An Adelaide baby has died from meningococcal disease, one of five cases in SA in September.

A six-month old girl has died in Adelaide from meningococcal disease.

SA Health said she was one of five people diagnosed with the disease in September in South Australia.

The increase in cases has prompted SA Health's chief public health officer, Dr Stephen Christley, to remind people to be aware of the symptoms of the disease and seek medical advice if necessary.

"While fairly rare, meningococcal infection numbers tend to be higher when there are more respiratory infections around, such as influenza," he said in a statement on Thursday.

"Symptoms of meningococcal infection may include fever, headache, vomiting, stiff neck and sore muscles, followed in some cases by a rash of red and purple spots.

"Babies or young children with meningococcal infection may also be fretful, refuse feeds or be difficult to wake."

The five latest cases involved three children and two adults, aged between six months and 44 years.

So far in 2014 there have been 16 cases of meningococcal infection, compared to 17 at the same time last year.