HTLV-NEGATIVE AND HTLV TYPE I-POSITIVE TROPICAL SPASTIC PARAPARESIS IN NORTHEASTERN BRAZIL

A type-specific serological survey among 1042 random nonneurological o utpatients in two cities in the state of Ceara (northeastern Brazil) s hows a low prevalence of HTLV-I (0.34% in Fortaleza; 0.44% in Crate) a nd of HTLV-II (0.34% in Fortaleza; 0% in Crate). Among 62 chronic myel opathic patients seen in Fortaleza 27 patients were found with clinica l features of tropical spastic paraparesis (TSP); 10 of 27 were found HTLV-I seropositive (37%; 95% confidence limits, 19-58%). Proviral gen ome detection by polymerase chain reaction in 5 seropositive and 12 se ronegative patients confirmed the serological findings. This excludes HTLV-I or -II infection as a cause in the seronegative TSP patients. T he HTLV-positive and -negative patients did not differ clinically and by history, except that seropositives had a longer mean disease durati on, a female predominance, and a higher proportion of white Caucasians . In this population with low HTLV-I and HTLV-II prevalences, HTLV-neg ative TSP is at least as frequent as the HTLV-I-associated TSP.