Which type of hepatitis is considered the most rare?

Hepatitis D is considered the most rare type of hepatitis mainly because it only occurs in people who are already infected with Hepatitis B. This dependency on Hepatitis B for its existence limits its prevalence. Hepatitis D is a defective virus that cannot replicate on its own and requires the presence of Hepatitis B to form a complete infectious particle.

In comparison, Hepatitis A and Hepatitis E are typically transmitted through contaminated food and water, making them more common in certain areas. Hepatitis C, while also common, can be spread through blood and is widespread globally. Since Hepatitis D's existence hinges on the presence of another virus, it is significantly less prevalent, making it the rarest type among the hepatitis viruses.