Ein Fall einer autochthonen Frühsommermeningoenzephalitis (FSME) in Mecklenburg-Vorpommern

A 61-year-old man was bitten by a tick at Lake Woblitz, near the town of Neustrelitz in former East Germany. Nine days later he saw his general practitioner because of fever and headache. Three weeks after the tick bite he was hospitalized with fever (39.2 degrees C) and mental confusion. Because he had taken a Nile cruise six months earlier, malaria was considered and he was transferred to the department of tropical medicine and infectious diseases of the University of Rostock.The patient was somnolent, his speech was slurred, and he had amnesic aphasia, as well as impaired fine motor control, but no meningism, focal signs, pyramidal tract or sensory impairment. Cerebrospinal fluid (CSF) showed mild lymphocytosis (9,400 leukocytes per microL; 89% lymphocytes) and elevated protein concentration (1322 mg/L) with blood brain barrier impairment and intrathecal IgM synthesis. Anti-tick-bite encephalitis (TBE) antibodies (ELISA: IgG and IgM) were present in serum and CSF, and serum immunofluorescence showed an eight-fold titer increase within two weeks. These findings confirm the diagnosis of TBE. Other infections (including those with cross-reacting flaviviruses) were excluded by appropriate antibody testing.There is no specific antiviral treatment for TBE, but on symptomatic therapy the patient recovered fully within four weeks.The site of the patient's infection is located 10 km to the west of an old TBE focus, but no TBE virus had been detected there after 1975. The case demonstrates that TBE should be included in the differential diagnosis of meningoencephalitis, even if the patient has not been in an acknowledged TBE endemic area.