Survey of tick fauna and tick-borne pathogenic bacteria on Rishiri Island, off north Hokkaido, Japan

Tick fauna and tick-borne pathogenic bacteria were surveyed on Rishiri Island, off the northwest coast of Hokkaido, Japan. We collected Ixodes pavlovskyi and Ixodes persulcatus from vegetation, Ixodes angustus from Myodes rex, and Ixodes tanuki from Mustela itatsi and Felis silvestris catus. Borrelia garinii, the cause of Lyme disease in Eurasia, and Rickettsia helvetica and Rickettsia tarasevichiae of the spotted fever group were detected from I. persulcatus. These results indicate a potential threat of Lyme disease and spotted fever group rickettsiosis on Rishiri Island. It is possible that an introduced species, Mu. itatsi, contributes to maintenance of the infectious diseases as a blood source for the ticks on the island.