Human T-lymphotropic viruses types 1 and 2 in the 21st century (A systematic review)

Human T-lymphotropic viruses types 1 and 2 (HTLV-1/2) (family Retroviridae, genus Deltaretrovirus), are due to their genomic organization capable of long persistence and latency in the human body. HTLV-1 is an oncogenic virus associated with severe diseases such as adult T-cell leukemia/lymphoma and HTLV-1-associated myelopathy/tropical spastic paraparesis. HTLV-2 is not associated with the development of malignant neoplasms, but can also lead to the development of a number of severe neurological and infectious diseases. Despite the significant burden of disease associated with HTLV-1 in endemic areas, this infection remains globally neglected. Data on the prevalence of HTLV-1/2 infection in non-endemic regions are almost unavailable. Screening of blood donors for HTLV-1/2 infection markers is performed in only 50 countries worldwide. The absence of etiological therapy and specific vaccines highlights the critical importance of screening programs, preventive measures, early detection among populations at risk, and public awareness initiatives. Given the growing trends in international tourist and migration flows, enhanced epidemiological surveillance and targeted screening of high-risk groups are also essential in areas non-endemic for HTLV-1/2. The aim of this systematic review is to summarize current knowledge on the structure, genomic organization of HTLV-1 and HTLV-2, epidemiology, pathogenesis, clinical manifestations, diagnosis, treatment and prevention of HTLV-1/2-associated diseases.

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