A pregnant Queensland woman has tested positive to Zika virus after recently returning from overseas, Queensland Health has confirmed.

The woman was diagnosed in south-east Queensland yesterday and authorities said the illness was not acquired locally.

It is the third case of Zika virus to be identified in Queensland this year.

No further information will be released on the pregnant woman.

However, Queensland Health said it was a separate case from that of a woman who returned to the Gold Coast from El Salvador in December, who had also tested positive to Zika last week.

Zika is a mosquito-borne illness that has surged through Latin America and has been linked to birth defects in children in the region.

However, a four-year survey in Brazil suggested Zika may not be the cause of microcephaly, which results in babies being born with abnormally small heads.

A statement from Queensland Health said the Federal Government recommended that until more was known about Zika virus, women who are pregnant or those actively seeking to get pregnant should consider postponing travel to any area where Zika virus transmission is present.

Pregnant women who have recently travelled to areas affected and suffered an illness they suspect to be Zika are advised to see a doctor.

The Federal Government has compiled a full list of the relevant countries.

The World Health Organisation (WHO) has declared Zika virus to be a public health emergency of international concern.

WHO says symptoms are usually mild and normally last two to seven days.

Symptoms are similar to dengue and chikungunya and include:

a mild fever

a mild fever skin rash

skin rash aches and pains

aches and pains headache

headache conjunctivitis

About one in five people infected with the virus become ill. Zika virus usually remains in the blood of an infected person for about a week.

For the virus to spread in Australia, it would need the right species of mosquito to act as a vector.

Australian virologists say only one such mosquito is present in Australia — the Aedes aegypti mosquito — which is found only in far north Queensland.

Authorities have said the threat of an outbreak of Zika virus in Australia is low, but they are still ramping up tests for the virus, including opening a special pathology centre in Townsville to rapidly test for the virus in humans.

A vaccine for the Zika virus is still years away, US health officials have warned.