Tropical spastic paraparesis/HTLV-I-associated myelopathy in Europe and in Africa: clinical and epidemiologic aspects.

We review here the epidemiologic and clinical aspects of tropical spastic paraparesis, human T-cell lymphotropic virus type I (HTLV-I)-associated myelopathy (TSP/HAM) as observed in Europe and in Africa. Europe is not an endemic region for HTLV-I (seroprevalence in blood donors, < 0.03%), and TSP/HAM is thus rarely observed in European countries. Most of the few patients suffering from TSP/HAM are first- or second-generation immigrants from HTLV-I endemic areas (mostly the West Indies), and the clinicoepidemiologic aspects of these patients are similar to those seen in endemic areas. However, rare cases occur in European-born subjects with or without risk factors for HTLV-I infection, which raises the possibility of limited foci areas in Europe. Although Africa is considered as a primary HTLV-I endemic area, with at least a few million infected inhabitants, epidemiologic data on the situation of TSP/HAM in Africa remain scarce. Relatively few cases of patients with TSP/HAM have been reported in Africa, including some clusters in Zaire (prevalence, 50/100,000) and in South Africa and sporadically in the main cities of some Western, Central, and Eastern African countries. The paucity of clinical and epidemiologic data on TSP/HAM may be linked to several factors, including the paucity of neurologists, the lack of laboratory and radiologic facilities, and the chronicity of the disease, along with the limited number of field epidemiologic studies performed on this topic and the wide diversity of causes (toxic, nutritional, and infectious) of chronic myelopathies as seen on the African continent.