A viral infectious disease that results in increased proliferation of affected CD4 lymphocytes, has material basis in Human T-lymphotropic virus 1, which is transmitted by sexual contact, transmitted by contaminated needles used by intravenous-drug users, and transmitted by breast feeding. The person infected with HTLV-1 eventually develop an often rapidly fatal leukemia, while others will develop a debilitative myelopathy, uveitis, infectious dermatitis, or another inflammatory disorder.