The First Case of Imported Relapsing Fever in Japan

Tick-borne relapsing fever (TBRF) is endemic in discrete areas throughout the world; however, a domestic or imported case of relapsing fever has not been reported in Japan. Here, we report the first imported case. A previously healthy 20-year-old woman presented to our hospital on October 8, 2010, because of recurrent fever and lower leg pain. Before consultation, she had experienced four febrile episodes at 10-12-day intervals after returning from her stay in Uzbekistan from 1 to 8 September. Giemsa stain of peripheral blood showed Borrelia spirochetes. The spirochete was identified as Borrelia persica by sequencing of the amplicons of flaB using polymerase chain reaction and phylogenetic analysis. The patient was diagnosed with TBRF, and she completed a 10-day course of minocycline 100 mg twice daily. After treatment, her periodic fever subsided. Physicians should be aware of TBRF in patients with recurrent fever who have returned from TBRF-endemic countries, including areas of the former USSR.