Tissue DonorsDeltaretrovirus InfectionsDeltaretrovirus AntibodiesNucleic Acid Amplification TechniquesBlood DonorsLiving DonorsRegistriesTissue and Organ ProcurementOrgan TransplantationSwedenDenmarkMultiple Organ FailureOrgan SizeFinlandTime FactorsOrgan SpecificityOrgan of CortiTreatment OutcomeTissue and Organ HarvestingGraft SurvivalRisk FactorsLiver TransplantationBrain DeathKidney TransplantationRandomized Controlled Trials as TopicIncidence