Authors : Mohammad Tooloei , Golamreza Abdollapour , Hamid Karimi and Ali Hasanpor
Abstract: Leptospirosis is an infectious zoonosis and its prevalence in sheep is unknown in Tabriz, northwestern Iran. Rodents and wildlife are a major source of infection that discharges the bacteria from their urine. The aims of the survey were evaluation of the seroprevalence of Leptospiral infection in sheep and the relationship between seroprevalence and animal and environmental factors in Tabriz. In this study, 359 serum samples randomly collected from sheep slaughtered in Tabriz industrial slaughterhouse since December 2004 to November 2005. Sera were stored at -20�C until use. They were initially screened at serum dilution of 1:100 against 6 live antigens of Leptospira interrogans serovars pomona, canicola, hardjo, ballum, icterohaemorrhagiae, grippotyphosa using the microscopic agglutination test (MAT). The samples were considered positive if 50% of agglutination of leptospire in a dilution tests serum of l: 100 were observed. Sera with positive results were titrated against reacting antigens in serial 2-fold dilutions from l: 100 to 1:800. 66 serums (18/4%) at dilution 1:100 were seropositive against 1 or 2 of serovars. Grippotyphosa and canicola were detected as the most prevalent serovars with 39.7 and 30.2%, respectively. Prevalence rates of other serovars were 16.4% for pomona, 8.2% for hardjo and 5.5% for icterohaemorrhagiae. All of samples were seronegative for ballum. Statistical analysis of the results showed that the rates of the infection in the autumn (37%) and spring (21%) were significantly higher than the other seasons (0.001<p<0.005). The rate of the infection has been statistically increased with the aging (0.001<p<0.005) and the animals with 3 and 4 pair�s permanent teeth (4-5 years old) had the highest infection rates. The infection rate in the female animals group was higher than the males ones (0.01<p<0.05). Thus, the serological infection rate in sheep in tabriz is relatively high and consequently the preventive methods must be applied to prevention of the spread of disease and its transmission to the human and other farm animals.
Mohammad Tooloei , Golamreza Abdollapour , Hamid Karimi and Ali Hasanpor , 2008. Prevalence of Serum Antibodies Against Six Leptospira Serovars in Sheep in Tabriz, Northwestern Iran. Journal of Animal and Veterinary Advances, 7: 450-455.