Experimental infection of ticks Ixodes ricinus with tick-borne encephalitis virus under different microclimatic conditions.

The influence of environmental temperature and relative air humidity on the development of ticks Ixodes ricinus and their infection rate with tick-borne encephalitis virus was studied. It was found that the temperature influenced significantly the development of ticks, but it did not influence their infection rate. To the contrary, the relative air humidity influenced the infection rate. It is assumed that the intrinsic factors play a primary role in the infection of ticks, while extrinsic factors have a secondary role; they are probably important at border values only.