The latest case, a three-year old child from the Grafton area, is being treated in a Queensland hospital.
All close contacts of the person are receiving clearance antibiotics.
Symptoms of meningococcal disease are non-specific but may include sudden onset of fever, headache, neck stiffness, joint pain, a rash of red-purple spots or bruises, dislike of bright lights nausea and vomiting.
Meningococcal disease is very uncommon in NSW and two other cases have been notified in NNSW LHD this year, and only five cases for the whole of last year.
The disease is caused by a bacterial infection which is not easily spread from person to person and generally does not survive well outside the human body.
Vaccination against meningococcal C is included in the National Immunisation Program Schedule and is recommended for all children at one year of age (as part of free routine immunisation).
The NSW Government invested $13 million in a state-wide immunisation program for 2017-18 to combat a rise in the W strain of meningococcal disease.
In addition, the NSW Meningococcal W Response Program provided Year 11 and 12 students across the state with free vaccines that protect against four strains of meningococcal disease, A, C, W and Y in 2017. Year 10 and 11 students are being offered the vaccine in 2018. A single dose of this vaccine provides effective protection against all four strains for at least five years. This age group has been targeted as teenagers are very socially active and therefore both more likely to be exposed to the infection, and also more likely to spread the infection in the community.
It is important to note that meningococcal vaccines do not cover all strains of the disease, so even vaccinated people need to be aware of the symptoms. Anyone with symptoms is advised to see a doctor urgently.
For more information on Meningococcal see the NSW Health website
For further information, please call your local Public Health Unit on 1300 066 055.