Pregnant women - or those planning to become pregnant - are being asked to take extra precautions and consider avoiding any travel to countries affected by the Zika virus.
The disease has been linked to a birth defect affecting babies brain development.
Meanwhile a case of Zika been confirmed in Denmark in a patient who had recently travelled to South America.
Relatively little is known about the Zika virus, as it was fairly rare until 2013.
This outbreak has spread to more than 20 countries in South and Central America, after first emerging in Brazil where it is been linked to an increase in incidence of a birth defect.
Professor of Biochemistry at Trinity College in Dublin, Luke O'Neill said: “This is transmitted by mosquitos and it is pretty benign actually, you get a bit of a flu, you are laid up for maybe a week and so on.
“But the trouble is if it infects women there is evidence that it causes a deformation, and the babies are born with smaller heads.”
There's no vaccine or treatment and Zika's symptoms are generally mild, with four out of five people unaware that they have caught it.
Here, the Department of Foreign Affairs and the Health Protection Surveillance Centre have issued guidance to Irish people travelling abroad.
Professor O'Neill says pregnant women or those planning a pregnancy should consider postponing any trips to affected areas: “The advice is and the advice in America is don’t travel to South America at the moment if pregnant.”
Meanwhile a Danish man who tested positive for Zika after a trip to Mexico and Brazil is expected to recover, and doctors there say there is no risk of the disease spreading.
