Rapid Diagnostic Tests Evaluated for Human Leptospirosis

The diagnosis of leptospirosis is often performed by the microscopic agglutination test (MAT) or by culture, but is confined to specialized laboratories.

Rapid Diagnostic Tests (RDTs) can be used for easy point-of-care diagnosis and three commercial kits have been evaluated for their diagnostic performance and compared with other standard assays.

Scientists at the Royal Tropical Institute (KIT; Amsterdam, The Netherlands) tested samples sent to their laboratory for leptospirosis diagnosis from July 2001 to August 2012. Blood, plasma, serum, and urine samples were cultured. The MAT was performed with a panel of live leptospires, and consisted of 16 strains of pathogenic serovars. An in-house enzyme-linked immunosorbent assay (ELISA) was developed for the detection of Leptospira-specific immunoglobulin M antibodies (IgM ELISA) and was performed with antigen prepared from the local strain Wijnberg (serovar Copenhageni, serogroup Icterohaemorrhagiae).

Three rapid diagnostic serological tests were used: Lepto Tek Dri Dot and Lepto Tek Lateral Flow (Organon Teknika B.V.; Boxtel, the Netherlands); and Leptocheck-WB, (Zephyr Biomedicals; Verna, Goa, India). Lepto Tek Lateral Flow and Leptocheck-WB are lateral flow immunochromatographic tests and LeptoTek Dri Dot is a latex agglutination assay and detects Leptospira-specific antibodies (IgM and IgG) in human sera.

The overall sensitivity for the LeptoTek Dri Dot was 75%, for the Lepto Tek Lateral, it was 78% Flow and 78% for the Leptocheck-WB. Specificity ranged from 95% to 98% in the three RDTs. Based on the first submitted sample the sensitivity was low, 51% for LeptoTek Dri Dot, 69% for Lepto Tek Lateral Flow, and 55% for Leptocheck-WB, but substantially increased when the results of paired samples were combined, although accompanied by a lower specificity, 82% for Lepto Tek Dri Dot, 86% for Lepto Tek Lateral Flow, and 80% for Leptocheck-WB.


The authors concluded that The LeptoTeK Lateral Flow presents in all scenarios with the best sensitivity and equally good specificity of all three RDT tests. All three tests, LeptoTek Dri Dot, LeptoTek Lateral Flow, and Leptocheck-WB present useful antibody tests contributing to the diagnosis of leptospirosis. However, since the overall sensitivity of the tested RDTs did not exceed 80%, one should be cautious to rely only on an RDT result, and confirmation by reference tests is strongly recommended. The study was published on July 11, 2013, in the journal Public Library of Science Neglected Tropical Diseases.

Related Links:

Dutch Royal Tropical Institute

Organon Teknika B.V

Zephyr Biomedicals