Two people - including a child - have tested positive for Zika in Queensland as authorities around the world scramble to deal with the threat posed by the virus.

The child was diagnosed after presenting to a Brisbane hospital with symptoms following a family trip to Samoa.

It was the second case confirmed within 24 hours, with a woman diagnosed with Zika on the Gold Coast after returning from El Salvador in Central America where the virus is spreading.

The woman first saw a GP in mid-December and was told she had a Flavivirus, which includes dengue, yellow fever and Zika.

However she became ill again and recently presented to a Gold Coast Hospital, which ran further tests that confirmed she had Zika.

Mosquitoes (AFP) (AFP)

Queensland chief health officer Dr Jeanette Young said southeast Queensland wasn't at risk of Zika, despite two cases being confirmed in the region.

This is because the virus is predominantly transmitted to humans through the bites of infectious Aedes mosquitoes, most commonly Aedes aegypti, the same species that transmits dengue in north Queensland.

The two people infected have not travelled to north Queensland.

"I'm very confident that the two people we've just confirmed ... are no risk to anyone," Dr Young said.

Health Minister Cameron Dick said the cases showed the state's Zika detection systems were working and it was likely more Queenslanders would be infected.

"I expect that there will be more positive tests in Queensland - we need to be ready for that," he said.

Mr Dick said enhanced testing for Zika in Townsville, where the mosquitoes that can carry the virus are found, would begin on March 1.

He has also asked the health department to accelerate a $1 million education campaign highlighting the risks of Zika.

Queensland recorded three Zika cases last year, down from seven the previous year.

Mr Dick said all of those people were infected while overseas, and the virus had not taken hold in mosquitoes in north Queensland.

Those infected with Zika are most at risk of spreading the virus in the seven days after infection.

They are told not to travel to north Queensland where a mosquito could bite them and begin transmitting the virus.

Any north Queenslanders who became infected would be told to stay in air-conditioned rooms that mosquitoes couldn't access, Dr Young said.

Most infected people have no symptoms or experience only a mild illness but the virus has been linked to microcephaly, a neurological disorder in which infants are born with undersized heads.

Brazil has reported nearly 4000 suspected cases of microcephaly.