Clinical characteristics and outcomes in hospitalized patients with West Nile neuroinvasive disease: A case-series analysis

Background: West Nile virus (WNV) recently caused recurrent outbreaks in Europe and Italy, and the occurrence of neuroinvasive disease (WNND) was observed in less than 1% of cases, mainly older patients with several comorbidities. Due to the high mortality and post-infectious sequelae, the prognosis of this illness was frequently poor. Methods: In this case-series we reported the clinical outcomes of 7 patients hospitalized for WNND in the summer 2023 in our center of Infectious Disease in Vercelli, Italy. Results: Patients were generally older and affected by several comorbidities; at hospital admission fever and postural instability were most common symptoms; mortality rate observed was 42.8%; presence of neurological sequelae was detected in 28.6%. Diagnostic PCR for WNV was performed on cerebrospinal fluid (CSF) in 42.8% and urine sample in 57.1%. Treatment is supportive or with corticosteroids. Conclusion: WNND is a severe illness that may affect a vulnerable population especially in the summer period and requires a prompt diagnosis and knowledge of clinical characteristics and risk factors. Environmental intervention are required in the control of spread of mosquito vectors.