Prolonged Epstein-Barr Virus DNA Detection in a Case of Infantile Infectious Mononucleosis

Infectious mononucleosis (IM) caused by Epstein-Barr virus (EBV) is a relatively common disease in adolescents and children. There have been few reports on serial changes in EBV DNA load in IM infants, and we herein describe the precise clinical course as well as the kinetics of EBV DNA load in a case of infantile IM. An 11-month-old girl presented with persistent fever, splenomegaly, and rash and was diagnosed with IM on the basis of her EBV DNA load despite the absence of a significant increase in anti-viral capsid antigen-IgM. The result of a cytomegalovirus antigenemia assay was also positive during the acute phase, but this quickly changed to negative. However, despite the spontaneous resolution of symptoms and seroconversion, the EBV DNA load result remained positive for more than 1 year. Although the potential impact from cytomegalovirus infection is uncertain, we speculate that prolonged EBV DNA load may occur in immunocompetent infantile IM patients.