Detection of Theileria equi and Babesia caballi using microscopic and molecular methods in horses in suburb of Urmia, Iran

Equine piroplasmosis is a severe disease of horses caused by the intra-erythrocyte protozoan, Theileria equi and Babesia caballi. The aim of this study was to identify equine piroplasmosis based on molecular and morphometrical features in horses in suburb of Urmia, West Azerbaijan province, Iran. From April to September 2011, a total number of 240 blood samples were collected randomly from horses of 25 villages. The specimens were transferred to the laboratory and the blood smears stained with Geimsa, and the morphological and biometrical data of parasite in any infected erythrocyte were considered. Extracted DNA from each blood sample was used in multiplex PCR in order to confirm the presence of B. caballi and T. equi. Microscopic observation on 240 blood smears determined that 15 (6.25%) and 5 (2.80%) samples were infected by T. equi and B. caballi, respectively. The mixed infections occurred in 2 (0.83%) samples. The results of the PCR assays showed 26 (10.83%), 14 (5.83%) and 4 (1.66%) were distinguished as T. equi, B. caballi and mixed infection, respectively. Differences in infection rates were statistically nonsignificant between male and female horses and among different age groups. Our findings indicated that T. equi and B. caballi were prevalent in horse population.