Serological tests for Lyme disease in patients with tropical spastic paraparesis and healthy Jamaicans

The significance of reactive serological tests for Lyme disease in patients with tropical spastic paraparesis (TSP) was assessed by examining serum samples from 128 of these patients and 200 healthy Jamaicans by Lyme indirect immunofluorescent antibody (IFA), enzyme immuno-assay (EIA) and Western blot analyses. Sera were also examined in serological tests for syphilis (STS), an unabsorbed fluorescent treponemal antibody test and leptospira microagglutination test. The prevalence of positive Lyme IFA and EIA results did not differ significantly between sera from TSP patients (12.5%) and healthy controls (10.0%). Western blot analyses showed that the positive Lyme IFA and EIA results observed in this study were due to false positive reactions. Seventy-five per cent of Lyme IFA/EIS positive sera from TSP patients had treponemal antibodies. Eighty per cent of those from healthy controls were negative in standard STS but 85% were positive when tested in an unabsorbed fluorescent treponemal antibody (FTA). These data indicate that reactive serological tests for Lyme disease in Jamaican TSP patients and healthy Jamaicans are false positive reactions due to cross-reactivity with other spirochaetes, notably Treponema pallidum and non pathogenic treponemes.