doi:10.1093/ofid/ofz036engMendoza, Carmen dePirón, MaríaGonzález, RocíoJiménez, AnaCaballero, EstrellaRoc, LourdesBenito, RafaelRamos, José ManuelSoriano, VicenteClinical Presentation of Individuals With Human T-Cell Leukemia Virus Type-1 Infection in SpainART-2019-111336Background: although only 8%-10% of persons infected with human T-cell leukemia virus type 1 (HTLV-1) may develop virus-associated diseases lifelong, misdiagnosis of asymptomatic infected carriers frequently leads to late diagnoses. Methods: a nationwide HTLV-1 register was created in Spain in 1989. A total of 351 infected persons had been reported by the end of 2017. We examined all new HTLV-1 diagnoses during the last decade and compared their clinical presentation. Results: a total of 247 individuals with HTLV-1 infection had been reported in Spain since year 2008. The incidence has remained stable with 20-25 new diagnoses yearly. Women represented 62%. Only 12% were native Spaniards, most of whom were foreigners from Latin America (72.5%). Up to 57 (23%) individuals presented clinically with HTLV-1-associated conditions, including subacute myelopathy (n = 24; 42.1%), T-cell lymphoma (n = 19; 33.3%), or Strongyloides stercoralis infestation (n = 8; 14%). Human T-cell leukemia virus type 1 diagnosis had been made either at blood banks (n = 109; 44%) or at clinics (n = 138; 56%). It is interesting to note that Spaniards and especially Africans were overrepresented among patients presenting with HTLV-1-associated illnesses, suggesting that misdiagnosis and late presentation are more frequent in these populations compared to Latin Americans. Conclusions: given that 23% of new HTLV-1 diagnoses in Spain are symptomatic, underdiagnosis must be common. Although screening in blood banks mostly identifies asymptomatic Latin American carriers, a disproportionately high number of Spaniards and Africans are unveiled too late, that is, they already suffer from classic HTLV-1 illnesses.2019http://zaguan.unizar.es/record/7905710.1093/ofid/ofz036http://zaguan.unizar.es/record/79057oai:zaguan.unizar.es:79057Open Forum Infectious Diseases 6, 2 (2019), ofz036 [4 pp]by-nc-ndhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/info:eu-repo/semantics/openAccess