Monthly Infestation Characteristics of Ticks on Cattle in Thrace, a Crimean Congo Hemorrhagic Fever-endemic Area of Turkey

The first etiologically confirmed cases of Crimean-Congo hemorrhagic fever (CCHF) in humans were detected in Turkey in 2002. Since then, thousands of cases have been reported from different parts of the country. Hyalomma (Hy.) marginatum is considered the main vector tick of CCHFe in Turkey, and the primary infection route for humans is known to be the tick bite. This study was carried out between January 2013 and December 2014 in Thrace, Turkey, to determine monthly prevalence and intensity of tick infestation in cattle and, ultimately, to predict the related risk of human exposure to ticks and tick-borne diseases. During the study, 1,701 cattle in 24 villages were screened for ticks; 24,012 adult ticks, 1,887 nymphs, and 766 larvae were encountered on 1,228 of these cattle. On the 1,318 cattle that routinely grazed in the daytime, Hy. marginatum was the most predominant species, with an infestation prevalence of 73.6% and an average tick intensity of 16.1 on the infested cattle. In order of prevalence (%) in the grazing cattle, Hy. marginatum was followed by Rhipicephalus (R.) bursa (32.7%), R. turanicus (%29.5), Ixodes (I.) ricinus (15.1%), Haemaphysalis (Ha.) parva (10.4%), Ha. inermis (10%), Ha. punctata (6.5%), and Dermacentor (D.) marginatus (2.3%). The obtained data were discussed in terms of the infestation characteristics of the observed tick species, the drivers that may affect these characteristics, and the features of possible relationship between Hy. marginatum infestation in the cattle and CCHF cases among humans in the area.