Fifteen patients have now tested positive for coronavirus at Craigavon Area Hospital as a third cluster was confirmed on site.
The outbreaks have prompted hospital authorities to suspend visiting for at least seven days in all but end-of-life circumstances.
The Southern Trust said a new cluster had been detected in one of the Co Armagh hospital's main wards, Ward 3 South, with one patient and one staff member testing positive overnight on Monday.
Eleven ward staff are self-isolating. The Haematology Ward and Emergency Department had already been tackling outbreaks. A total of 14 patients treated in the Haematology Ward have tested positive.