Abstract
Background
Hepatozoon canis is a protozoan that is transmitted by the ixodid ticks. Ingesting the tick or a section of the tick organ which is infected by the mature oocysts containing infectious sporozoite is the main source of infection in dogs. Canine hepatozoonosis infects dogs in Iran, but the vector for Hepatozoon protozoa from Iran has never been demonstrated. The present study aims to detect H. canis in dogs and vector ticks in Iran.
Methods
During the period of 2018–2019, Blood samples and ixodid ticks were collected and examined using microscopical, molecular, and serological methods. A total of 246 blood samples were collected from the cephalic vein of pet, stray, and shelter dogs (103 stray, 99 shelter, and 44 pets) of both genders and varying ages in Northwest of Iran.
Results
Microscopically, infected neutrophils with Hepatozoon spp. were detected in 5 of 246 (2.03%) thin stained blood smears with low parasitemia. Indirect immunofluorescent antibody test (IFAT) was used to test the serum samples and antibodies against H. canis were detected in 31 (12.6%) of the serum samples. Molecularly, 23 out of 246 (9.34%) blood samples were found to be infected with H. canis. A comparison of the results of 3 diagnostic methods demonstrated a good agreement between IFAT and PCR and a poor agreement between microscopical examination with IFAT and PCR. There was no significant difference in different age groups and sex of sampled dogs. However, stray dogs had significant infection rate of than pets and shelter ones. In body inspection, 141 adult ticks (31 partially engorged females, 26 fully engorged female and 84 fed males) were collected from examined dogs and all ticks were belonging to species of Rhipicephalus sanguineus (sensu lato). Positive reaction to H. canis was observed in the genomic DNA of the 7 ticks (4.96%). A BLAST analysis of obtaining sequences isolated from both dogs and ticks indicated a 99–100% similarity with H. canis 18S rRNA gene sequences in GenBank. This is the first study in Iran to detect H. canis in R. sanguineus tick.
First molecular evidence of Hepatozoon canis infection in Rhipicephalus sanguineus (sensu lato) ticks in Iran
