Terminated due to financial reasons.

This prospective, multicenter, observational study will assess the prevalence of chronic hepatitis D in patients with chronic hepatitis B in Romania and evaluate the efficacy of Pegasys (peginterferon alfa-2a) in patients with chronic hepatitis D. Eligible patients treated with Pegasys according to current medical practice will be followed until 24 weeks after the end of treatment.

Inclusion Criteria:

For epidemiological part of the study:

• Adult patients >/= 18 years of age
• Positive HBsAg for at least 6 months

For the non-interventional section of the study

• Adult patients, >/= 18 years of age
• Positive HBsAg for at least 6 months
• Positive anti-delta and positive HDV RNA by PCR
• Elevated serum ALT >/= 2x ULN

Exclusion Criteria:

Patients with any of the following will not be eligible for treatment with Pegasys:

• History of neurological disease
• History of severe psychiatric disease
• Decompensated diabetes
• History of immunologically mediated disease
• History of severe cardiac disease
• History or other evidence of severe chronic pulmonary disease
• Inadequate hematologic function

Patients with chronic hepatitis B, and then those who are positive for anti-HDV Ab and treated with Pegasys