Prevalence of Francisella tularensis in Dermacentor reticulatus ticks collected in adjacent areas of the Czech and Austrian Republics.

A total of 1098 host-seeking adult Dermacentor reticulatus ticks were examined in an active enzootic focus (floodplain meadow and forest ecosystem) of tularemia along the lower reaches of the Thaya (Dyje) river in South Moravia (Czech Republic) and adjacent Austria during the spring of 1996. Twenty-five isolates of Francisella tularensis were recovered (i.e., the overall minimum infection rate was 2.3%). The prevalence rate varied between 0.6% and 3.5% among four localities examined (two in Moravia and two in Austria) but the difference in the rate between Moravia (2.2%) and Austria (2.8%) has not been significant. The results show that D. reticulatus plays the role of an important vector in this extensive, perennial natural focus of tularemia.