Characteristics of pediatric scrub typhus in a new endemic region of northern China

BACKGROUND: Scrub typhus emerged in northern China in 1986. Our objective was to document epidemiologic, clinical and laboratory features of pediatric scrub typhus in this new endemic area. METHODS: The pediatric patients diagnosed with scrub typhus during the 12-year period from 1995 through 2006 in Feixian County, Shandong province were enrolled in the study. The cases were diagnosed based on either specific antibody detection using the indirect immunofluorescent assay or detection of partial Orientia tsutsugamushi gene by polymerase chain reaction. RESULTS: Seventy pediatric scrub typhus cases were included in the study. The cases occurred from September through November. The common clinical manifestations included headache (100%), skin rash (91%), eschar (84%), lymphadenopathy (61%), and gastrointestinal signs (56%). None of the patients had neurologic involvement or thrombocytopenia. All children responded well to treatment with chloramphenicol. The patients who presented with abnormal chest radiography took significantly longer time to defervescence (Z[r] = 2.528, P = 0.011). Three strains of O. tsutsugamushi were isolated and all were identified as Kawasaki type. CONCLUSIONS: The manifestations of pediatric scrub typhus cases in the novel endemic region of northern China may be less severe than in other regions. Careful examination of skin eschars is helpful for the clinical diagnosis.