The director of SNSWLHD public health unit, Tracey Oakman said, while the disease can occur at any time people's immune systems are weaker from viruses towards the end of flu season.

It is now less than a month until the peak period begins.

"Last year there were three meningococcal disease cases reported in the LHD, while the local numbers are low across the health district, it is important to remember that this rare but serious bacterial infection can cause death within hours so the more symptoms people know about, the better," said Mrs Oakman.

"Most cases occur in infants, young children, teenagers and young adults, although people of any age can be affected."

NSW Health's director of communicable diseases, Doctor Vicky Sheppeard said, meningococcal can often mimic other common illnesses, so it is important people be aware nearer spring that nausea symptoms, vomiting, neck stiffness, joint pain, light sensitivity, or a sudden fever, could be something else.

"Most people normally associate meningococcal disease with a rash of red-purple spots or bruises but in some cases, a rash doesn't appear, or it could be the last symptom to take shape," said Dr Sheppeard.

Meningococcal infection does not spread easily. It is spread by secretions from the nose and throat of a person who is carrying the bacteria. Close and prolonged contact is needed to pass it on.

"It more commonly occurs in people aged between 15-24 years as they tend to be involved in more intimate social activities such as kissing," said Dr Sheppeard.

Vaccination is the best means of protection against meningococcal disease. Vaccination for meningococcal disease types A, C, W and Y, is available on the National Immunisation Program for infants at 12 months of age and adolescents in Year 10.

Any adolescents aged 15 to 19 who miss the vaccine in school are eligible for a free vaccine from their GP. However, even vaccinated people need to be on the lookout for symptoms.