[Tsutsugamushi disease during the last seven years in the past in Hamamatsu City, Shizuoka Prefecture--including evaluation of hyponatremia in scrub typhus].

Six cases of scrub typhus (tsutsugamushi disease) were reported to the Shizuoka Prefecture Hamamatsu City public health center during the seven years from 2001 to 2007. The content of the clinical record of the five cases were investigated. High serum titers of antibody to Gilliam-type Orientia tsutsugamushi were detected by immunofluorescense assay in most of these patients. Fever, rash, headache and relative bradycardia seen at a high frequency. On peripheral blood smear examination, atypical lymphocytes were detected in 3 cases. Serum electrolyte examination revealed hyponatremia in 4 (80%) patients; SIADH was suspected in one of these cases. All the patients improved promptly following start of therapy with intravenous or oral minocycline.