Comparison of HHV-6 antibody titers in West Africa and the Caribbean

ABSTRACT

Human herpesvirus-6 (HHV-6) infections seems to be ubiquitous early in life, but antibody responses vary by geographic area. We compared HHV-6 antibody titer in 123 West African and 122 Caribbean serum samples. A quantitative immunofluorescence assay (IFA) using antigens derived from an HSB-2 cell line was used to test for IgG HHV-6 (GS strain) antibodies. The prevalence of HHV-6 antibodies was high (98 percent) in both sites. African samples had a significantly higher geometric mean titer (GMT 697) than did Caribbean samples (GMT 99). There was no difference between males (GMT 260) and females (GMT 270) overall. Children up to and including 9 years old had significantly higher titers (GMT 483) than did all others (GMT 237), and female children tended to have higher titers than did male children. In both areas there was a trend towards highest titer at younger age, followed by a decrease in titer in the oldest age group. Environmental and host factors may explain these geographic differences in antibody responses between two groups of African origin. (AU)