Things to look out for included flu-like symptoms of high fever, headache, confusion, sleepiness, joint and muscle pain, as well as more specific symptoms such as a rash, a stiff neck and an aversion to bright light. In babies the signs included crying and refusing to feed.
"If your child or someone in your family is not well, it's important to seek advice from your GP or, if they're very unwell, your nearest emergency department," she said.
Trained nurses could also offer 24-hour advice via Healthline on 0800 611 116.
Dr McLaughlin praised the family members involved for seeking medical advice quickly. Both children were recovering well, she said.
Kaeo Primary School principal Paul Barker said the older child became ill while at school last week. He called her father and urged him to take her to Whangaroa Health Centre, which he did straight away. The school was liaising with the family, he said.
On health board advice he sent a note home with the children on Friday. He also put a message on Facebook urging parents to keep an eye on their kids and to seek medical advice without delay if they had any concerns.
The school roll was down to about half yesterday due to various winter ailments and health centre staff were busy checking children, which Mr Barker took as a sign that people were being safe rather than sorry. He hoped the upcoming school holidays, which start on Friday, would give everyone a chance to rest and recuperate.
Meningococcal disease is caused by bacteria and can cause blood poisoning (septicaemia) or inflammation of the membranes around the brain (meningitis).
So far this year there have been three meningococcal cases in Northland , including the two in Kaeo and an average of two a year since 2012.
While the strain in Kaeo has yet to be identified, Northland DHB launched a mass vaccination campaign against meningococcal C in 2011 that saw 35,000 young people immunised free of charge. The campaign came after three young Northlanders died of meningococcal C in 2010.
The meningococcal B epidemic hit New Zealand in 1991. By 1992, 12 Northlanders had caught the deadly disease, and one died. At the epidemic's peak in 1997, 43 Northlanders were infected with two dying.
Anyone can catch the disease but it is more common in children under five, teens and young adults. It is spread by coughing or sneezing, kissing, and sharing drink bottles, eating utensils or toothbrushes. Covering the nose or mouth when sneezing or coughing and washing and drying hands helps reduce its spread. Treatment is by antibiotics.