there's all kinds of viral diseases like Hepadnaviridae which is Hepatitis B or Paramyxoviridae which is the measles virus or mumps

The scientific name for Hepatitis B virus is Hepatitis B virus (HBV). It is a member of the family Hepadnaviridae.

Hepatitis B is caused by the Hepatitis B virus (HBV).

Hepatitis C is caused by the Hepatitis C virus (HCV).

Hepatitis B virus belongs to the family Hepadnaviridae, and the genus Orthohepadnavirus.

Hepatitis C virus belongs to the family Flaviviridae, and the genus Hepacivirus.

Hepadnaviruses are very very dangerous like other hazardous viruses. If untreated or remain free during an infection these may eventually lead to complicated conditions that may even cause death. These complications are Hepatocellular carcinoma and Liver cirrhosis that ends on liver chronic failure and at last death.

No. Though measles contains an RNA genome like retroviruses, it does not have the distinctive enzyme reverse transcriptase, and therefore does not change its genome to DNA before transcription.