Therefore, it can be isolated from saliva, tears, breast milk, semen, cervical secretions, blood products and urine. HCMV infection may be either latent (non-productive), lytic (productive), asymptomatic or symptomatic. 4 CMV pathogenicityResearch to validate the correlation of CMV infection with age denoted the presence of three periods of increased incidence of infections: early childhood, adolescence and the reproductive period. The virus can be present in different secretions of an infected person, such as discharge from the oropharynx, urine, vagina, semen, milk, and blood components. The virus spreads by direct contact with an infected person, vertically from mother to fetus, and parenteral, i.e. blood transfusions, organ or bone marrow transplants. 15

Introduction: Biliary atresia (BA) is a disease characterized by a biliary obstruction of unknown origin. Viral agents have been proposed in the aetiology of BA such as cytomegalovirus (CMV). This virus also considered as a one of agents that can infect the liver and cause hepatitis. The aim of this study was to determine the role of CMV in children with both chronic hepatitis (negative for hepatitis B and C) and have biliary atresia in the same time. Material and Methods: A retrospective study done on 13 liver tissue paraffin blocks of children with chronic hepatitis (negative for hepatitis B and C) and biliary atresia (extra and intra). The diagnosis was based on the presence of HCMV protein (pp65) by using immunohistochemistry. Results: Immunohistochemistry for pp65 showed the liver tissue blocks were positive for 10 cases (76.9%).The mild inflammation and moderate fibrosis were the highest among the cases. Conclusion: CMV is one of the important viruses that can causes hepatitis in infants (whom are negative for hepatitis B and C), also this virus has significant role in pathogenesis of biliary atresia.