HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP)
is a chronic, progressive disease of the nervous system that affects less than 2 percent of people with HTLV-1 infection. Signs and symptoms vary but may include progressive weakness, stiff muscles, muscle spasms, backache, a 'weak' bladder, and constipation. The HTLV-1 virus can be transmitted from mother to child via breastfeeding or childbirth, from person to person through sexual contact and through blood contact, either by transfusion or by reuse of injection equipment. HTLV infection is not passed from person to person by coughing, sneezing, kissing, cuddling or daily social contact. Screening of donated blood for HTLV-1 has been done in the United States since 1988. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.