What is Zika virus?
Zika virus is a mosquito-transmitted disease. It was first isolated from a rhesus monkey in Uganda's Zika Forest in 1947.
The virus is common in West and Central Africa but also occurs in Pakistan, India, Vietnam,Thailand, the Philippines, Malaysia, Indonesia and Micronesia.
Only a few imported cases have been reported in Australia, with no locally acquired infections.
The virus has been linked to a devastating birth defect called microcephaly in which babies are born with abnormally small heads and brains that have not developed properly.
Travel concerns for Australians:
Eddie Bajrovic, the Medical Director for Travelvax Australia says Australians shouldn't change their travel plans.
"Zika virus generally is a mild illness so I wouldn't be suggesting that people change their travel plans except specifically for pregnant women because of this new association we've found between Zika virus infection and pregnant women and the foetal abnormality of microcephaly in their babies," he said.
The advice from Professor Christian Doerig, from the Department of Microbiology at Monash University in Melbourne is that travellers should always be very careful.
"It's always very good to be cautious about these things and since there are no drugs and no vaccine against this virus at the moment, the very best course of action is to protect yourself from mosquito bites," he said.
Advice from the Australian government:
The Department of Foreign Affairs and Trade's Smartraveller website has issued new advice on the fast-spreading Zika virus.
Australians, particularly pregnant women, are warned of the effects of the mosquito-borne virus on their unborn babies. Travellers are to reconsider plans to travel to 22 countries affected by the virus, including many in South and Central America, and the Pacific island nation Samoa.
"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. If you do decide to travel, talk to your doctor first and strictly follow steps to prevent mosquito bites during your trip", the statement warns.
World Health Organisation warning:
The World Health Organisation (WHO) says the Zika virus, linked to severe birth defects in thousands of babies in Brazil, is spreading rapidly. The WHO says it may infect 3 to 4 million people in the Americas, including 1.5 million in Brazil.
Director-general Margaret Chan has told members of WHO's executive board that the spread of the mosquito-borne disease had gone from a mild threat to one of alarming proportions.
"Last year, the virus was detected in the Americas, where it is now spreading explosively. As of today, cases have been reported in 23 countries and territories in the region," Ms Chan said, promising that the WHO would act fast.
Treatment for Zika virus:
There is no treatment or vaccine available for Zika infection. People who get Zika virus disease typically have a mild fever, skin rash, conjunctivitis, muscle and joint pain and fatigue, with symptoms normally lasting for two to seven days.
To avoid contracting the Zika virus, Eddie Bajrovic, the Medical Director for Travelvax Australia advises Australians to take similar precautions as avoiding other mosquito-borne viruses like dengue and chikungunya. "Use an appropriate insect repellent, cover up as much as possible with your clothing, " he said.
Mr Bajrovic adds that "pregnant people in particular probably shouldn't go to areas where there is a significant outbreak of Zika unless they really have to and if they do go then it's extremely important that they do take those mosquito precautions."
The United States says it has two potential candidates for a vaccine for the Zika virus.
The National Institute for Allergy and Infectious Disease says it may begin clinical trials in people by the end of this year, but there will not be a widely available vaccine for several years.