A fourth child has been hospitalised with meningococcal disease.
It follows the diagnosis of three other children with the potentially deadly disease on Sunday.
The first three diagnosed children, who are all related and aged under five, were diagnosed with the infection after attending New Year's Eve celebrations with family at South Bank.
The fourth child, an unrelated case, is a boy from South Brisbane who was admitted on December 31.
All four children are in a stable condition at Lady Cilento Children's Hospital.
On Wednesday, public health physician Megan Young said there was no increased risk to the general public of meningococcal disease.
"You need to be in close contact to be at increased risk of meningococcal disease and that does not include being in the same sort of general area," she said.
"However it is a timely reminder for parents to ensure children's vaccinations are up to date."
Dr Young said everyone who had been in direct contact with the three related children had been given antibiotics where appropriate.
"Those who had close contact with the children have been identified," she said.
"The strain of meningococcal disease has not yet been confirmed."
Symptoms of meningococcal disease are similar to the flu, and include high fever, a stiff neck, headaches, chills, and a purple rash.
The bacterial infection is spread through saliva from things like coughing, sneezing, and sharing food and drink, and can be fatal if left untreated.