Dunedin Hospital has re-closed a ward as it continues to battle a serious outbreak of Norovirus.
The board's operations manager, Megan Boivin, on Sunday said only one person had been admitted with norovirus since Friday, and only four patients within the hospital had developed it.
The board says there were two new cases on Thursday, and four staff had developed symptoms.
The hospital severely restricted visiting and postponed more than 2,000 outpatient appointments last week when at least 160 staff and patients went down with the highly infectious virus.
It says a recurrence of an illness is not unusual after an outbreak, but it is reminding staff and the public about the importance of good hand hygiene.
The National Party on Thursday repeated its call for an independent investigation, so any lessons can be shared with other district health boards.
Ms Boivin says it has been decided to delay internal debriefings into the board's handling of the outbreak and no decision has been made on when they will start.
The health board says the air-conditioning in the ward block and clinical services building has been changed from recirculating air to bringing in fresh air and expelling air.
Health Minister David Cunliffe says he has full confidence in the DHB.