e22528 Background: The HTLV-1 and 2 virus are oncogenic retrovirus with a global distribution. Viral infection is primarily associated with two conditions: HTLV-1-associated myelopathy and adult T-cell lymphoma. Although Colombia is an endemic country for the virus, data on its incidence, prevalence, and the population characterization of infected individuals are limited. Methods: This is a descriptive observational study of a retrospective cohort from a blood donor population of Fundación Hematológica de Colombia from 2012 to 2022, to determine the seroprevalence of HTLV-1 and 2 in this population. Demographic and clinical variables such as age and gender were described to characterize the seropositive population and identify specific populations, such as women of childbearing age who are seropositive for the virus. Results: During the study 1,553,478 patients were recruited, of which 3,484 were seropositive, representing a global prevalence of 0.22% over 10 years. The annual incidences were as follows: from 2012 to 2013, 0.22%; from 2014 to 2015, 0.26%; 2016 to 2017, 0.23%; 2018 to 2019, 0.25%; 2020 to 2021, 0.15%; and in 2022, 0.12%. Among the seropositive individuals, 58% were women, and 42% were men. In the donor population studied, the order of prevalences by city was as follows: Bogotá with 48%, Ibagué 13%, Barranquilla 7%, Pasto 5%, Villavicencio 4%, Pereira 3%, Soacha 3%, Tunja 2%. The average age for seropositive women and men was 22 years. 54% of seropositive women were within the reproductive age. Conclusions: Our cohort has a higher seroprevalence compared to North America. In Colombia, the two cities with the highest prevalence are the capital of the country and the city of Ibagué in our study. From a public health perspective, it is noteworthy that approximately 1100 seropositive women for HTLV-1 and 2 are in reproductive age and could potentially transmit the oncogenic virus through vertical transmission or breastfeeding. With our results it would be in the interest of public health agencies to report positive results to women of child bearing age and positive donors to begin health counseling as soon as possible.