Kasuya S, Koga K, Hioki A, Nagano I, Yamashita T, Ohtomo H, Iwasa M, Noda N
Department of Parasitology, Gifu University School of Medicine.
Kansenshogaku Zasshi. 1991 Feb;65(2):151-6. doi: 10.11150/kansenshogakuzasshi1970.65.151.
Investigations of trombiculid mites and Rickettsia tsutsugamushi in wild rodents were made in Ena (Nov. 1988) and Takayama (May 1989) City. In the former area where no patient has been reported so far, Leptotrombidium pallidum (63.9%) was most predominant and no L. scutellare was found. A Karp-related rickettsia (11.1%) was isolated from wild rodents and 30% of them had antibody to R. tsutsugamushi (anti-Karp was prominent). The latter area where patients were reported in spring as well as in autumn, L. pallidum (22.4%) was one of the dominant species in spring. Karp-related strains were isolated from 37.5% of wild rodents. And the antibody possession rate was 50.0%. These data reconfirmed our hypothesis that the majority of patients in autumn were infected by L. scutellare and a part by L. pallidum. In spring in Takayama area, the vector was L. pallidum which possessed Karp-related strain(s).
1988年11月在伊那市以及1989年5月在高山市对野生啮齿动物中的恙螨和恙虫病立克次体进行了调查。在伊那市（到目前为止尚无患者报告），苍白纤恙螨（63.9%）最为常见，未发现小板纤恙螨。从野生啮齿动物中分离出一株与Karp株相关的立克次体（11.1%），其中30%的动物有恙虫病立克次体抗体（以抗Karp抗体为主）。在高山市，春秋季均有患者报告，春季苍白纤恙螨（22.4%）是优势种之一。从37.5%的野生啮齿动物中分离出与Karp株相关的菌株，抗体携带率为50.0%。这些数据再次证实了我们的假设，即秋季的大多数患者是由小板纤恙螨感染的，部分患者是由苍白纤恙螨感染的。在高山市春季，传播媒介是携带与Karp株相关菌株的苍白纤恙螨。
