Improvement in early diagnosis of Japanese spotted fever by using a novel Rick PCR system

Rickettsia diseases, including Japanese spotted fever ( JSF ), are serious infections. Delayed diagnosis occasionally results in life‐threatening liver disorders and disseminated intravascular coagulation ( DIC ). Because of the shortness of the latent period, serological diagnosis is not preferable for early diagnosis of JSF . Until now, a polymerase chain reaction ( PCR )‐based diagnosis method has been used for early diagnosis, and the sensitivity reaches as high as 90% using skin biopsy samples as we previously reported. On the other hand, the sensitivity of the same PCR method using blood samples is limited at less than 50%. In the present study, using peripheral blood samples, we developed a novel diagnostic method for JSF using a Rick PCR system with original PCR primers, showing improved sensitivity compared with the conventional nested PCR . It may constitute a preferable diagnostic tool for early and sensitive diagnosis of Rickettsia infection.