This regional project was performed in collaboration with the University Health System Donor Center in San Antonio, BloodCare in Dallas, and Gulf Coast Regional Blood Center in Houston, thus providing results for three separate metropolitan areas with rather different ethnic compositions. These studies should provide valuable information to assess the necessity and feasibility of national screening of blood donors for KSHV, and gain insight into the patterns of infection as well as the diversity, the distribution, and the origins of the virus strains in blood donors.