Tick-borne encephalitis in the Saarland and the Rhineland-Palatinate

The Saarland and the Rhineland-Palatinate are not considered endemic regions for tick-borne encephalitis (TBE), and patients in this region have not been routinely advised to undergo vaccination or serologic testing for TBE. In 1994, a significantly increased incidence of TBE cases was noted in the neighbouring state of Baden-Württemberg. In the same year, the first TBE acquired in the Saarland was diagnosed. To investigate the infection risk for TBE in the Saarland and Rhineland-Palatinate, the records of 2,123 serologic tests for TBE collected since 1989 were systematically examined. In addition, 904 frozen sera of patients displaying inflammatory changes in the cerebrospinal fluid (CSF) were analyzed. IgG and IgM antibodies against TBE virus were found in 15 patients, four of which were verified clinically and serologically as TBE. One of these four cases was certainly and another was probably acquired in the Saarland. Three other patients displayed serologic signs of a TBE virus contact. The results of this study suggest that the occurrence of single cases in the Saarland has to be considered, but the risk is very small.