an emerging viral disease transmitted by Aedes mosquito bites - has been spreading in the Americas and the Caribbean, following the first cases reported in Brazil. The arrival of the virus has been associated with a steep increase in the birth of babies with abnormally small heads and in cases of Guillain-Barré syndrome. Based on a growing body of research, there is now a scientific consensus that Zika virus is the cause of microcephaly and Guillain-Barré syndrome (GBS). The magnitude of the risk that Zika virus infection during pregnancy will result in malformations in the foetus is under investigation, but remains unknown at present. As the spread of Zika virus disease continues in the American Region, the risk of Zika-infected travellers entering Europe increases. Imported cases of Zika virus infection have been reported in several European countries. However, at this stage, in the EU the virus has only been found in travellers returning from countries affected by the virus.