West Nile virus (WNV), a mosquito-borne flavivirus in the Japanese encephalitis 
antigenic group, has caused sporadic outbreaks in humans, horses and birds 
throughout many of the warmer regions of Europe for at least 20 years. 
Occasional cases of West Nile encephalitis have also been associated with 
infected blood transfusions and organ donations. Currently, WNV appears to be 
expanding its geographical range in Europe and causing increasing numbers of 
epidemics/outbreaks associated with human morbidity and mortality. This brief 
review reports on the current epidemic situation regarding WNV in Europe, 
highlighting the clinical, diagnostic and preventive measures available for 
controlling this apparently emerging human pathogen.