Asymmetrical transmission of human herpesvirus 8 among spouses of patients with Kaposi sarcoma.

BACKGROUND: Among heterosexuals, the sexual transmission of human herpesvirus 8 (HHV8) has not been established. OBJECTIVES: To assess HHV8 seroprevalence in spouses of patients with classic and endemic Kaposi sarcoma (KS) and to suggest possible routes of transmission. METHODS: A case-control study was carried out in a teaching hospital among spouses of human immunodeficiency virus-negative patients with KS (cases - exposed subjects) and controls who did not have KS nor were related to patients with KS (nonexposed subjects). HHV8 seroprevalence in spouses of patients with KS was compared with HHV8 seroprevalence in controls matched for age, gender and place of birth. Other serology tests were compared between cases and controls. Among heterosexual couples, HHV8-seropositive and HHV8-seronegative spouses were compared for possible risk factors for virus transmission. RESULTS: HHV8 seroprevalence was significantly higher among spouses of patients with KS (13 of 22; 59%) than among matched controls (19 of 58; 33%; P = 0.043). Among heterosexual couples, five of five (100%) male spouses were HHV8 positive vs. six of 15 (40%) female spouses (P = 0.04). There was no significant difference between HHV8-seropositive and HHV8-seronegative spouses for all other factors screened for among heterosexual couples. CONCLUSIONS: Being a spouse of a patient with KS is a risk factor for HHV8 seropositivity. Our results suggest that female-to-male HHV8 transmission could be more efficient than male-to-female transmission among couples including a patient with KS. Transmission could involve distinctive behaviours, or currently unknown biological properties of HHV8.