Human herpesvirus 8 transmission from mother to child and between siblingsin an endemic population

Background Transmission or human herpesvirus 8 (HHV-8), the aetiological ag ent of Kaposi's sarcoma, is known to occur during sex among homosexual men. However, other modes of HHV-8 transmission remain to be elucidated in ende mic populations. Methods We did a population-based seroepidemiological survey in a village i n French Guiana among 1337 individuals of African origin (age 2-91 years) w ho had reliable genealogical data. Plasma samples were taken and tested for HHV-8-specific IgG by immunofluorescence assay. Risk factors and familial correlations for HHV-8 seropositivity were modelled by logistic regression analysis by use of the estimating equations approach, which expresses famil ial dependences in terms of odds ratios. Familial odds ratios were also acq uired by use of the distribution of all possible pairs of a given familiar dependence. Findings The overall HHV-8 seroprevalence was 13.2% with no difference acco rding to sex. HHV-8 seropositivity was strongly age;dependent: at 1.2% unde r 5 years, HHV-8 seroprevalence rose up to a plateau around 15% between 15 and 40 years, and showed a seroprevalence of more than 27% in individuals o lder than 40 years. Strong familial aggregation in HHV-8 seroprevalence was found with high mother-child (odd ratio 2.8 [95% CI 1.6-5.0]) and sib-sib (3.8 [1.6-9.5]) correlations. By:contrast, no significant correlation betwe en spouses (0.6 [0.2-1.9]) was seen. Interpretation This pattern of familiar aggregation, together with the vari ation of HHV-8 seroprevalence with age, indicate that, in endemic populatio ns, HHV-8 transmission mainly occurs from mother to child and between sibli ngs during childhood and adolescence.