European health officials are reporting the first human West Nile virus case in a patient from Sofia, Bulgaria. The transmission season in Europe is from June to November.
The European Centre for Disease Control and Prevention (ECDC) says West Nile is an imported ‘tropical mosquito-borne disease’ but it has been present in Europe since the 1950s and is transmitted by local mosquitoes. Since 2010, when a large outbreak in Greece occurred, and implementation of close surveillance during the transmission season in 2011, hundreds of autochthonous (locally acquired) West Nile fever cases have been reported in Europe every year.
West Nile fever is a mosquito-borne disease, transmitted by the most common local mosquito species in Europe (Culex), which is found throughout Europe and is active during the summer. There is no vaccine or prophylaxis available, the only prevention is through avoiding and preventing mosquito bites.
Most human infections with West Nile virus are asymptomatic. Most people that get sick have mild, flu-like symptoms, lasting for three to six days – such as fever, headache and body aches. Weakness, malaise, anorexia, lymphadenopathy, nausea and vomiting could also occur. In rare cases the infection could lead to serious complications of the nervous system such as encephalitis, meningo-encephalitis or meningitis.