West Nile virus-associated meningoencephalitis in two chronically immunosuppressed renal transplant recipients.

West Nile virus is a mosquito-borne, single-stranded RNA virus of the Flaviviridae family. Approximately 1 in 150 patients who have serologic evidence of West Nile virus infection develop encephalitis or meningitis. We report two chronically immunosuppressed renal transplant recipients with confirmed West Nile virus meningoencephalitis acquired through community exposure. Both patients presented with fever and neurological changes in the autumn of 2002. Flavivirus-specific immunoglobulin M in antibodies in the cerebral spinal fluid and serum were detected by antibody-capture enzyme immunoassay, and antibodies for West Nile virus were confirmed by the plaque neutralization reduction assay. Reduction in immunosuppression and supportive care were successful in treating both patients. West Nile meningoencephalitis should be considered in transplant recipients that present with signs and symptoms of meningoencephalitis.