Background: Sequences of novel herpesvirus, Kaposi's sarcoma-associated herpesvirus (KSHV), have been indentified in Kaposi's sarcoma tissue, but it is not known whether the virus is transmitted by sexual contact.
Methods: Using the polymerase chain reaction (PCR), we searched for KSHV DNA sequences in ejaculates from 43 healthy men and tissue from the urogenital tract or prostate of 100 immunocompetent adults.
Results: In an unblinded analysis, we identified KSHV DNA sequences in 2 of 20 tissue specimens from the urinary tract (10 percent; 15 men and 5 women), 3 of 46 specimens from the female genital tract (6.5 percent), 4 of 18 specimens from the glans or foreskin (22 percent), 7 of 16 specimens from the prostate (44 percent), and 30 or 33 ejaculates (91 percent). By contrast, such sequences were present in 1 of 18 samples of normal skin (5.5 percent) and 1 of 14 samples of peripheral-blood mononuclear cells (PBMCs; 7.1 percent). Ejaculates and PBMC samples from each of 10 study subjects were analyzed in a blinded, coded fashion, along with PBMCs and biopsy specimens of normal skin from 4 and 8 other patients, respectively. This analysis confirmed the presence of KSHV DNA sequences in semen. Viral DNA was not found in the sperm heads but was present in the fraction of the ejaculates that contained urothelial and other types of cells. Point mutations were found in PCR products amplified from both prostate tissue and sperm samples.
Conclusions: KSHV infects a large proportion of healthy adults and is probably transmitted by sexual contact.