Cytomegalovirus is asymptomatic in majority of cases. Causative agent of infectious mononucleosis. Transmission of cytomegalovirus (CMV):
- In utero
- Early childhood (saliva, etc)
- Venereal in young adults
- Blood transfusion (1-5% rate of transmission with a CMV(-) recipient and a CMV(+) donor)
- Organ transplantation
EBV mononucleosis-Viral replication in the oropharynx, production of virus and transmission to others. Late antigen is VCA= viral capsid antigen. Antibodies induced. EBV latency: In B cells in blood. 10 Epstein-Barr nuclear antigens (EBNAs) plus the Latent Membrane Protein (LMP) are only viral antigens. EBNA-1 binds to Origin of replication and partitions circular DNA among B cell chromosomes. Reactivation from latency occurs through the BZLF protein, which activates transcription of viral genes. Eventually virus replicates, allowing transmission of the virus to seronegatives.
EBV and Lymphoproliferative Disorders: a) Burkitt's lymphoma, b) Nasopharyngeal carcinoma c) persons receiving organ transplants and immunosuppressive therapy d) Non-Hodgkin's lymphoma in HIV patients e) Clear role for EBV in Hodgkin's disease-over 50% are EBV DNA positive.