Argasid ticks as possible vectors of West Nile virus in Israel.

Mites and soft ticks collected directly from wild and domestic birds and their nests were tested for the presence of West Nile virus (WNV). The cattle egret argas, Argas arboreus, was collected from the nests of seven cattle egret colonies. Out of 1,000 A. arboreus pools examined, 16 were positive for WNV based on RT-PCR technique. The positive pools were from four nesting colonies of birds. Out of 37 cattle egret squabs examined, 37.8% had serum-neutralizing antibodies to WNV. WNV RNA was also detected in one out of 15 pools of R. turanicus, in one out of 21 pools of O. sylviarum, and in one out of 18 pools of D. gallinae, while 63 pools of A. reflexus, 11 of R. sanguineus, and 30 of Hyalomma spec. were negative. The role of mites and ticks in maintaining the endemic state of WNV in Israel is discussed.