INTRODUCTION: Variations in human T cell lymphotropic virus type 1 (HTLV-1) proviral load (PVL) in infected individuals over time are not well understood. Objective: To evaluate the evolution of proviral load in asymptomatic individuals and HAM/TSP patients in order to help determine periodicity for measuring proviral load. METHODS: A group of 104 HTLV-1 infected patients, followed at the HTLV reference center ...