Leptospiral glycolipoprotein as a candidate antigen for serodiagnosis of human leptospirosis.

Aims: Development of a simple, specific, rapid and inexpensive Dot-ELISA test for early diagnosis of human leptospirosis.
Methods and Results: Serum samples from 90 patients diagnosed with leptospirosis were analysed by Dot-ELISA test incorporating Glycolipoprotein (GLP) antigen from serovars Copenhageni and Patoc. Results were compared with those obtained with microscopic agglutination test, currently, the gold standard reference serological method. Serum samples from healthy blood bank donors and patients diagnosed with diseases other than leptospirosis were used as negative controls. The specificities of both GLP-based assays were 97.1% and 100% with serum samples from patients with other diseases and with serum samples from healthy control group, respectively. With serum samples from patients with acute leptospirosis, sensitivity was 76.6% with Dot-ELISA Copenhageni and 90.0% with Dot-ELISA Patoc. With serum samples from patients in convalescence, sensitivity was 100% with both GLP-based assays.
Conclusions: This Dot-ELISA provides a candidate antigen for serodiagnosis of leptospirosis during all phases of illness and could be a good alternative method for the early diagnosis of leptospirosis.
Significance and Impact of the Study: The Dot-ELISA test is simple, specific, rapid and inexpensive. It is suitable for identifying a large number of samples and, hence, reducing the death rate of patients with leptospirosis.