[Pathologies associated with HTLV-1 virus in Dakar (1992-1995)]

A clinical and laboratory study was conducted in Dakar (Senegal) to assess the involvement of HTLV-1 virus (human T lymphotrophic virus type 1) in various diseases. Patients were enrolled at three locations: the Dermatology Department of the Fann University Hospital Center (845 patients) from 1992 to 1995, the Dermatology Department of the Le Dantec University Hospital Center and the Oncology Department of the Principal Hospital (7 patients) in 1994 and 1995. The incidence of involvement of human retroviruses in neurologic complications seemed low (HTLV-1: 2%, HIV: 3%) and only 6 cases of tropical spastic paraparesis associated with specific anti-HTLV-1 antibodies were diagnosed in 3 men and 3 women with a mean age of 51 years. These cases which were identical to those previously described cases in the West Indies and Japan confirms the existence of this disease in Senegal. In addition 3 cases of isolated facial paralysis were observed in HIV positive patients. Combined HIV/HTLV-1 infection was observed in 3 cases and was not associated with special clinical findings. Adult T-cell leukemia/lymphoma (ATL) was detected in 4 patients including leukemia with proliferation of CD4 and CD25 in two cases and lymphoma in one case. In one case of ATL two proviruses were identified in circulating tumor cells. These are the first cases of ATL to be reported in Senegal. Molecular characterization of part of the envelope gene (gp 21) from patients with PST hospitalized in a neurology ward showed that the virus present in Senegal belonged to the universal HTLV-1 A type. This study indicates that two types of diseases are associated with HTLV-1 infection in Senegal. Further epidemiologic studies will be needed to evaluate the incidence of the virus and of the diseases associated with it. Prevention will depend partly on screening blood donors as has now been started at the Blood Transfusion Center of Dakar.