Health agencies in Auckland are being told to watch out for cases of rubella following two diagnosed cases in the past week.
Two men in their 20s have contracted the virus, which is also known as German measles.
Medical Officer of Health Richard Hoskins says the illness is usually mild, but is particularly dangerous for pregnant women and their unborn children.
Dr Hoskins also says a measles outbreak in Auckland has now reached 109 confirmed cases.
Meanwhile, Waikato District Health Board is dealing with 19 confirmed cases of measles and one probable case. All the cases are teenagers.
