DIAGNOSIS OF LEPTOSPIROSIS BY POLYMERASE CHAIN REACTION

Abstract

 Leptospirosis is an important emerging zoonotic infection in developing regions of the world. Laboratory testing for leptospiral infections is important both for diagnosis and management of the patients. The conventional laboratory methods for diagnosis have many shortcomings. The availability of molecular techniques like Polymerase Chain Reaction (PCR) as diagnostic tool has improved speed and accuracy of detection. In this study serum samples from 100 patients were tested by the microscopic agglutination test MAT, IgM ELISA and PCR. The clinical symptoms mainly observed among the patients were fever (98%), jaundice and headache (78%), myalgia (77%). Among the 33 cases of leptospirosis diagnosed by MAT, 29 (87.9%) serum samples were positive by IgM ELISA and 4 (13%) were PCR positive. By considering MAT as the standard test, the sensitivity and specificity of IgM ELISA was 43% and 76%, respectively. A relevant finding in our study was the number of positive cases verified by PCR 4/28(14.3%) and IgM ELISA 11/28(39.3%) among the 28 unconfirmed cases by MAT, demonstrating the value of PCR in the diagnosis of human leptospirosis.