Background: Epidemiologic studies suggest that human herpesvirus 8 (HHV-8)
is sexually transmitted among men who have sex with men; however, the mode
of transmission is unclear.
Methods: To evaluate the patterns of shedding of HHV-8, we obtained mucosal
-secretion samples from a cohort of HHV-8-seropositive men who had sex with
men and had no clinical evidence of Kaposi's sarcoma. Quantitative polymer
ase-chain-reaction (PCR) assays, in situ PCR assays, and in situ RNA hybrid
ization were used to identify potential sources of infectious HHV-8.
Results: We detected HHV-8 in at least one mucosal sample from 30 of 50 men
who were seropositive for HHV-8 (60 percent). Overall, HHV-8 was detected
in 30 percent of oropharyngeal samples, as compared with 1 percent of anal
and genital samples (P<0.001). In 39 percent of the HHV-8-seropositive men,
HHV-8 was detected in saliva on more than 35 percent of the consecutive da
ys on which samples were obtained. The median log titer of HHV-8 from the o
ral cavity was approximately 2.5 times as high as the titer at all other si
tes. In situ hybridization studies indicated that HHV-8 DNA and messenger R
NA were present in oral epithelial cells. Among 92 men who had sex with men
and who were seronegative for the human immunodeficiency virus (HIV), a hi
story of sex with a partner who had Kaposi's sarcoma, deep kissing with an
HIV-positive partner, and the use of amyl nitrite capsules ("poppers'') or
inhaled nitrites were independent risk factors for infection with HHV-8.
Conclusions: Oral exposure to infectious saliva is a potential risk factor
for the acquisition of HHV-8 among men who have sex with men. Hence, curren
tly recommended safer sex practices may not protect against HHV-8 infection
. (N Engl J Med 2000;343:1369-77.) (C) 2000, Massachusetts Medical Society.