FREQUENT ISOLATION OF FRANCISELLA-TULARENSIS FROM DERMACENTOR-RETICULATUS TICKS IN AN ENZOOTIC FOCUS OF TULAREMIA

A total of 924 questing Dermacentor reticulatus (Fabricius), 504 Ixode s vicinus (L.), sixty Haemaphysalis concinna Koch and 718 mosquitoes ( Aedes spp,) were examined in a floodplain forest ecosystem during the 1994-95 outbreak of tularaemia in South Moravia, Czech Republic. Franc isella tularensis was not isolated from H.concinna ticks or Aedes spp. mosquitoes, whereas twenty-one isolates were recovered from the other haematophagous arthropods. Dermacentor reticulatus revealed a signifi cantly higher infection rate (2.6%) than I.ricinus (0.2%). This tick s pecies acts as principal vector for tularaemia in the enzootic focus. Monitoring of D.reticulatus for F.tularensis thus seems to be a very e fficient approach in the surveillance of tularaemia in the flood-plain forest ecosystems of Europe.