The team had been scheduled to enter the athletes' village on Wednesday, the day of the Games opening, but would remain at their training camp north of Brisbane, the New Zealand Olympic Committee said.
"She (Tui) is currently in isolation and being supported by a New Zealand team doctor who has travelled to the Sunshine Coast to be with her," the NZOC said in a statement.
Medical staff had told Games organisers of Tui's illness on Tuesday.
The team, who are one of the favourites for the gold medal in its debut at the Commonwealth Games, would remain on the Sunshine Coast until Sunday. The tournament runs from April 13-15.
The world champion men's All Blacks' 15s side had an outbreak of mumps on last year's end-of-season tour to the northern hemisphere.
All Blacks coach Steve Hansen said at the time he had been told by public health officials the combined MMR vaccine given to children who would now be aged between 20 and 30 had been less effective. Tui is 26.
"We wish Ruby a speedy recovery and will continue to prioritise her health and well-being, and that of the wider team," the NZOC added.
Games organisers said it was little wonder that some athletes would succumb to sickness.
"There are over 8,600 people living together and I can assure you that more people will get sick at some stage but they will be properly looked after," organising committee chief executive Mark Peters told reporters on Tuesday.
(Reporting by Greg Stutchbury; Editing by Amlan Chakraborty)
