177. Clinical usefulness of the Eschar Polymerase Chain Reaction for Tsutsugamushi disease (Scrub typhus): A multicenter prospective study
Session: Poster Abstract Session: Diagnostic Microbiology
Thursday, October 18, 2012
Room: SDCC Poster Hall F-H
  • scrubTyphus_poster2012.jpg (706.7 kB)
  • Background:

    Tsutsugamushi disease (Scrub typhus) is a rickettsial infection caused by Orientia tsutsugamushi, gram negative intracellular bacteria, transmitted by young worm ticks. It has distributed not only in Japan but also in other Asian countries. Tsutsugamushi disease is clinically diagnosed by a typical rash, fever, and an eschar, and which made a definite diagnosis by serologic assays (indirect immunofluorescent test). However, it takes long time to obtain the result; usually after the treatment has already finished. Kim et al. showed that a PCR of eschar is useful for early diagnosis. The eschar PCR assay is a potentially useful test, since it does not require paired sample from convalescent phase. Thus, we designed a prospective study of PCR of eschar, since the sensitivity is still unknown in Japan.


    We conducted a multicenter prospective study of possible scrub typhus infection patients with eschar who came to Kameda Medical Center and Awa Regional Medical Center from October 2011 to February 2012. The eschar was submitted for nested PCR at Chiba Prefectural Institute of Public Health, and the results were compared with that of indirect immunofluorescent test. All eschar were collected the day or second day of admission.


    We prospectively studied 17 patients with scrub typhus. 16 patients were confirmed on the basis of either indirect immunofluorescent immunoglobulin M titer against Orientia tsutsugamushi of ≧1:40 or a ≧4-fold increase in the follow up titer. One patient was clinically suspected, but the pair serologic test had not performed.The nested PCR of eschar were positive 10 out of 17 patients (sensitivity; 58.8%).


    The eschar PCR assay was a useful test for definitive diagnosis, even though sensitivity was not high. Since the acquisition method of eschar has not standardized yet, there might be a variation of quantity of collected eschar, which resulted in lower sensitivity than expected. Standardization of the eschar sampling might be necessary before its widespread use.

    Eiichiro Sando, M.D.1, Tomoko Ogawa, D.V.M., Ph.D.2, Tokunin Fukushima2, Masanori Yosida, M.D.3, Rentaro Oda, M.D.1, Takashi Matono, M.D.1, Hisashi Shimozono, M.D.1, Takeshi Kimura, M.D.1, Akihiko Sotomatsu, M.D.1, Takaaki Kobayashi, M.D.1, Akiyuki Sato, M.D.1 and Makito Yaegashi, M.D., FCCP1, (1)General Medicine and Infectious Diseases, Kameda Medical Center, Kamogawa, Japan, (2)Division of Virology, Chiba Prefectural Institute of Public Health, Chiba, Japan, (3)General Medicine, Awa Regional Medical Centor, Tateyama, Japan


    E. Sando, None

    T. Ogawa, None

    T. Fukushima, None

    M. Yosida, None

    R. Oda, None

    T. Matono, None

    H. Shimozono, None

    T. Kimura, None

    A. Sotomatsu, None

    T. Kobayashi, None

    A. Sato, None

    M. Yaegashi, None

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