TRANSMISSION OF HUMAN-HERPESVIRUS-7 THROUGH MULTIGENERATIONAL FAMILIES IN THE SAME HOUSEHOLD

Background. Human herpesvirus 7 (HHV-7) closely resembles HHV-6 and to a lesser degree cytomegalovirus, HHV-7 infection is usually acquired during early childhood, Primary infection can cause a roseola-like ill ness but in most cases it is only mildly symptomatic, The majority of adults are seropositive and in contrast to HHV-6 and cytomegalovirus i nfection, they continue to secrete the virus in their saliva for many years. The mode of intrafamilial transmission of this virus is not wel l-understood. Methods. Saliva samples for virus isolation and DNA rest riction analysis were obtained from all 47 members of 6 Japanese famil ies, including 4 families with 3 generations living in the same househ old. Results, HHV-7 was isolated from 43 of 47 saliva samples collecte d from children and adult members of the 6 families (91.5%), In one fa mily the restriction patterns of the maternal grandmother, the mother and the children were similar, and the patterns of the paternal grandm other and the father were similar, In another family the patterns of t he father and 5 of 6 children were similar, and those of the mother an d the other child were similar. Altogether similar HHV-7 restriction p rofiles with his or her mother were found in 48% of offspring, and sim ilar profiles with his or her father were found in 28% of offspring. C onclusions. The results strongly suggested horizontal transmission of HHV-7 from grandparents to parents to children through close contact w ithin a household, Either parent could transmit HHV-7 to the children.