Seroepidemiology of human herpesvirus-6 in pregnant women from different parts of the world.

The prevalence of HHV-6 IgG was studied in 11 different countries across several continents: Morocco, Burkina-Faso, Congo, Ivory Coast, Mali, Niger, Senegal, Togo, Ecuador, Martinique, and France. The study group consisted of 550 pregnant women, representative of the general adult population in each country. Antibodies were detected by immunofluorescence assay on HSB-2 cells infected with HHV-6. Each serum was tested at nine dilutions (1:20 to 1:5,120), sera greater than or equal to 20 being considered positive. For the negative antigen control, we used mock-infected HSB-2 cells. Great differences were seen between separate areas: Morocco showed both low prevalence (20%) and a low geometric mean titer (12), whereas sub-Saharan Africa displayed high prevalences (60% to 90%) and variable geometric mean titers (34 to 229). This study revealed a prevalence of 92% for Ecuador, significantly higher than the prevalence for Martinique (50%), yet both countries had very low antibody titers compared with those found in Africa. The prevalence in France (76%) was similar to previous results from other European countries.