The national rate of people being hospitalised for rheumatic fever has dropped further than officials thought it would.
The rate went down to 3.4 cases per 100,000 people last year, better than the Ministry of Health's earlier provisional rate of 3.9 cases.
The Northland and Midland regions continue to have the highest numbers and rates of rheumatic fever hospitalisations.
In Northland, 15 people were admitted to hospital with the disease last year.
The region's Medical Officer of Health, Clair Mills, said her area was not on top of rheumatic fever.
Dr Mills said the region had continued to have relatively stable numbers, and could not say from a decrease over a couple of quarters that they had suddenly fixed the situation.