INVESTIGATION OF HEMATOPHAGOUS ARTHROPODS FOR BORRELIAE - SUMMARIZED DATA, 1988-1996

Blood-sucking arthropods, collected in South Moravia, Czech Republic, were examined by darkfield microscopy for borreliae from 1988 to 1996. Among host-seeking ixodid ticks (8481 Ixodes ricinus (L.), 372 Dermac entor reticulatus (Fabr.), 167 Haemaphysalis concinna Koch), borreliae were only observed in adult (23.2%), nymphal (17.2%) and larval (6.3% ) 1. ricinus. The prevalence of borreliae in I. ricinus did not vary c onsiderably among habitats except for lower values in agroecosystems, xerothermic oak woods and grasslands. The frequency of intensity of sp irochaetal infection (log(10) counts of borreliae per tick) in I. rici nus approximated the negative binomial distribution. The proportions o f host-seeking female and nymphal ticks containing >100 borreliae were 5.0% and 1.7%, respectively. Among preimaginal ticks (749 1. ricinus, 222 D. reticulatus, 82 H. concinna) parasitizing free-living forest b irds and small mammals, borreliae were detected in 6.1% of larval and 10.3% of nymphal I. ricinus, and in one larval H. concinna; 3.2% of th e birds and 19.4% of the mammals carried infected ticks. Among 3464 fe male mosquitoes (Culicidae) of 6 species, 4.1% contained spirochaetes: 1.4% of Aedes vexans Meig., 1.3% of A. cantans (Meig.), 2.2% of A. st icticus (Meig.), 2.2% of Culex pipiens pipiens L. and 5.9% of C. p. mo lestus Forskal. Borreliae were also detected in 8.4% of 142 fleas (Sip honaptera, largely Ctenophthalmus agyrtes Heller and Hystrichopsylla t alpae Curtis) collected from small mammals. Twelve isolates of B. burg dorferi sensu late have been identified to genospecies: 6 strains from I. ricinus (4 Borrelia garinii Baranton et al., 1 B. afzelii Canica e t al. and 1 B. lusitaniae Le Fleche et al.), 1 strain from A. vexans ( B. afzelii), 2 strains from C. agyrtes (B. afzelii), and 3 strains fro m host rodents (B. afzelii).