Students at up to nine schools in Auckland have been infected with hepatitis A and health officials are calling on parents to stress to children the importance of hygiene.
By yesterday evening, up to 31 cases of hepatitis A in the region had been confirmed. The youngest is a 1-year-oldbaby and the oldest is 19.
The number of cases has been rising steadily over the past few days and it is thought there could be more.
Most of those affected are said to be primary and secondary school-aged children, but people have been infected across the region.
The Auckland Regional Public Health Service is investigating how the disease arrived in Auckland, but it is believed the likely source is a person or a number of people returning with it from overseas.
"It really is important to stress to parents that they don't have to be concerned in general, because the risk is assessed as being low," Dr Perera said.
"If parents do have children attending affected schools, they should be aware of the health information that is being sent home, so that they are aware of the potential symptoms."
Hepatitis A is a mild illness in children. Symptoms include general aches and pains, feeling generally unwell, loss of appetite and jaundice.
The disease can be spread from person to person or by eating or drinking contaminated food and water.
Officials are encouraging people to wash their hands thoroughly with soap and warm water regularly.
THE SYMPTOMS Generally feeling unwell. General aches and pains. Tiredness. Loss of appetite. Stomach upsets and pains. Diarrhoea. Nausea and vomiting. Dark urine Yellowing of skin and whites of the eyes (jaundice).
