A major health alert is under way after it emerged that a former employee of a hospital in Northern Ireland had infected two patients with the Hepatitis C virus.
Tests are being offered to women in Northern Ireland who were treated at the maternity and gynaecology unit in the Mid-Ulster Hospital between January 11 and November 4 in 1979.
The Northern Trust is inviting anyone who attended during the 11-month period to get in contact.
Hepatitis C can affect the liver but in most cases there are no noticeable symptoms until the liver has been significantly damaged.
Health officials have said that transmission through contact with an infected healthcare worker is extremely rare and will only happen if they lead, or assist in, an operation on a patient.
The health worker only worked in one hospital in Northern Ireland but worked in 11 in England between 1975-1983.
Public Health Wales revealed two patients are known to have contracted the virus from the employee while they worked at a hospital in Wales from 1983 before moving on in 2002.
Dr Robin Ashe, clinical director for obstetrics and gynaecology at the Northern Trust said that people should not be "overly alarmed" and emphasised that the Trust is "just being very cautious".
He said: "The risk of transmission of Hepatitis C from a health care worker to a patient or someone working along side them is extremely low."
Anyone who is concerned is asked to contact a helpline set up by the Northern Health and Social Care Trust on 028 9442 4804. The line is open seven days a week from 8.30am to 8.30pm.