Serodiagnosis of severe leptospirosis: evaluation of ELISA based on the recombinant OmpL1 or LipL41 antigens of Leptospira interrogans serovar autumnalis.

AbstractELISA based on the recombinant OmpL1 and LipL41 antigens of Leptospira interrogans serovar autumnalis strain N2 have been developed, for the serodiagnosis of the severe pulmonary form of leptospirosis on the endemic Andaman Islands. The recombinant OmpL1 and LipL41 were produced using Escherichia coli expression systems and then purified before each was evaluated in an IgM-ELISA. The sera tested came from 224 patients who had the severe form of leptospirosis and pulmonary pneumonitis as major symptoms, 148 patients who, although clinically suspected to have severe leptospirosis, had been found seronegative for leptospirosis, 528 patients with diseases other than lepstospirosis, and 704 apparently healthy individuals, all from the Andaman Islands. Among the patients with the severe pulmonary form of leptospirosis, the ELISA based on the recombinant OmpL1 achieved a sensitivity of 91.1%, a specificity of 86.5%, a positive predictive value of 91.1%, and a negative predictive value of 86.5%. The corre...