Two women from the suburbs of North Ward and Deeragun have been diagnosed with type two of the dengue virus - the first locally-acquired cases in the city since December, confirmed Queensland Health.
Dr Steven Donohue of Queensland Health said given the 10km distance between the two cases, it was likely more cases would come to light.
There certainly will be other cases - we are trying to find out what could be the link, he said.
One of the women had recovered and the other was still receiving treatment, said Dr Donohue.
They presented with very typical symptoms - sudden fever, severe headaches, muscle pains, nausea, he said.
Three Queensland Health teams and council officers are checking out properties to uncover mosquitoes and breeding sites, such as car tyres, saucers and pot plant stands.
Last year, the city experienced two small outbreaks which affected 13 residents.
Early last month, those outbreaks were declared over.