Pregnant Australian women travelling to areas of Central and South America are being warned to take extra precautions against mosquitoes as concern about Zika virus spreads.
Recent outbreaks of the mosquito-born disease in a number of nations, including Brazil, been linked to serious birth defects such as microcephaly, which causes babies to have exceptionally small brains.
There is currently no vaccine to prevent Zika virus and no specific treatment. A number of public health approaches have been put forward as possible ways to halt the disease's outbreak.
In the wake of growing concerns about the fast-spreading disease, DFAT's Smartraveller website has extended advice on Zika to a number of "countries of concern".
It recommends pregnant women reconsider travelling to 22 nations in the Caribbean, Central America, South America, Africa and the Pacific Islands where Zika is transmitted.
The full list can be viewed here.
Previously, just five countries were on the Zika watch list.
"Until more is known about Zika virus, and taking a very cautious approach, we advise women who are pregnant (in any trimester) or who plan to become pregnant to consider postponing travel to any area where Zika virus transmission is ongoing," DFAT says.
"If you do decide to travel, talk to your doctor first and strictly follow steps to prevent mosquito bites during your trip.
"For those women who are pregnant and have recently travelled to areas where there is ongoing Zika virus transmission and suffered an illness that you think might be Zika, you should see a doctor."
DFAT says pregnant women heading to impacted regions should wear long sleeve shirts and long pants and use insect repellent, bed nets and screened-in rooms to avoid mosquito bites.
The World Health Organisation (WHO) warns that the outbreak is likely to spread throughout the Americas.
The impact of the illness can be difficult to pick up during pregnancy. One woman, whose baby shows signs of the effects of Zika, described her son's birth as the "worst day of her life".
James Cook University tropical disease expert, Professor Scott Ritchie, recently told AAP there was a real risk of an outbreak of the disease in Australia.
"The fact that we get dengue outbreaks means that this movement of mosquito-borne viruses does happen. So it's a real thing," Ritchie said.
He said a local outbreak of the disease would most likely be contained to northern Australia, where the Aedes aegypti mosquito is located.