Public Health Director, Naru Pal, said meningococcal disease can occur at any time of year but cases normally start to increase towards the end of flu season when people's immune systems are weaker from viruses.

"Last year South Western Sydney Local Health District reported 12 cases of meningococcal disease," he said.

"It is a rare but serious bacterial infection that can cause death within hours so the more symptoms people know about, the better.

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

A spokesperson for South Western Sydney Local Health Disctrict said that there had been no reported cases of meningococcal disease at Bowral and District Hospital in the last 12 months.

NSW Health's Director of Communicable Diseases, Dr Vicky Sheppeard said meningococcal can often mimic other common illnesses.

People should be aware as it gets closer to 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.

Meningococcal disease can affect anyone, however there are certain groups that are at higher risk. These include those who are in the same household with someone who has meningococcal disease, infants, small children, adolescents and young adults, people who have recently had a viral upper respiratory tract illness and travellers to countries with high rates of meningococcal disease.

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 years who miss the vaccine in school are eligible for a free vaccine from their GP.

There are several strains of meningococcal disease, and vaccination does not cover all strains, even vaccinated people need to be on the lookout for symptoms. The latest Annual Immunisation Report shows vaccination rates in NSW are at their highest level ever, with close to 95 per cent of five year olds fully vaccinated.