Neuroinvasive West Nile Virus Infection in Kidney Transplantation: Three Case Reports

West Nile virus (WNV) is an emerging arbovirus in southern Europe, transmitted seasonally by vectors, with increased risk of severe forms in immunocompromised hosts such as kidney transplant recipients.

We report 3 cases of neuroinvasive WNV infection in kidney transplant recipients in Spain between June and September 2024. Demographic, clinical, microbiological, neuroimaging, treatment, outcome, and renal function data were collected.

All 3 patients developed neuroinvasive disease: 2 meningoencephalitis and 1 acute flaccid paralysis. Serum IgM was positive in all cases; cerebrospinal fluid (CSF) IgM in 2, and WNV PCR was positive in blood and urine in 1. Management included empirical antibacterial/antiviral therapy, reduction of immunosuppression, and intravenous immunoglobulin (IVIG) in 1 case. Outcomes varied: one patient fully recovered without sequelae, one had transient mild neurological deficits, and one developed irreversible neurological impairment and died after a prolonged hospitalization. Renal graft function remained stable in 2 cases, while one showed progressive deterioration during follow-up.

WNV is an emerging threat for kidney transplant recipients in Spain, associated with high morbidity, mortality, and neurological sequelae. Early diagnosis and tailored reduction of immunosuppression are essential, whereas the benefit of IVIG remains uncertain. Development of specific management protocols is needed in this high-risk population.