IgG antibodies to human herpesvirus-6 in children and adults and in primary Epstein-Barr virus infections and cytomegalovirus infections [corrected].

Antibody titers against human herpesvirus-6 (HHV-6) were determined in 80 healthy adults and 100 children and teenagers from Sweden to gain information on the role of the virus and its epidemiology. Based on a positive immunofluorescence titer of 1:10 and above, about 85% of the adults and children were seropositive with 60% seropositivity of children below age one year. Titers were generally higher in patients with simultaneous EBV or CMV infection, yet crossreactivity appeared essentially no problem. HHV-6 thus is ubiquitous like other herpesviruses. Primary infection seems to occur early in life, and reactivation or delayed primary infection may be associated with a variety of disorders.