At present, dengue is frequently introduced into Europe by travellers returning from dengue-endemic countries. The recent re-introduction and transmission of the dengue virus – with locally transmitted cases reported in France and Croatia in 2010, and in Madeira, Portugal in 2012 – showed that transmission is possible in different areas of continental Europe where Aedes albopictus or Ae. aegypti are present.
The chikungunya outbreak in Italy in 2007 proved that Europe remains vulnerable to transmission of other tropical arboviruses and confirmed that Ae. albopictus is capable of supporting local transmission. The notification of sporadic cases in France in 2010 showed that favourable conditions for transmission exist in other areas of Europe where Ae. albopictus is present.