Three Brisbane children have been hospitalised with meningococcal disease after a family outing at a popular New Year's Eve event.

Brisbane residents are being assured they're not at increased risk of contracting meningococcal after three children who attended a New Year's Eve event were diagnosed with the disease.

The children, reportedly all aged under five, were admitted to the Lady Cilento Children's Hospital on New Year's Day.

They tested positive for the potentially deadly disease after spending New Year's Eve with family at the popular South Bank Parklands celebrations.

Queensland Health says the general public is not at increased risk of the disease as it is generally only spread after close, prolonged contact.

"You need to be a close contact to be at increased risk of meningococcal disease and that does not include being in the same sort of general area as a case," physician Dr Megan Young told reporters on Wednesday.

The incubation period is typically around seven days, but can be anywhere between three and 10 days.

All those identified as having close contact with the children had been contacted and provided with antibiotics where appropriate, Dr Young said.

It's believed the children are all related.

Health authorities have confirmed the trio are from the city's northside and became ill after an "extended family gathering" over the holidays.

They remain in hospital, with doctors still trying to determine the exact strain of meningococcal.

Dr Young said meningococcal sufferers typically spent a few days in hospital although that depended on the extent of their condition.

Meningococcal is a severe but uncommon infection that occurs when meningococcal bacteria invade the body from the throat or nose.

Close and prolonged contact with a person who has the bacteria in their nose or throat is usually needed for the bacteria to spread to others.

Symptoms in young children include fever, refusal to feed, irritability, grunting or moaning, extreme tiredness or floppiness, nausea or vomiting, diarrhoea, turning away from light, convulsions and rash of red or purple pinprick spots or larger bruises.