[Double infection with early summer meningoencephalitis virus and Borrelia burgdorferi].

A 68-year-old woman developed a meningoencephalitis 18 days after a tick bite. IgG and IgM antibodies against tick-encephalitis virus were demonstrated, by enzyme-linked immunoabsorbent assay, in both serum and cerebrospinal fluid (csf). Lymphoplasmocytic pleocytosis was present in csf for over six weeks, as was an increased IgM level. Three weeks after the onset of neurological symptoms and clearing of the encephalitis there occurred multiple peripheral pareses in the left leg which were slow to regress. Retrospectively, IgM and IgG antibodies against Borrelia burgdorferi were demonstrated in deep-frozen serum and csf. Since IgG antibodies against Borrelia burgdorferi, locally synthesised in csf, could also be demonstrated, it must be assumed that the patient had a double infection. It is suggested that in confirmed cases of tick-encephalitis with an atypical course an additional infection with Borrelia should be considered, because if present the latter can be successfully treated with high doses of penicillin.