HTLV-1 infection: an emerging risk. Pathogenesis, epidemiology, diagnosis and associated diseases

Abstract

HTLV-1 was the first retrovirus identified as an etiologic agent of human disease [1, 2]. This virus produces several malignancies including Adult T Cell Leukemia-Lymphoma (ATLL) and Tropical Spastic Paraparesis/ HTLV Associated Myelopathy (TSP/HAM) [3]. HTLV-1 spreads through parenteral, sexual, and vertical (mother-to-child) routes [4]. It shares similar routes of transmission with other viruses including HIV and HCV that are often associated in the same patients. There are four known types of HTLV: HTLV-1, HTLV-2, HTLV-3, and HTLV-4. HTLV-1 is the most pathogenic for humans while HTLV-2 usually produces mild neurological disease. Both are prevalent worldwide. HTLV-3 and HTLV-4 have been identified only in Central Africa and usually affect non-human hominids [4]. The striking geographical distribution of the virus through Japan, West Africa and Latin America-Caribbean regions is still an unresolved puzzle. This, together with the pathogenesis, epidemiology, diagnosis, associated diseases, preventive strategies and treatments will be critically analyzed in this review, highlighting the emerging risk for Europe, exemplified with the case of Spain, and the prevention strategies to avoid it.