The flare-up of the highly contagious disease has affected dozens of children in schools and preschools in Wanaka and in surrounding towns.
Albert Town couple Cory and Rhonda Johnson were relieved their 22-month-old twin boys, Blake and Mitchell, were past the worst of their chicken pox in time for Christmas Day, but the toddlers still bear the spotty signs of the disease, which they caught from big brother Luke (4).
Mr and Mrs Johnson were aware, anecdotally, of a huge spike in chicken pox cases during the past few months at early childhood and primary school providers.
''I've heard that it's bad, and obviously we know other parents with kids with it,'' Mrs Johnson, a charge nurse at Dunstan Hospital, said.
The couple had isolated their three boys during their contagious phase to avoid spreading the infection any further.
Albert Town's Riverside Educare manager-owner, Dot Macfie, said at least 60% of the 100 children enrolled at the early childhood centre had recently been affected by chicken pox.
''It seemed to start from the schools because it was the kids who had older brothers and sisters, they were the first ones that came down with it,'' she said.
Wanaka Medical Centre practice nurse Stephanie Still confirmed there had been an outbreak of chicken pox in the Upper Clutha.
However, she was unable to provide any figures and said a lot of people would not visit their doctor with chicken pox.
Patients being treated for the disease were mostly under 10.
There is a vaccine for chicken pox, but it is not on the National Immunisation Register. Parents can have their children immunised at a cost of $72 for each of the two recommended doses.