Lyme borreliosis is one of the zoonotic and vectorial diseases in the world. Female of Taiga tick, Ixodes persulcatus play an important role being the main vector of the agents, Borrelia burgdorferi sensu lato, of the
disease in the Far East including Japan. The number of patients who contacted
Lyme borreliosis have been estimated to be around 100 cases in all of Japan. We also detected the spirochetes from the skin tissues of 27 cases involving erythema and 3 cases without erythema after tick bites in Hokkaido. We noticed that in those cases when the victims removed ticks by themselves using their fingers within several days later, almost all of them developed erythema. On the other hand, an infected tick from 8 cases which were removed by surgical procedure, the spirochetes were not transmitted in these cases (No. 31-38). Therefore, we supposed that the transmission of agents takes place by regurgitation of the spirochestes from the midgut diverticula due to the pressure by fingers (calling Syringe phenomenon). Then, the authors recommended that fine tweezers has a firm grip around the mouth part of infested tick and pull out within 24 hours and/or trials to surgical operation for tick removal on passing over 24 hours after infestation.