Relation between human T-lymphotropic virus type I and neurologic diseases in Panama: 1985-1990

Human T-cell lymphotropic virus type I (HTLV-I) is endemic in the Caribbean basin and in Japan. HTLV-II, a closely related virus, is endemic in several groups of native Americans, including Panamanian Guaymi. In Panama, a nationwide HTLV-I/II seroprevalence of 1-2% has been reported. We evaluated the frequency of HTLV-I/II infection in patients with neurologic diseases admitted to state tertiary hospitals in Panama City between 1985 and 1990. Nineteen of 322 patients with eligible diagnoses had antibodies to HTLV-I/II, 17 with HTLV-I and 2 with HTLV-II. HTLV-I was associated with spastic paraparesis (13 of 23, 56.5% versus 4 of 299, 1.3%, p < 0.001) and with cerebellar syndrome (2 of 13, 15.4%) and multiple sclerosis (2 of 54, 3.7%) (p < 0.05 for both diseases compared with subject with none of these diagnoses). The two HTLV-I infected patients with cerebellar syndrome later developed spastic paraparesis. HTLV-II infection was noted in one patient with cerebellar syndrome and one with amyotrophic lateral sclerosis. All patients with other diagnoses were seronegative. Among patients with spastic paraparesis, HTLV-I-infected patients were clinically indistinguishable from seronegative subjects. There is apparently an overlapping clinical spectrum of neurologic diseases associated with HTLV-I and HTLV-II infection.