Published Tuesday, 15 May 2012
More than 40 people have been struck down by the vomiting and diarrhoea bug over the past few days, including 30 patients and around 12 members of staff.
Hospital managers say they are hopeful the outbreak has now been brought under control with no new cases recorded on Tuesday.
However Unison says it has pushed an already stretched workforce to breaking point.
"This has put tremendous pressure onto staff at the Antrim Area Hospital," said Stephanie Greenwood, Unison Northern Health Branch Secretary.
They are having to take staff from uninfected wards to help cope in the wards where there is outbreak
"I've just taken a walk around the hospital and spoken to nurses in A&E, domestics, porters, pharmacy staff, nurses and they are all under horrendous pressure."
Some bed restrictions remain in place at the hospital, where affected patients have been isolated and the rate of cleaning at wards increased to twice a day.
Patients have also been asked not to bring in children who are under 12.
The Northern Trust says the outbreak is "slowing down" their ability to admit patients to the hospital's A&E and putting them under "considerable pressure".
Dr Peter Flanagan thanked staff for their efforts.
"We are having good progress and there have been no new cases overnight," he said.
"We had 30 patients yesterday, we now have 25 who are in the process of recovering from the illness while the number of wards affected is down from five to three.
"We want to thank the staff for all the hard work they have done in looking after the patients."
The hospital says it is working hard to admit patients amid challenging circumstances.
Meanwhile Unison chiefs are critical of how the outbreak was managed and claim that reduced staffing levels continue to leave this hospital vulnerable to further crises.
"The department today has been extremely busy," Ms Greenwood added.
"Staff have been at peak stress levels, under terrible workload pressures prior to this coming about - that is because of the closures at Mid Ulster hospitals and the staff are picking up these pressures."
© UTV News