[Prevalence of tick-borne encephalitis virus and rickettsiae in ticks of the district Burgenland, Austria].

Large areas of the Central European country Austria are known to be endemic for tick-borne encephalitis virus (TBEV). However, so far only limited data are available for the prevalence, distribution and species composition of rickettsiae of the spotted fever group in Austria. In the present study 306 ticks were collected in summer 2007. Location of sampling was Neudörfl, a known TBEV endemic area in the district of Burgenland in Eastern Austria. 286 ticks belonged to the species Ixodes ricinus and 20 ticks were identified as Dermacentor spp. Detection of TBEV and rickettsial species was done by polymerase chain reaction. We were not able to detect TBEV in any of the ticks examined. However 16 ticks, exclusively of the species Ixodes ricinus showed positive results for rickettsiae. 14 out of 16 rickettsia-positive ticks contains sufficient DNA for a sequence determination. The sequencing of the citrate synthase genes resulted exclusively in the identification of Rickettsia helvetica. The results show that TBEV was not at all or in a low frequency circulating in a known endemic area in summer 2007. However, for the first time the prevalence of 5.7% of Rickettsia helvetica was determined in a tick population in Eastern Austria.