The first aim of the study was to determine the prevalence of KSHV infection in blood donors using specific KSHV serologic assays. The investigators used recently developed KSHV specific serologic assays for detecting antibody to KSHV latent nuclear antigen, lytic antigen, and orf65 (lytic antigen minor capsid protein) to determine the prevalence of KSHV infection in a cross-sectional study of four representative blood banks in San Antonio, Dallas, and Houston, Texas. A total of 500 random donors at each site were studied to detect site-specific seroprevalence to plus or minus 2 percent with 95 percent confidence.