Epstein-Barr virus and infectious mononucleosis in children.

The presence of IgG antibodies to Epstein-Barr virus (EBV) has been investigated in two groups of children aged 3 to 35 months. The test group consisted of 31 children from an institution in which a high incidence of suspected infectious mononucleosis (IMN) was found. The control group comprised 54 children, aged 1 to 26 months, with noninfectious diseases. In the test group, 29 of the 31 children were positive for IgG anti-EBV antibodies in the serum, whereas only 5 children were positive in the control group. None of the children in the test group had detectable heterophile antibodies, and most of them did not show the typical symptoms of IMN. The reliability of diagnosing IMN in early childhood, by means of detection of anti-EBV serum antibody levels, is discussed.