WHO Initiates Development of First Global Guidelines on HTLV-1 Testing and Prevention

The World Health Organization (WHO) has announced the development of new global recommendations to address Human T-cell Lymphotropic Virus Type 1 (HTLV-1). Identified in 1977 as the first human retrovirus, HTLV-1 affects an estimated 5–10 million people globally but remains a neglected sexually transmitted infection (STI).

HTLV-1 is endemic in specific geographic regions, including:

Western and Central Africa
Latin America
The Western Pacific Region

Serious Health Consequences of HTLV-1

Infection with HTLV-1 can lead to two severe, progressive conditions:

Adult T-cell Leukaemia/Lymphoma (ATL): An aggressive malignancy affecting the blood and blood-forming organs.
HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP): A progressive neurological condition.

Despite the serious consequences and high prevalence in endemic areas, few concerted public health measures have been implemented globally, with most high-income countries limiting their response to screening of blood donations.

New Guidelines to Drive Public Health Action

This upcoming set of recommendations will be the first global guideline to incorporate the latest evidence and best practices for addressing HTLV-1. The primary goal is to stimulate a comprehensive global public health response to contain the infectious disease.

Collaboration: The work is being led in close collaboration with the Pan American Health Organization (PAHO).
Guideline Development Group (GDG) Meeting: The GDG is scheduled to meet virtually on 8-9 December 2025.
Objectives: The meeting will aim to provide evidence-based recommendations and guidance on HTLV-1 testing and prevention, specifically addressing:
- Who to test
- How to test
- Resource use
- Broader prevention approaches

These guidelines are expected to feed into a larger process of setting priorities and principles for HTLV-1 testing and prevention worldwide.