First West Nile fever case for 2015 transmission season found in Sofia, Bulgaria

Epidemiological update

​The first human case of West Nile fever (WNF) in the European region for the 2015 transmission season was reported on 23 June, in Sofia, Bulgaria.

First West Nile fever case in Europe in 2015
The first human case of West Nile fever (WNF) in the European region for the 2015 transmission season was reported on 23 June, in Sofia, Bulgaria.

The detection of a WNF case in Bulgaria is not unexpected: the country has previously reported cases and is surrounded by countries with reported cases in previous years.

The West Nile fever disease
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.

 
West Nile fever in Europe
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.
 
ECDC West Nile fever maps
In 2011 ECDC started to implement West Nile fever surveillance during the mosquito-transmission season in order to inform the blood safety authorities in Europe of areas in the EU and the neighbourhood with West Nile cases; according to EU legislation blood donors from such areas should be deferred or tested.
 
The West Nile fever weekly maps with the case data from Europe and the Mediterranean basin are updated online every Friday through an interactive web-based tool.
 
 
Weekly maps, updated 25/06/2015:West Nile fever weekly maps