The human lymphotropic virus type 1 (HTLV-1) ancestral virus that is distributed endemically throughout Peru and especially in Apurimac, where it is characterized by its high endemicity; is related to adult T cell lymphoma and leukemia and tropical spastic paraparesis. Its transmission is carried out by blood and organic fluids and in some cases not yet fully evidenced by vertical transmission, in addition to its possible relationship with breastfeeding. The study was designed as a descriptive, retrospective study in which the population under study were voluntary and replacement donors who went to the Blood Bank of the Subregional Hospital of Andahuaylas in the period from 2012 to 2016. It was determined that the prevalence of the virus lymphotropic human T cells-HTLV-I and II, in donors who attend a Blood Bank of the Subregional Hospital of Andahuaylas was 2.09%, which corroborates the...