Risk Factors of Leptospirosis in Khuzestan, South West of Iran, 2012

Leptospirosis as a common zoonotic disease is the widest spread infection worldwide. Human is infected via direct contact with infected animals or through exposure or drinking contaminated water infected by animal urine. The aim of this study was to identify risk factors for leptospira infection in Khuzestan which is expected to be an endemic area for this infection. As part of an investigation on rural area in Khuzestan, this comparative study was conducted in the region. Sixty five cases, which were positive for IgM anti-leptospira antibodies, and 215 controls that were negative for IgM antibodies included in the study. A questionnaire including variables related to leptospira exposure was administered. SPSS-16 using Chi square and Fisher exact test were used to compare data. Differences with P-values less than 0.05 were considered as significant. The 95% confidence interval (CI) for the odds ratios (OR) were calculated. Occupation in rice farm was the most important risk factors (OR: 5.32, 95% CI = 2.71-10.43, P < 0.0001). Other risk factors were as: exposure to rat/rodent in house (OR: 3.53, 95% CI = 1.98-6.29, P < 0.0001), swimming in river or brooks (OR: 4.02, 95% CI = 2.21-7.47, P < 0.0001) and keeping cattle in house (OR: 11.53, 95% CI = 3.50-37.97, P < 0.0001). The main risk factors for this infection in Khuzestan are rice farming and keeping animals (such as cattle) as well as contact to rodent in houses. Another frequent risk factor was swimming in river or brooks.