Just over 40 percent of people who have contracted measles this year have ended up in hospital.

Photo: AFP / nobeastsofierce / Science Photo Library

The latest figures from ESR (Institute of Environmental Science and Research) show 311 cases of the disease have been confirmed this year.

One hundred and twenty eight of those people have been hospitalised.

Babies are the group with the highest number of hospitalisations - 38.

In the past week, more than 20 new cases were registered in the Counties Manukau District Health Board, bringing the area's total to 100.

New cases have also been confirmed in Auckland, Waitemata, Taranaki and Wellington.

Last week, passengers on board an Air New Zealand flight to New Plymouth from Auckland were warned they may have been exposed to measles.