[Another case of West Nile fever in the Netherlands: a man with encephalitis following a trip to Canada].

Shortly after his return to the Netherlands from a trip to Ontario, a part of Canada where infection with West-Nile virus has been reported, a 69-year-old man became increasingly confused and generally unwell, accompanied by fever. The clinical picture was compatible with viral encephalitis and this was supported by EEG findings and the results of the cerebrospinal-fluid examination. MRI of the brain did not contribute to the diagnosis. The patient was treated with aciclovir because herpes simplex encephalitis was suspected, and he recovered from his illness within a few days. The EEG normalised as well. The most important remaining symptom was diminished short-term memory function. After the patient was discharged, rising antibody titres against West-Nile virus were found in two consecutive sera; there were no antibodies to other encephalitis-causing viruses (such as Q fever virus and St. Louis encephalitis virus). This case report concerns the second imported case of West-Nile fever in the Netherlands and the first one with encephalitis.