Targeted screening for HTLV-1 infection in endemic and non-endemic regions: a global public health priority

Human T-cell lymphotropic virus type 1 (HTLV-1) is an oncogenic retrovirus responsible for adult T-cell leukemia/lymphoma and chronic inflammatory diseases. Although at least several million individuals are infected worldwide, surveillance remains limited and the infection is frequently overlooked. Global migration has altered the epidemiology of HTLV-1, increasing the number of carriers in previously low-prevalence regions and creating hidden high-risk clusters. As universal population screening is not cost-effective, targeted testing of groups with elevated risk has become a critical public health priority.

This review summarizes the changing global distribution of HTLV-1 and examines evidence supporting targeted screening strategies. A literature review was conducted focusing on epidemiological data, transmission dynamics, and policy initiatives in both endemic and non-endemic settings. Populations evaluated include migrants from endemic regions, family members of carriers, individuals with sexually transmitted infections, pregnant women, blood and organ donors, and patients with clinical conditions strongly associated with HTLV-1.

Expanding targeted screening offers a practical approach to reduce transmission and enable earlier clinical intervention. Integration of HTLV-1 testing into antenatal care, sexual health services, and specialty clinics is feasible. Broader recognition of HTLV-1 will be essential to reducing the global burden of this neglected infection.