Risk factors for Kaposi's Sarcoma-associated herpesvirus infection among HIV-1-infected pregnant women in the USA

Objectives: We sought to identify risk factors for infection with the Kaposi's Sarcoma-associated herpesvirus (KSHV) among pregnant women and to examine a reported association of KSHV with injecting drug use (IDU) and hepatitis C virus (HCV) infection. Design: Cross-sectional evaluation of questionnaire data and KSHV and HCV seroprevalence in the Women and Infants Transmission Study. Methods: In sera collected from HIV-1-infected pregnant women (n = 887) and, at age 12 months, their offspring (n = 900) at six sites in the USA and Puerto Rico, KSHV and HCV antibodies were detected with sensitive and specific enzyme immunoassays. Risk of KSHV was estimated by the unadjusted and adjusted odds ratio (OR_adj) and 95% confidence interval (CI). The geographic referent sites were Chicago and Boston. Results: Forty-seven (5.3%) of the women and three (0.3%) of the infants were KSHV seropositive. In univariate and multivariate analyses, KSHV in the women was associated with enrollment in Puerto Rico, Houston or Brooklyn (OR_adj, 4.3; 95% CI, 1.8-10.4) or Manhattan (OR_adj, 9.8; 95% CI, 3.7-25.6); non-completion of high school (OR_adj, 1.8; 95% CI, 0.9-3.4); the number of sexually transmitted diseases (OR_adj, 1.4; 95% CI, 1.0-1.9 per disease); and especially with IDU and HCV infection (OR_adj, 3.5; 95% CI, 1.5-7.9). Conclusions: Transmission of KSHV by blood inoculation may be highly inefficient, but our data support the hypothesis that it does occur. Large formal studies to evaluate whether KSHV transmission occurs via transfusion are needed to inform decisions regarding screening volunteer blood donors to protect the blood supply.