Updated travel advice on the fast-spreading Zika virus has been issued, with pregnant Australian women warned of the effects of the mosquito-borne virus on their unborn babies.
The Department of Foreign Affairs and Trade's Smartraveller website has added advice on Zika to a number countries in response to the "rapidly evolving situation".
DFAT is urging pregnant women to reconsider visiting 22 nations in the Caribbean, Central America, South America, Africa and the Pacific Islands where Zika is transmitted.
Previously, only five country advisories contained information about Zika.
"Recent outbreaks in Central and South America, particularly Brazil, have raised concerns that infection with Zika virus in pregnant women might cause certain birth defects," the Smartraveller website says.
The warning also applies to women who plan to become pregnant.
Zika has been linked to microcephaly, a neurological disorder in which infants are born with smaller heads.
Brazil has reported almost 4000 suspected cases of microcephaly, over 30 times more than had been reported in any year since 2010, according to the World Health Organisation.
Brazilian authorities have confirmed six cases of microcephaly in which the infant was infected with the Zika virus.
Zika has spread to 21 countries and territories in the Americas since May 2015 and is likely to spread to most countries in the region, WHO said.
The disease, which is transmitted by the dengue fever-carrying Aedes aegypti mosquito, has no vaccine or treatment and about 80 per cent of those infected show no symptoms.
DFAT warns travellers to take measures to prevent being bitten by mosquitoes and also advises people to be aware of transmission in nearby countries.
"Areas where Zika virus transmission is ongoing are difficult to determine and likely to change over time," it says.
COUNTRIES WHERE ZIKA IS TRANSMITTED
Barbados, Bolivia, Brazil, Cape Verde, Colombia, Ecuador, El Salvador, French Guiana, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Puerto Rico, Saint Martin, Samoa, Suriname, Venezuela.
*Source: Department of Foreign Affairs and Trade
