Competitive ELISA for detection of HHV-6 antibody: seroprevalence in a danish population.

A competitive HHV-6 enzyme-linked immunosorbent assay (ELISA) was established, utilizing HHV-6 rabbit polyclonal antibodies and HHV-6 cellular antigen. In total, 285 sera from Danish children aged 1-6 years were screened for HHV-6 antibodies. The lowest seropositive rate, 78% was found in the youngest age group from 1 year to 15 months. All 120 (100%) children aged 3 years and above were seropositive. The ELISA was compared with indirect immunofluorescence assay (IFA) using a group of 83 serum samples from 65 Danish patients (aged 4 weeks to 72 years). All but one of the sera (100% of patients) were positive in the ELISA, but only 71% of sera (65% of patients) were positive with both assays. The ELISA detected one seroconversion in a baby, which was not detected by IFA. The ELISA was found to be more sensitive than IFA.