Performance of Leptospira Immunoglobulin M ELISA and Rapid Immunoglobulin G Immunochromatographic Assays for the Diagnosis of Leptospirosis
Saowaluk Silpasakorn BSc*, Duangdao Waywa MSc*, Siriwan Hoontrakul MD**, Chuanpit Suttinont MD***, Kitti Losuwanaluk MD****, Yupin Suputtamongkol MD*
Affiliation : * Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand ** Chumphon Hospital, Chumphon, Thailand *** Maharat Nakhon Ratchasima Hospital, Nakhon Ratchasima, Thailand **** Banmai Chaiyapod Hospital, Burirum, Thailand
Using archived samples, we assessed the diagnostic capacity of two commercially available tests (an ELISA IgM and a rapid immunochromatographic test, ICT) for the detection of Leptospira spp. IgM and IgG antibodies to aid with the diagnosis of acute leptospirosis in febrile patients in Thailand. The sensitivities of the ELISA for the detection of IgM and the rapid immunochromatographic test for the detection of IgG were 60.7% (95% CI, 50.3 to 70.2%), and 83.2% (95% CI 73.9 to 89.6%) respectively. False positive ICT result occurred in one patient with influenza B infection. The positive rates of both assays were high after the first week of onset of fever up to third weeks of illness.
Keywords : Immunochromatographic assay, ELISA, Leptospirosis
