Volume 75, Issue 6
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645


The aim of this study was to evaluate the use of polymerase chain reaction (PCR) amplification of the 16S rRNA gene for the diagnosis of scrub typhus in rural Thailand. A prospective study of acute febrile illness in Udon Thani, northeast Thailand, identified 183 patients as having scrub typhus on the basis of immunofluorescent antibody testing (IFA) of paired sera. A further 366 febrile patients admitted concurrently with a range of other diagnoses acted as negative controls. Diagnostic sensitivity and specificity of 16S rRNA PCR was 44.8% and 99.7%, respectively, compared with IFA. PCR positivity was related to duration of symptoms and presence of eschar ( < 0.001, both cases). PCR using primers to amplify a fragment of the 56-kd gene had a sensitivity and specificity of 29.0% and 99.2%, respectively. PCR has a high specificity but low sensitivity for the rapid diagnosis of scrub typhus in this endemic setting.


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  1. Saah AJ, 2000. Orientia tsutsugamushi (Scrub typhus). Mandell GL, Bennett JE, Rodin D, eds. Mandell, Douglas and Bennett’s Principles and Practice of Infectious Diseases. Philadelphia: Churchill Livingstone, 2056–2057.
  2. Rosenberg R, 1997. Drug-resistant scrub typhus: Paradigm and paradox. Parasitol Today 13 : 131–132. [Google Scholar]
  3. Brown GW, Robinson DM, Huxsoll DL, Ng TS, Lim KJ, 1977. Scrub typhus: A common cause of illness in indigenous populations. Trans R Soc Trop Med Hyg 70 : 444–448. [Google Scholar]
  4. Bavaro MF, Kelly DJ, Dasch GA, Hale BR, Olson P, 2005. History of U.S. military contributions to the study of rickettsial diseases. Mil Med 170 : 49–60. [Google Scholar]
  5. Silpapojakul K, Varachit B, 2004. Paediatric scrub typhus in Thailand: A study of 73 confirmed cases. Trans R Soc Trop Med Hyg 98 : 354–359. [Google Scholar]
  6. Ogawa M, Hagiwara T, Kishimoto T, Shiga S, Yoshida Y, Furuya Y, Kaiho I, Ito T, Nemoto H, Yamamoto N, Masukawa K, 2002. Scrub typhus in Japan: epidemiology and clinical features of cases reported in 1998. Am J Trop Med Hyg 67 : 162–165. [Google Scholar]
  7. Coleman RE, Sangkasuwan V, Suwanabun N, Eamsila C, Mungviriya S, Devine P, Richards AL, Rowland D, Ching WM, Sattabongkot J, Lerdthusnee K, 2002. Comparative evaluation of selected diagnostic assays for the detection of IgG and IgM antibody to Orientia tsutsugamushi in Thailand. Am J Trop Med Hyg 67 : 497–503. [Google Scholar]
  8. Saisongkorh W, Chenchittikul M, Silpapojakul K, 2004. Evaluation of nested PCR for the diagnosis of scrub typhus among patients with acute pyrexia of unknown origin. Trans R Soc Trop Med Hyg 98 : 360–366. [Google Scholar]
  9. Singhsilarak T, Leowattana W, Looareesuwan S, Wongchotigul V, Jiang J, Richards AL, Watt G, 2005. Short report: detection of Orientia tsutsugamushi in clinical samples by quantitative real-time polymerase chain reaction. Am J Trop Med Hyg 72 : 640–641. [Google Scholar]
  10. Bozeman FM, Elisberg BL, 1963. Serological diagnosis of scrub typhus by indirect immunofluorescence. Proc Soc Exp Biol Med 112 : 568–573. [Google Scholar]
  11. Brown GW, Shirai A, Rogers C, Groves MG, 1983. Diagnostic criteria for scrub typhus: probability values for immunofluorescent antibody and Proteus OXK agglutinin titers. Am J Trop Med Hyg 32 : 1101–1107. [Google Scholar]
  12. Furuya Y, Yoshida Y, Katayama T, Yamamoto S, Kawamura A Jr, 1993. Serotype-specific amplification of Rickettsia tsutsugamushi DNA by nested polymerase chain reaction. J Clin Microbiol 31 : 1637–1640. [Google Scholar]
  13. Manosroi J, Chutipongvivate S, Auwanit W, Manosroi A, 2003. Early diagnosis of scrub typhus in Thailand from clinical specimens by nested polymerase chain reaction. Southeast Asian J Trop Med Public Health 34 : 831–838. [Google Scholar]

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  • Received : 25 Apr 2006
  • Accepted : 15 Aug 2006

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