Seroprevalence of human herpesvirus 6 infection in Brazilian and Japanese populations in the north-east of Brazil.

The seroprevalence of human herpesvirus 6 (HHV-6) infection was examined for 434 Brazilians and 250 Japanese immigrants living in Recife and its vicinity, in the North-East of Brazil. A total of 684 sera from the healthy individuals were screened for IgG antibodies to HHV-6 by anticomplement immunofluorescence (ACIF) test. The seropositivity rate to HHV-6 showed little difference between the two groups: namely, it was 76.5% for Brazilians and 77.2% for Japanese immigrants. The seropositivity rate was constantly higher in females than in males. The high prevalence of anti-HHV-6 antibodies among children indicates that HHV-6 infection occurs very early in life.