Ticks biting humans in the urban area of Istanbul

Abstract

A passive surveillance for tick bites in humans was undertaken in the city of Istanbul (Turkey) in the summer and autumn of 2006. From 1,054 reported tick bites, most were females of Ixodes ricinus (27%) and nymphs of Hyalomma aegyptium (50%). A few adults of Hyalomma m. marginatum, Rhipicephalus sanguineus and Dermacentor marginatus were also recorded. We investigated potential risk factors for I. ricinus and H. aegyptium with spatial statistics. Climate features at 1-km resolution (monthly minimum temperatures in late summer and autumn and rainfall) and vegetation features at high resolution (density and heterogeneity of forest-type vegetation as well as distance of reporting site to these vegetation features) are useful variables explaining high reporting clusters for both Ixodes and Hyalomma. While Ixodes is highly reported in dense highly heterogeneous vegetation patches, Hyalomma is commonly found in areas far from forest-type features and in the small, relatively dry vegetation patches within the urban fabric.