Doctors at Hawke's Bay Hospital initially thought an infant with measles had the common cold as the illness can be difficult to diagnose in its early stages.
The family made two visits to the hospital's Emergency Department before the infant was diagnosed on Tuesday, July 16.
Three days before, the family had taken the infant to ED, and were sent home with what doctors believed was a cold as the infant was not displaying measles symptoms.
The infant had contracted the highly contagious airborne disease while visiting Auckland.
The infant was not old enough to be immunised against the virus.