Seroepidemiology of leptospirosis in Guilan province, northern Iran: Comparison between MAT and IgM-ELISA techniques

Abstract

Introduction: Leptospirosis is a widespread zoonotic disease which is endemic in Guilan province, Iran. Besides economic losses in the dairy industry, leptospirosis is also considered an important public health problem. This study aimed to evaluate two serological techniques, MAT and IgM-ELISA for detection of leptospiral antibodies. Methodology: A total of 185 samples were collected from individuals in Guilan province suspected of having leptospirosis from April 2016 to December 2016. Sera from participants were analyzed for Leptospira IgM antibodies using an available ELISA test and the MAT method. The specificity and sensitivity of the tests were calculated and compared. Results: Of the 185 serum samples examined 114 (61.6%) and 94 (50.8%) samples were determined to be positive by MAT and IgM-ELISA, respectively. The results also showed that 17.5% of the sera that reacted positive in MAT were negative by IgM-ELISA, and 20.2% of IgM-ELISA positive sera were negative by MAT. We also showed that the MAT had specificity and sensitivity of 100%, when compared to leptospirosis-positive and negative serum samples. The specificity and sensitivity of IgM-ELISA was calculated as 78.8% and 82.4% respectively when compared with MAT. Bivariate analysis showed high correlation between the season, community of residence, possible reasons of pollution and leptospirosis (P < 0.1). Conclusion: Rural areas of Guilan, especially rice farming areas, are endemic for leptospirosis. Rice farmers have a high risk of infection with leptospirosis; infection is associated with direct exposure to rodent urine, gender (male) and season (spring).