Survey of ixodid ticks (Acarina: Ixodidae) and tick-borne spotted fever group rickettsiae in Tokunoshima Island, Japan

During the years 1991 to 1994, the fauna of ixodid ticks and tick-borne spotted fever group rickettsiae in Tokunoshima Island, one of the Nansei Islands in Japan was surveyed to clarify the epidemiological background of spotted fever group rickettsiosis on this Island. A total of 304 ticks collected were the following 4 genera and 8 species; Amblyomma testudinarium, Dermacentor taiwanensis, Haemaphysalis formosensis, H. hystricis, H. longicornis, H. pentalagi, Haemaphysalis sp. T and Ixodes granulatus. Of 90 ticks consisting of A.testudinarium, D.taiwanensis, H. formosensis, H. hystricis and H. sp. T examined for rickettsiae, A.testudinarium yielded 8 strains which were the first isolates from ticks in Tokunoshima Island. Serotyping showed that the present all isolates were the unclassified AT-1 serotype belonging to the spotted fever group isolated from A.testudinarium in Shikoku, Japan.