Mucosal Shedding of Human Herpesvirus 8 in Men

TLDR

Human herpesvirus 8 is believed to be sexually transmitted among men who have sex with men, yet the precise mode of transmission remains unclear. The study aimed to evaluate patterns of mucosal shedding of HHV‑8 in HHV‑8‑seropositive men who have sex with men without clinical Kaposi's sarcoma. Researchers used quantitative PCR, in situ PCR, and in situ RNA hybridization on mucosal secretion samples to identify potential sources of infectious HHV‑8. HHV‑8 was detected in 60 % of seropositive men, predominantly in the oral cavity (30 % of oropharyngeal samples versus 1 % of anal/genital samples), with high viral loads and persistent saliva shedding in 39 % of men, and oral epithelial cells harboring viral DNA and RNA, while risk factors such as partner history of Kaposi’s sarcoma, deep kissing with an HIV‑positive partner, and use of inhaled nitrites were identified, suggesting that current safer sex practices may not prevent HHV‑8 transmission.

Abstract

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.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 polymerase-chain-reaction (PCR) assays, in situ PCR assays, and in situ RNA hybridization were used to identify potential sources of infectious HHV-8.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 days on which samples were obtained. The median log titer of HHV-8 from the oral cavity was approximately 2.5 times as high as the titer at all other sites. In situ hybridization studies indicated that HHV-8 DNA and messenger RNA 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 history 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.Oral exposure to infectious saliva is a potential risk factor for the acquisition of HHV-8 among men who have sex with men. Hence, currently recommended safer sex practices may not protect against HHV-8 infection.