Tropical spastic paraparesis/HTLV-I-associated myelopathy in Brazil.

Brazil, the largest Latin American country, is highly heterogeneous, both demographically and socioeconomically. The overall human T-cell lymphotropic virus type I (HTLV-I) seroprevalence among blood donors is approximately 0.45%. These rates are highly variable, from 0 to 1.8%. Since 1989, many series of tropical spastic paraparesis/HTLV-I-associated myelopathy (TSP/HAM) cases have appeared in the literature, with high variation in the prevalence of HTLV-I among TSP patients (14.7-57%). The main clinical features of Brazilian TSP/HAM are similar to those in other endemic countries, but sensory signs are more frequent. Recently, the presence of peripheral nerve and muscular involvement has been characterized. The first nationwide study on the disease has been recently completed: it enrolled 163 patients and concluded that TSP/HAM is common in Brazil, mainly in the northeast and southeast regions; it predominates among women and whites; the most important risk factors for infection are sexual promiscuity and blood transfusion; and, although a remarkably uniform disease throughout the country, some statistically significant differences were detected, such as a higher proportion of females over males in the northeast region, a higher proportion of whites the southeast and the south and mulattos in the northeast, and, finally, a high rate of venereal diseases in the southeast region and of intravenous drug use in the south. Brazil seems to be a perfect setting for future epidemiologic, clinical, basic, and therapeutic studies on TSP/HAM.

Clinical and demographic features of HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP) in Rio de Janeiro, Brazil.

In Rio de Janeiro (RJ) most cases of paraparesis of obscure origin are associated with the human T-cell lymphotropic virus type I (HTLV-I). Thirty-four consecutive patients with HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) from RJ were evaluated. Most patients came from low socio-economic levels. There was no difference in terms of gender. The main affected racial group was white. A history of sexually transmitted diseases was a major risk factor for HAM/TSP and a positive serology for syphilis was found in 26.5% of the patients. The major clinical findings were of a spastic paraparesis with generalized brisk tendon jerks and bilateral Babinki's sign. Sensation was abnormal in 25 patients (73.5%) and five (14.7%) had a sensory level. Three patients (8.8%) had optic atrophy. The cerebrospinal fluid showed a lymphocytic pleocytosis with a mean total protein content of 0.4 g/litre, and an increased intrathecal IgG synthesis in 59.4% of patients. HAM/TSP and multiple sclerosis (MS) occur indigenously in RJ and some HAM/TSP cases can be sometimes confused with MS. Therefore we propose that, in places where MS coexist with HAM/TSP, HTLV-I antibodies should be sought routinely in those MS suspected cases with prominent spastic paraparesis.