[Central nervous system infection--tick-borne encephalitis, neuroborreliosis or both?].

Certain tick species are able to transmit both tick-borne encephalitis (TBE) and Lyme borreliosis. Therefore, it is possible that a patient can simultaneously be infected with the TBE-virus and Borrelia burgdorferi-spirochete as a result of a single tick bite. Although this is a rare event, its possibility has to be taken into account e.g. in the diagnostics of febrile patients who suffer from symptoms typical of meningoencephalitis and who live or come from endemic tick regions. This is because the treatments of these two infectious diseases differ from each other--there is a specific treatment only for Lyme borreliosis. We describe two Finnish patients with double infection with TBE and neuroborreliosis.