[Leptospirosis screening: performance of the Serion Elisa Classic Leptospira IgM KIT]

Evaluate the sensitivity and the specificity of anti-Leptospira IgM detection with the Serion Elisa classic kit in comparison to the Panbio Elisa kit.

Twenty-three sera of patients whom Taqman probe real time PCR is positive and 19 sera positive by the microscopic agglutination test (MAT) are studied for sensitivity. Specificity is evaluated with 49 pairs of sera negative by MAT and with sera positive in IgM to EBV, to syphilis, to Borrelia and positive to influenza virus antibodies.

14/23 (61%) of the sera positive by PCR and 27/30 (90%) of the sera positive at significant level by MAT are positive by Serion IgM Elisa. Serogroups Icterohaemorrhagiae, Grippotyphosa, Australis, Tarassovi, Canicola, Sejroe, Patoc and Cynopteri are detected. 40/49 sera (82%) negative by MAT are negative by Serion IgM Elisa. Agreement with the Panbio kit is 61% (30/49). Results are discrepant in 19/49 cases corresponding to a positive result by Panbio IgM and to a negative result by Serion IgM. Serological cross-reactions are more frequent with IgM to syphilis and to Borrelia than with IgM to EBV and to influenza virus antibodies.

A similar sensitivity is observed between the two kits but specificity is higher with Serion. Positivity in IgM is 61% in cases of leptospirosis diagnosed by PCR.