The unpredictable nature of battling the highly contagious stomach bug norovirus has seen one ward at Dunedin Hospital reopen and another close since yesterday.
The geriatric health ward, 6B, has been closed after three patients and one staff member became ill with vomiting and diarrhoea.
Orthopaedic ward 3C, which was closed on Monday with confirmed cases of norovirus, reopened yesterday.
Wellington's Hutt Hospital, which confirmed this week it was battling the bug, has had no new cases since yesterday.
From a peak of 11 cases earlier in the week, there were only five people who were still unwell, spokesman David Graham said.
Restrictions on admissions and visitors to the two medical wards were still in place. Surgery was unaffected and medical admissions were being accommodated in other wards.
Decisions on how to handle the long weekend would be made later today, he told NZPA.
Dunedin Hospital was badly hit by an outbreak of the virus in August, which, at its worst, affected more than 170 staff and patients.
Ironically, this week is Infection Prevention Week and senior staff at the hospital spent yesterday morning learning what was involved in a "terminal clean".
ISS hospital services manager Heather Fleming said a terminal clean involved removing everything portable from the room, such as linen and curtains, for washing, and medical equipment for sterilising, as well as cleaning every surface, including mattresses, cupboards and windows, with bleach.
The detailed scrubbing is needed in every room which has housed an infectious patient before another one can move in.
It normally takes four people an hour to complete a terminal clean. During the Dunedin outbreak 1400 hours of cleaning was clocked up.