Abstract
The article discusses the replication of HBV DNA in hepatocytes when the patients catch HBV and HDV co-infection. We tried to study the molecular interactions of HDV and HBV viruses as many aspects of the pathogenesis of Delta hepatitis remain undiscovered. Different experiments by several scientists were reviewed and on the basis of shortfalls, we decided to examine patients with HCVD, in whom HBV DNA was not detected in the blood during PCR examination.