2009 年 60 巻 4 号 p. 317-321
We reported a case of tsutsugamushi disease occurring in Yamagata Prefecture in Nov, 2007. A 70-year old man was admitted to the hospital for fever (38.9℃), skin rash, and an eschar on his neck. Laboratory examination of serum taken 14 days after onset of the illness showed elevated titers of antibodies against the Shimokoshi strain of Orientia tsutsugsmushi (IgG: 1:2,560; IgM: 1:5,120). The gene encoding the 56-kDa-protein specific for O. tsutsugamushi was detected by PCR from the patient's blood. Further sequence analysis of the PCR product (1,768 bpfragment including ORF region) revealed 99.4%, and 98.5% similarities to the Shimokoshi strain (Accession No: M63381) at the nucleotide and amino acid levels, respectively. Therefore, a very rare case of Shimokoshi-type tsutsugamushi disease was found in Yamagata Prefecture. Identification of the trombiculid species of vectors for this type of tsutsugamushi disease is needed in the future.