Cytomegalovirus and Epstein-Barr virus coinfection in three toddlers with prolonged illnesses.

Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) usually cause primary and latent infections during childhood; thus, coinfection with these viruses occurs occasionally in children. However, its clinical impact has not been established, and may be underestimated. Three cases of coinfection involving these two viruses in toddlers are described: a 14-month-old male with infectious mononucleosis, an 18-month-old female with hemophagocytic lymphohistiocytosis, and a 13-month-old female with acute hepatitis. All three patients had prolonged illnesses. Serial serological testing and quantitation of viral DNA for CMV and EBV using peripheral blood from the patients suggested primary infections with both viruses. In all three cases, the viral load of EBV and CMV in the early stage of disease exceeded 6.4 x 10(3) and 8.8 x 10(2) copies/ml of whole blood, respectively, suggesting that the viruses were associated with the clinical condition. Recognizing that coinfection with these viruses may modulate the clinical course of disease is important.