The Distribution of Hard Ticks as a Vector of Crimean-Congo Hemorrhagic Fever in the Border Areas in the North West of Iran

Ixodidae (hard ticks) are obligate blood-feeders of vertebrates with major roles in transmission of pathogenic microorganisms including theileriosis, babesiosis and CCHF virus, as well as relapsing fever, to domestic animals and humans. This study was conducted to determine the distribution of ixodidae  species, vectors of Crimean-Congo hemorrhagic fever (CCHF), in the border areas in North West of Iran. This was a descriptive cross-sectional study conducted in Ahar and Kaliybar Counties, East Azarbaijan Province, Iran. Randomized cluster sampling was done in villages in the forest and mountainous regions. Ticks were isolated by forceps from the animals, kept in sampling tubes and transferred to the laboratory. Then the tick samples were identified using taxonomical keys. A total of 2022 hard ticks were isolated from 1400 head of livestock (1000, 200, 180 and 20 head of sheep, goat, cow and buffalo, respectively).  On the average, the infestation rate was 1.44 per head of cattle ─ 0.11% in goats, 0.32% in sheep, 0.90% in buffaloes, 9.25% cows. Out of the ticks isolated, 498 (24.63%) were male, 741 (36.65%) were female and 782 (38.67%) nymph, plus one larva. The ticks belonged to the lxodidae family, including four genera:               Hyalomma (88.82%, with the following three species: Hyalommaanatolicum (39.22%), Hyalommamarginatum (9.15%) and Hyalommaasiaticum (0.69%)); Rhipicephalus (8.8%); Dermasentor (1.58%); and Haemaphisalis (0.8%). The others identified were Hyalomma nymph (38.67%), Hyalomma sp. (1.04%) and Hyalomma larva (0.05%), Rhipicephalus bursa (5.19%), Rhipicephalussanguineus (3.61%), Dermasentor marinates(1.58%), Haemaphisalissulcata (0.59%), and Haemaphisalispunctata (0.15%), as well as Haemaphisalisconcinae (0.05%).  Hyalommaanatolicum was the dominant species.                                                                                                                                             The dominant tick species in the regions studied was Hyalommaanatolicum, a tick having a major role in transmission of many disease vectors including CCHF, ovin babesiosis, theileriosis, anaplasmosis, ehrlichiosis, etc. It is essential that the provincial Contagious Disease Center and Veterinary Department take appropriate action with the collaboration of other relevant departments to combat the tick.