Sero-prevalence of Leptospira spp. in Household and Stray Dogs by Microscopic Agglutination Test

Abstract

Background: Leptospirosis is a zoonotic disease of worldwide significance in human beings and many animals. This zoonotic disease causes infection in dogs and other pet animals and these animals can influence human’s health. Given the unknown prevalence of leptospirosis in dogs in our area, this study was performed to investigate the sero-epidemiology of leptospirosis and evaluate the seroprevalence of Leptospira serovars in both household and stray dogs by microscopic agglutination test (MAT). Methods: Serum samples of 90 dogs in two household and stray groups (45 dogs for each group) were collected. Specimens were examined by MAT (in accordance with the procedure recommended by WHO) against antigens of serovars Canicola, Grippotyphosa, Icterohaemorrhagiae, Pomona, Hardjo, Autumnalis, and Ballum. Results: In total, 6.7% of (n=6) dogs (1 stray and 5 household dogs) had a serum titer of 1:100 or more against Leptospira serovars. Dominant serovars were Canicola (8.9%), Grippotyphosa (2.2%), and Pomona (2.2%), respectively. The antibody titer against more than one serovar was observed only in one dog. The sero-prevalence was 11.1% in household dogs and 2.2% in stray dogs. Since 4 pet dogs had been vaccinated recently, it seems that the actual percentage of infection in household dogs must be just 2.2% and actual infection in dogs including stray dogs is approximately 4.4% in Tabriz. Conclusion: Fortunately, the rate of infection in Tabriz is low and this can be due to special geographical and climatic conditions, regular and annual vaccination of household dogs against this disease, and lack of suitable conditions for the growth and survival of such micro-organisms in the environment