Serological study of Dirofilaria immitis in urban dogs of Urmia using modified knot and rapid antigen tests

Dirofilariasis is a zoonotic infection caused by Dirofilaria immitis (D. immitis) the causative agent of canine and feline cardiopulmonary dirofilariasis (heartworm disease) in temperate and tropical areas throughout the world and Iran. The parasite is transmitted by different species of culicid mosquitoes. In order to study on D. immitis in healthy urban dogs in Urmia region, and comparison of two diagnostic methods i.e. modified knot test and rapid antigen test kit, the number of 100 dogs (63 males and 37 females) were undertaken to this study in a period of April till July (2014). After physical restriction, blood samples were collected from cephalic or saphenous vein in the appropriate tubes which transferred to the laboratory in an ice pack. Modified knot test was used to recognize D. immitis. Then, all samples were tested by Antigen rapid test kit. There was a difference between the result of modified knot test and rapid test kit. The results indicated that out of 100 samples, 3 samples were infected by D. immitis. There were no significant differences in dirofilariasis infection among different gender and ages. It is concluded the antigen rapid test should be accompanied by another diagnostic method in order to avoid false negative results.