West Nile virus meningoencephalitis and cytokines analysis: review and case report

West Nile virus (WNV) is transmitted via mosquito bites and causes ubiquitous zoonosis. Most infections in humans are asymptomatic, approximately 20% present as fever, and less than 1% as neuroinvasive disease. Central nervous system involvement is presented as meningitis, encephalitis, acute flaccid paralysis, or a combination of them. West Nile neuroinvasive disease (WNND) has a severe clinical course, potentially fatal outcome and frequent neurological sequelae in survivors. Risk factors for neurological impairment are advanced age and immunosuppression. Here we present a clinical case of meningoencephalitis caused by WNV and a brief literature review. Clinical and epidemiological data, laboratory, microbiological, molecular methods and imaging techniques were used. The cytokine levels of IL-6, IL-8, IL-10, IL-12(p40) and TNF-α in cerebrospinal fluid (CSF) and serum were also measured. We present a 55-year-old man with a sudden onset of headache, vomiting and fever. The symptoms appeared after a recent trip to Türkiye and involved multiple mosquito bites. Neck stiffness, disturbances in consciousness, signs of cerebral edema and subsequently focal neurological deficits were observed. The etiological diagnosis was verified by positive polymerase chain reaction for WNV and the presence of specific IgM antibodies in the CSF. After a 28-day hospital stay, the patient was discharged and referred to a Physiotherapy Unit due to residual motor deficits. WNV etiology should be suspected in patients with clinical and laboratory signs of viral neuroinfection, mosquito bites, and/or travel to endemic regions.