Cytomegalovirus in the mononucleosis syndrome in children.

In 7 children aged 18 months to 7 years isolated from a group of 128 children with infectious mononucleosis the cytomegalovirus infection was found. Infection was diagnosed by determination of antibodies against immediate early and late CMV antigen by means of the ELISA test. Besides that, antibodies were determined against the capsid antigen and early antigen of EB virus by the method of indirect immunofluorescence. In four children only cytomegalovirus infection was found and three had a mixed infection with both viruses and the diagnosis in these cases was: infectious mononucleosis (due to EBV) with coexistent or following CMV infection. In the sera of two children with cytomegalovirus mononucleosis changes were observed in the antibodies against EBV which is explained as a result of interactions between CMV and EBV in the organism of the host.