West Nile virus in Europe: emergence, epidemiology, diagnosis, treatment, and prevention

Abstract

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.

Climate change impacts on West Nile virus transmission in a global context

“…Since then, new viral strains, probably of African origin, have increased human disease incidence in parts of Russia and southern and eastern Europe, with large outbreaks of increased clinical severity occurring in Romania, Russia, Israel and Greece [12,26].…”

“…These outbreaks in humans were accompanied by infections in donkeys in Bulgaria and horses in Morocco, Portugal, southern Italy and Greece. Since then, all subsequent years (2011 -2014) were characterized by the re-emergence of WNV in Europe, with human cases noted in almost all eastern, central and southern countries [23,26,72].…”

West Nile Virus: An Overview of its Recent Spread in the Mediterranean Basin

“…Most human and equine cases are asymptomatic. Nevertheless, nearly 30% of infected persons show symptoms ranging from a simple influenzalike syndrome to an encephalitis syndrome with a lethality rate of 17%, 10% of infected horses show neurological signs [4][5][6][7].…”

The role of Culex pipiens mosquitoes in transmission of West Nile virus in Europe

“…This was followed by reports of WNV cases in humans from France in the 1960s (Hubalek & Halouzka 1999, Murgue et al 2001. Since then, yearly recurring outbreaks have occurred in southern and central Europe, and WNV can now be considered endemic in the southern and central parts of Europe (Figure 1; Calistri et al 2010a, Sambri et al 2013). , or more specific distribution in Australia (lineage 1b), or India (lineage 1c).…”

“…To date, however, no cases of WNV have been detected in northern Europe, while WNV outbreaks occur in southern Europe (Calistri et al 2010a, Hubalek & Halouzka 1999, Reusken et al 2010b, Sambri et al 2013. The emergence of WNV in the United States of America (USA) after its introduction in 1999, has shown the potential of WNV to spread rapidly in a wide range of temperate climates (Davis et al 2005, Ebel et al 2004, Snapinn et al 2007).…”