Evaluation of two enzyme-linked immunosorbent assay methods for detection of immunoglobulin M antibodies in acute leptospirosis.

Abstract

Abstract. Leptospirosis is a common zoonosis of worldwide distribution. Diagnosis of leptospirosis is usually accomplished by serology, but the microscopic agglutination test (MAT) generally requires paired sera for detection of seroconversion and is considered too complex for routine use. A number of rapid assays have been developed in recent years. In the present study, 2 immunoglobulin (Ig) M enzyme-linked immunosorbent assay (ELISA) methods were evaluated for the early diagnosis of acute leptospirosis in Barbados. A total of 103 patients admitted to the Queen Elizabeth Hospital for diagnosis of suspected leptospirosis were investigated. A case of leptospirosis was confirmed by a 4-fold rise in titer between 2 sera tested by MAT, an initial titer of Ն 800 in the MAT, or by isolation of leptospires from blood or urine. A total of 48 cases of leptospirosis were confirmed. In 33 cases, both commercial assays were positive in the first sample, taken at admission, a mean of 6.7 days after onset of symptoms, whereas seroconversion was detected in a further 9 cases. Both assays were negative in 5 cases, and the remaining case gave discordant results in the 2 assays. False-positive IgM results were detected in 4 patients without leptospirosis. The sensitivity of the 2 assays was 89.6 and 97.5%, respectively, and specificities were 92.7 and 96.4%, respectively. The positive predictive values were 87.8 and 95.5%, and the negative predictive values were 90.7 and 89.5%, respectively. Either of these assays can be used for early diagnosis of leptospirosis, particularly in laboratories that cannot perform more specialized leptospiral serology.

Redefining Gold Standard Testing for Diagnosing Leptospirosis: Further Evidence from a Well-Characterized, Flood-Related Outbreak in Sri Lanka

“…Previous studies have consistently shown ELISA to be more sensitive than MAT in the acute phase. 36 Sensitivity of MAT, even with properly obtained paired samples, is not 100% as specified in several other studies. 10 We observed similar results in the 2008 Sri Lanka leptospirosis outbreak, with two additional patients detected only using qPCR.…”

Leptospirosis as a Cause of Fever in Urban Bangladesh

“…4,10 Serum polymerase chain reaction or blood culture can provide a definitive diagnosis, 12 but are not widely available. Tests for the presence of genus-specific IgM, 13 which develops within the first week of infection and persists for months, 14 may be used for screening, and a microscopic agglutination test (MAT) can provide greater specificity along with some indication of the infecting serovar. 15 Leptospirosis has been described in several regions of India, [16][17][18][19] but data on the epidemiology of leptospirosis in Bangladesh are limited.…”

Development of Leptospira Killed Whole Culture Vaccine Using Different Adjuvants and Evaluation of Humoral Immune Response in Hamsters

“…Briefly, the wells of polystyrene plates (Nunc) were coated with 100 µl of antigens (10 9 Leptospira boiled in carbonate buffer, 0.1 M, pH 9.6) [19]. The plate was washed three times with 0.1 M PBS containing 0.05% Tween 20 ( PBST) and then blocked with 200 µl/well of 1% BSA for 2 h at room temperature.…”