Risk factors for human herpesvirus 8 infection among adults in the United States and evidence for sexual transmission

Background. Human herpesvirus 8 ( HHV- 8) causes Kaposi sarcoma. In the United States, transmission routes for HHV- 8 are uncertain. Methods. The National Health and Nutrition Examination Survey III sampled individuals from the US general population ( 1988 - 1994). We used enzyme immunoassays ( EIAs) to measure HHV- 8 antibodies ( K8.1 and open reading frame [ ORF] 73 antigens) in 13,894 surveyed adults. HHV- 8 seroprevalence was examined according to sexual history and viral coinfection markers. Results. Overall, seroprevalence was low when a highly specific cutoff was used ( K8.1, 1.6%; ORF73, 1.5%) but was higher when a less- specific cutoff was used ( K8.1, 7.1%; ORF73, 7.4%). When the more- specific approach was used, K8.1 seroprevalence was similar in men and women. Men who have sex with men ( MSM) had a higher K8.1 seroprevalence ( 8.2%). Among other men, K8.1 seroprevalence was marginally associated with duration of heterosexual activity (P=.1) and was positively associated with the lifetime number of sex partners (P=.04) and with coinfections with hepatitis B virus ( 6.1% vs. 1.2% without coinfection;) and herpes simplex P <.001 virus 2 ( 2.7% vs. 1.0%; P=.003). Among women, K8.1 seroprevalence was not significantly related to duration Pp. 003 of sexual activity, the lifetime number of sex partners, or viral coinfections. The ORF73 EIA revealed similar but less clear- cut patterns. Conclusions. Among men, HHV- 8 transmission may occur through sexual activity, particularly sex with other men. No evidence was observed for heterosexual transmission to women.