Segniliparus rugosus Infection, Australia

R. japonica is the specifi c pathogen of Japanese spotted fever, which has been found mainly in southwestern Japan (5). The present strain, closely related to R. japonica, is likely to have been isolated from H. hystricis in Thailand because R. japonica frequently has been isolated, or detected by PCR, from the same tick species in Japan (6). Such tick species–specifi city of SFGR should be considered when speculating on any geopathologic relationships of rickettsioses among different SFGR-endemic areas. Previous reports on spotted fever–positive results of human serosurveys (7,8) and on a clinical case (9) in northern Thailand may provide epidemiologic background. In Asia, multiple species of rickettsiea (e.g., R. japonica, R. heilongjiangensis, R. honei) are the causative agents of spotted fever rickettsioses, so the agent closely related to R. japonica could cause spotted fever in Thailand. Additionally, R. japonica has been found in Korea (10), and our current study indicates that R. japonica and its genetic variants are widely distributed in Far Eastern countries, including Japan (Grant-in-Aid for International Cooperative Research, unpub. data). Therefore, the epidemiology and genetic variation of SFGR throughout Asia should be examined by molecular studies.