Tests have been unable to confirm whether a Queensland resident has contracted Zika virus, health authorities say.
The Oonoonba local, who recently returned to Townsville from overseas, was suspected of being infected with Zika or dengue fever.
It prompted authorities to spray houses in Townsville to kill any mosquitoes potentially carrying the virus.
But on Monday, Queensland Health said it was not possible to tell what mosquito-borne virus the patient had because they had cleared the virus.
"The resident was only in Townsville for a couple of days while unwell, has now recovered and is no longer infectious," the department said.
"This means the chance of a disease being established in the mosquito that transmits dengue and Zika is low."
Only one type of mosquito, the Aedes aegypti, could spread either virus in Townsville, said Dr Steven Donohue, the Townsville public health unit director.
He said it was important residents knew how to eliminate the mosquito.
"The best way to do this is to spray in and around your home in dark hiding places with an ordinary surface or cockroach insect spray."
The mosquitoes lived in and around homes, had a short life expectancy, did not fly far and were likely to bite people on the feet during the day, he added.
"You may not even notice them."
Residents were urged to remove breeding sites from their properties by disposing of any containers that could hold water.
The department said anyone who was feeling unwell after visiting a country known to have Zika or dengue outbreaks needed to visit their GP as soon as possible.
