CENTRAL-NERVOUS-SYSTEM INVOLVEMENT IN PATIENTS WITH SCRUB TYPHUS

Scrub typhus, which is caused by Orientia tsutsugamushi, is a systemic illness that causes generalized vasculitis. The central nervous syste m (CNS) is the most crucial target in other rickettsial diseases; howe ver, there have been several reports of encephalitis or meningitis wit hout direct evidence of rickettsial invasion of the CNS in cases of sc rub typhus. To investigate CNS involvement in cases of scrub typhus, w e analyzed the CSF profiles (cell. count and levels of protein and glu cose) and amplified rickettsial DNA in CSF specimens by means of neste d polymerase chain reaction (PCR) for 25 patients with the infection. Mild pleocytosis was present in 48% of the patients: CSF white blood c ell counts ranged from 9 to 110/mm(3) (mean [+/-SD] count, 16.3+/-27.0 /mm(3)), and the mean (+/-SD) lymphocyte proportion was 51.98+/-23.9%. The CSF protein level was increased (>50 mg/dL) in seven patients. Ne sted PCR amplified six products from the 25 CSF specimens: four of the products were Boryong genotypes, and two were Karp genotypes. The res ults of this study suggest that O. tsutsugamushi does invade the CSF a nd that scrub typhus should be considered one of the causes of mononuc lear meningitis in areas of endemicity.