The National Travel Health Network and Centre in the UK has issued advice for travellers to Europe and neighbouring countries, which shows that Europe has several native mosquito species capable of transmitting disease (e.g. Anopheles and Culex spp). In recent years, other mosquito species (e.g. Aedes spp) have become established in the region. The presence of these species increases the risk of locally acquired mosquito-borne diseases, previously never or rarely seen in Europe, occurring following importation from endemic countries. Travellers may be at risk of these diseases that include the chikungunya virus, dengue fever and dilofilariasis.
The Chikungunya virus (CHIKV) is a viral infection of humans and non-human primates transmitted by Aedes spp. mosquitoes. CHIKV is found in tropical and sub-tropical parts of Africa, the islands of the Indian Ocean, and South and Southeast Asia, and is an emerging disease in parts of Europe. Between July and September 2007, the first autochthonous (locally acquired) cases of CHIKV occurred in Europe in North Eastern Italy. There were 205 autochthonous cases with one death in this outbreak. The presumed index case was a local resident who developed a febrile illness shortly after returning from India to the region in June 2007. In 2010, two autochthonous cases of CHIKV occurred in the Var department, Provence Alpes Azur (PACA) region of France. Between May 2011 and July 2012, there were two imported cases and no autochthonous cases reported in the PACA region. Seasonal mosquito surveillance, control and obligatory reporting of suspected and confirmed cases is implemented in the PACA departments of Alpes de Haute Provence, Alpes-Maritimes, Bouches du Rhône, Corse du Sud, Haut Corse and Var. As of 7 July 2012, no autochthonous cases of CHIKV have been reported in the European Region.
In September 2010, two cases of autochthonous dengue were reported in Nice, France, which were the first cases to be reported in mainland France. Between 1 May and 13 July 2012, there were nine confirmed cases of imported dengue in the PACA region; there have been no further autochthonous cases since 2010. Seasonal mosquito surveillance, control and obligatory reporting of suspected and confirmed cases is implemented in the PACA departments of Alpes de Haute Provence, Alpes-Maritimes, Bouches du Rhône, Corse du Sud, Haut Corse and Var. In September 2010, a German tourist developed dengue after returning from the Pelješac peninsula and the island of Korcula in Croatia. In October 2010, a second case of dengue was reported in a female resident in the same area, who had not travelled outside Croatia. As of 7 July 2012, though, no autochthonous cases of dengue have been reported in the European Region during this year. Dirofilarial infection is an emerging zoonosis in parts of Europe including France, Hungary, Italy and Russia, with small numbers of human cases reported annually. Latvia reported two confirmed human cases in August 2011: the first reports of human dirofilarial infection in the country. Elsewhere, the National Travel Health Network and Centre has issued an update on levels of risk of mosquito-borne disease in the US. Travellers are advised that West Nile Virus (WNV), Eastern equine
encephalitis virus (EEEV) and dengue fever can all be found in the US, and that although the risk of contracting these diseases is low, individuals should still take necessary mosquito avoidance precautions, and bear in mind that levels of risk vary depending on destination and season.
As of 31 July this year there have been 241 reported cases of WNV, four of which were deaths, while one case of EEEV has been reportedin Florida. No outbreaks of dengue fever have been reported in the US in 2011 or 2012. No vaccines are available for these diseases.