique requirement for hepatitis B for infection and propagation.