Investigation of Dog Filariasis in Ilam Province, Iran

Blood filaria is an important arthropod-borne parasite concerning public health and causing disease in the host. Until now, no study has been conducted on the infection of dogs with blood filariasis in Ilam Province, Iran. This province has three different climates and is home to Culex species, which are the most prevalent vectors of the parasites reported in this province.

The present study investigated the infection of dogs with Dirofilaria immitis and Acanthocheilonema reconditum (Dipetalonema reconditum) in Ilam Province, Iran.

In this study, blood samples were collected from 139 dogs from Ilam Province. Blood samples were examined using the modified Knott method, and the polymerase chain reaction (PCR) was performed using two pairs of specific primers of the internal transcribed spacer 1 (ITS1) gene.

In a blood specimen from Sirvan City, microfilaria of Dirofilaria immitis (34 microfilariae in 1 mL of blood) was observed by the modified Knott test. The mean length and width of the microfilaria were 240 ± 8.72 and 5.4 ± 0.33 µ, with the straight end of the tail. A blood sample from Dehloran City and two samples of Sirvan were positive, and PCR results revealed a specific band at 155 bp in length. Two samples of Ilam City and one sample of Sarablah City were positive for Acanthocheilonema reconditum, and an amplicon with a length of 155 bp was observed.

The frequencies of infection with Dirofilaria immitis and Acanthocheilonema reconditum in Ilam Province were 2.6% and 3%, respectively. In the present study, infected dogs were reported from the cities of Sirvan, Sarablah, and Ilam, whose regions experience moderate winters without serious cold temperatures.