The Department of Health says it has notified everyone who came in close contact with the first patient in Ireland with coronavirus.
It's after covid-19 was confirmed in Northern Ireland last night. It's the first confirmed case of the virus on the island of Ireland.
The female patient recently flew from Italy to Dublin, before travelling to Belfast. She is currently being treated in isolation at a hospital in Belfast.
Passengers who were sitting within two rows of the individual are considered to be most at risk.
Irish Rail says a deep clean of the full enterprise service, that runs from Dublin to Belfast, has been carried out as a precaution.
Dr. Michael McBride, Northern Ireland's Chief Medical Officer, says members of the public who have had casual passing contact with someone who is infected, need not be concerned;
"The risk of transmission is high only in those individuals who have had close personal contact, that's face-to-face contact, or in those individuals that have been within two metres of an individual for more than 15 minutes."
The HSE's Dr. Kevin Kelleher says there is a real concern that people who have symptoms won't contact health officials;
"They may or may not be symptomatic but even if they were symptomatic they may not thought it was an issue and even so some may never come to the system but they may have spread it. So that's why we are having such an active campaign to make sure people come forward."
Confirmed Cases Worldwide
More than 80,000 people, in nearly 50 countries, have been infected and close to 3,000 have died as a result of the virus.
Stock markets have fallen, as the impact of the outbreak is felt across the world. The Dow Jones recorded its biggest ever one-day points fall.
While the World Health Organisation has said that the outbreak has reached a "decisive point" and has "pandemic potential."
