The chemiluminescent detection of leptospiral antigen

The aim of this study was to investigate the feasibility of using enhanced chemiluminescence for the rapid detection of leptospiral antigen (L. interrogans serovar hardjo) in biological fluids, and to assess the suitability of such an assay for the early diagnosis of human leptospiral infections. The limit of detection for homologous antigen in phosphate buffered saline was 9 x 10(4) leptospires/ml. In human blood the sensitivity remained unchanged throughout the sampling time, (1.8 x 10(5) leptospires/ml), but decreased with time in human urine. The assay did not cross-react with other members of the Leptospira interrogans species, was unaffected by the presence of biological fluids but the sensitivity was reduced by contaminating bacteria. The assay was both rapid and sensitive, when compared with current cultural techniques, and offers a potentially valuable aid to the early diagnosis of leptospirosis.