West Nile neuroinvasive disease. Report of four cases in Northern Greece, 2018

West Nile virus (WNV) is a mosquito-borne RNA flavivirus which caused several epidemics worldwide. The year 2018 was a WNV record year for Europe, including Greece, with earlier and longer transmission season with higher than the previous number of cases. It has been proposed that some simple biochemical markers may be helpful for the recognition of WNV neuroinvasive disease, its differential from other neurological infectious diseases and prognosis. We describe four cases that suffered from WNV meningitis and/or encephalitis hospitalized in 2018 in a tertiary hospital in Thessaloniki, Greece, and investigate the importance of simple biomarkers for the recognition of WNV etiology.