WELLINGTON, Sept 12 - Adults and children at the school are being asked to check their immunisation status after the case was confirmed on Tuesday.

"Mumps is a highly infectious viral infection, spread by breathing, sneezing and coughing," says Medical Officer of Health Dr Rachel Eyre.

"People with mumps may suffer swelling of testicles or ovaries, hearing loss, breathing difficulties and rarely, brain inflammation."

"It can affect babies, children or adults."

"If you suspect you or your child is developing a fever or has swelling of glands around the cheeks or jaw, phone your own doctor or Healthline," Eyre said.

"Please stay away from school, work or community gatherings until five days after swelling develops or until well, whichever is sooner." 

A letter has gone to staff and parents at the school advising them that if they aren't immune, there is a risk of passing the infection on to others even before developing symptoms.