Global epidemiology of HTLV: Under-reported and under-studied regions.

To examine the global epidemiology of human T-lymphotropic viruses (HTLVs), with a focus on under-reported and under-studied regions such as Turkiye, and to highlight public health challenges, including insufficient surveillance and lack of awareness. A comprehensive review of published literature and epidemiological data was conducted to identify trends, prevalence rates, and gaps in surveillance. Key sources included peer-reviewed journals and global health reports. HTLV-1 was identified as highly endemic in regions such as Japan, the Caribbean, South America, and sub-Saharan Africa. Limited data were available for Turkiye and adjacent regions, with estimated prevalence rates below 0.1%. Insufficient screening, stigma, and resource constraints were noted as major barriers to improved surveillance and prevention. HTLVs remain a neglected public health issue with significant implications for healthcare systems. Targeted research, expanded surveillance, and public health interventions are urgently needed, particularly in under-studied regions like Turkiye and Southeast Asia. Human T-lymphotropic viruses (HTLVs) are globally distributed retroviruses with significant health implications, particularly in endemic regions. Despite the known association of HTLV-1 with adult T-cell leukemia/lymphoma (ATLL) and HTLV-associated myelopathy/tropical spastic paraparesis (HAM/TSP), comprehensive epidemiological data are lacking for several regions. This review examines the global epidemiology of HTLV, with a particular focus on under-reported and under-studied areas, including Turkiye. Highlighting the public health challenges posed by insufficient surveillance, lack of routine screening, and limited awareness, this review emphasizes the urgent need for global efforts to address this neglected public health issue.