Seroprevalence of human herpesvirus 6 in Andino Punenos (Argentina)

We carried out a seroepidemiological survey to define the prevalence of hum an herpesvirus 6 (HHV6) infection in an aboriginal population (Andino Punen os) from a remote region in north-west Argentina. Antibodies against HHV6 ( total IgG and the 4 subclasses of IgG) were studied in 84 serum samples (co llected in 1995 and stored at -70 degreesC), using cord blood mononuclear c ells infected with HHVG in an immunofluorescence assay. Of the 84 samples, 70 (83%; 95% confidence interval, 75-91%) exhibited IgG antibodies against HHVG. No significant differences in the frequency of humoral immunity were found among the 4 age-groups studied (mean ages 13, 31, 47 and 70 years) na mely, 75%, 89.7%, 79.2% and 100%, respectively. HHV6-specific IgG1 was foun d in all the positive serum samples rested but none of them contained speci fic IgG2, IgG3 and IgG4. These results confirmed a high rate of infection w ith HHVG within this aboriginal group in Argentina and an IgG1 anti-HHV6 ac tivity compatible with a maintenance of immunity.