Seroprevalence Study of Leptospirosis Among Rice Farmers in Khuzestan Province, South West Iran, 2012

BACKGROUND Leptospirosis as an emerging infectious disease is considered as an important public health problem worldwide. OBJECTIVES The current study aimed to identify potential risks for leptospirosis among rice farmers in Khuzestan province, Iran. PATIENTS AND METHODS A cross-sectional study was carried out in Khuzestan, South west Iran, from October to December, 2012. Randomly selected participants were placed in two groups: Rice farmers as cases, and non-farmers as controls. Blood samples obtained from the participants were tested for IgM anti-leptospira antibodies using Serion ELISA classic ESR 125M. The assays were performed and interpreted according to the manufacturer's instructions. A questionnaire including variables related to Leptospira spp. exposure was administered to each participant. SPSS software version 16 was employed; Chi square and Fisher's exact tests were used to analyze data. RESULTS Of the total 288 samples, 65 (22.5%) were positive for IgM anti-leptospira antibodies. Among the positive samples, 52 (36.1%) were from the case (rice farmer) and 14 (9.7%) from the control groups. There was a significant difference between the case and control groups regarding leptospiral infection (P < 0.0001). Mean age in male and female in the case and control groups were 44.2, 41.9 and 43.5, 41.2 years, respectively (P > 0.05). In the case group, males and those more than 35 years were at a higher risk of infection. CONCLUSIONS Rice farmers are significantly infected with leptospirosis, and infection prevalence is highly affected by gender (male) and age (above 35 years). Rice farming parts of Khuzestan, Iran may be considered as endemic for leptospirosis.