Human herpesvirus 8 (HHV-8) has been proposed as a sexually transmitted eti
ologic agent of Kaposi's sarcoma (KS). In this study, by use of a sensitive
polymerase chain reaction assay, HHV-8 DNA was detected in the skin lesion
s (92%), normal skin (23%), peripheral blood mononuclear cells (PBMC) (46%)
, plasma (7%), saliva (37%), and semen (12%) but not stool samples from KS
patients. The average number of HHV-8 copies per microgram of positive targ
et DNA was 64,000, 9000, 40, 33,000, and 300 for skin, PBMC, plasma, saliva
, and semen samples, respectively. Only 1 non-KS donor sample, of saliva, w
as positive for HHV-8. Sequencing showed 5% divergence among HHV-8 strains.
The data suggest that saliva may be more important than semen or stool in
the sexual transmission of HHV-8. The relatively high prevalence of HHV-8 i
n PBMC raises the question as to why there is no evidence for bloodborne vi
rus transmission.