Hepatitis D can only occur where hepatitis B is present. This can be by simultaneous infection, or infection with hepatitis D in a person who is already hepatitis B positive. Co-infection with these two viruses can speed up the progression of liver disease. Transmission of hepatitis D is similar to hepatitis B, that is, through blood and sexual fluids. Successful vaccination against, or natural clearance of, hepatitis B provides indirect protection from hepatitis D. Hepatitis D is not a common infection in Australia. Over recent years, there were as few as 20 to 30 cases of hepatitis D diagnosed and notified each year.
Hepatitis E is transmitted via the faecal-oral route, as with hepatitis A. Infection generally lasts for a couple of weeks and has not been known to develop into chronic illness. Hepatitis E is not a common cause of liver disease in Australia. Over recent years, there were as few as 10 to 30 cases of hepatitis E diagnosed and notified each year.