HTLV-I virus as a possible cause of Pacific spastic paraparesis

Abstract

A high-prevalence focus of tropical spastic paraparesis in the South Pacific coast of Colombia is described. Because all patients lived on the coast of the Pacific lowlands, the author named the syndrome paraparesia espástica del Pacífico (PEP). The symptoms and signs are those of an upper-motor-neuron syndrome found only in adults of both sexes.

The prevalence of the syndrome (98 x 100 000) in Tumaco, a small Colombian port, exceeds the present prevalence of motor neuron disease in Guam and the Kii peninsula. The minimal diagnostic criteria are given. Of the nearly 100 cases found, 77 were included in this paper, and 20 classical patients were brought from Colombia's Pacific coast to the Hospital Universitario del Valle in Cali, where a complete neurologic and laboratory workup was performed. Positive findings included multiple parasitisms (85%), blood eosinophilia (50%), megaloblastic (40%), positive serum VDRLs (75%), and 75% positivity for FTA-abs in CSF. Virological studies for HTLV-I showed high rates of ELISA antibodies in 100% of sera and 73% of CSF. These findings suggest an infectious process as the cause of tropical spastic paraparesis. Sexual transmission could explain why the disease affects only adults.