Isolation of a spotted fever group rickettsia from a patient and related ecologic investigations in Xinjiang Uygur Autonomous Region of China

Investigation of patients, healthy persons, and ticks in Jinghe County, Xinjiang Uygur Autonomous Region, People's Republic of China, for evidence of spotted fever group (SFG) rickettsiosis demonstrated strong evidence for a high prevalence of pathogenic SFG rickettsia. Antibodies to SFG rickettsiae were detected in 62.5% of healthy subjects tested by enzyme-linked immunosorbent assay and 20% tested by complement fixation test. Two febrile patients were documented as having acute spotted fever rickettsiosis by complement fixation seroconversion. One, an 11-year-old Kazakh boy with eschar and regional lymphadenopathy, had an SFG rickettsia (An strain) isolated from his blood. A hemolymph test revealed that 20% of ticks contained rickettsiae. Two strains of SFG rickettsiae were isolated from male and female Dermacentor nuttalli ticks. The human SFG rickettsial isolate is the first to be obtained in the People's Republic of China.