The spread of the Zika virus to South and Central America has been declared an international health emergency by the World Health Organisation (WHO) in the past week.

But it’s not just restricted to the Americas.

In Australia, a community health authority in north Queensland started instructing its citizens to take measures against the spread of the virus.

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This included removing standing water and making sure yards and outdoor areas were clean.

Last week, two Queenslanders – including a child – tested positive for the virus, and experts say there are likely to be more cases in Australia.

The child was diagnosed at a Brisbane hospital after returning from a family trip to Samoa, while tests at a Gold Coast hospital confirmed a woman, who first fell ill in December after returning from El Salvador in Central America, also had the virus.

Queensland Premier Annastacia Palaszczuk said the state’s health minister would be briefing Cabinet on Monday.

As Australia prepares for more potential cases, here is everything you need to know about the virus that has been linked to deformities in newborn babies.

How do people become infected?

The virus is transmitted to people through the bite of infected female Aedes mosquitoes, the same type of mosquito that spreads dengue, chikungunya and yellow fever.

The Pan American Health Organisation (PAHO) said Aedes mosquitoes are found in all countries in the Americas except Canada and continental Chile.

How do you treat Zika infection?

There is no treatment or vaccine available for Zika infection.

Companies and scientists are racing to develop a safe and effective vaccine for Zika, but one is not expected to be ready for months or years.

How dangerous is it?

The PAHO said there is no evidence that Zika can cause death, but some cases have been reported with more serious complications in patients with pre-existing medical conditions.

The virus has been linked to microcephaly, a condition in newborns marked by abnormally small heads and brains that have not developed properly.

It also has been associated with Guillain-Barre syndrome, a rare disorder in which the body’s immune system attacks part of the nervous system.

How is Zika related to microcephaly?

Health officials have yet to establish a direct causal relationship between Zika virus infection and birth defects, but it is strongly suspected.

Brazil has reported more than 4000 cases of suspected microcephaly that may be linked to Zika.

Researchers have identified evidence of Zika infection in 17 of these cases, either in the baby or in the mother.

What are the symptoms?

A baby believed to have been affected by Zika. Photo: Getty

People who get the Zika virus typically have a mild fever, skin rash, conjunctivitis, muscle and joint pain and fatigue that can last for between two and seven days.

But as many as 80 per cent of people infected never develop symptoms.

How can Zika be contained?

Efforts to control the spread of the virus focus on eliminating mosquito breeding sites and taking precautions against mosquito bites such as using insect repellent and mosquito nets.

US health officials have advised pregnant women to avoid travel to Latin American and Caribbean countries.

How widespread is the outbreak in the Americas?

Health officials said Zika outbreaks have been reported in at least 26 countries in the Americas.

Brazil has been the nation most affected. Other nations and territories include Barbados, Bolivia, Colombia, Costa Rica, Curacao, Dominican Republic, Ecuador, El Salvador, French Guiana, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Jamaica, Martinique, Mexico, Nicaragua, Panama, Paraguay, Puerto Rico, Saint Martin, Suriname, Venezuela and the US Virgin Islands.

What is the history of the Zika virus?

The Zika virus is found in tropical locales with large mosquito populations.

Outbreaks of Zika virus disease have been recorded in Africa, the Americas, Southern Asia and the Western Pacific.

The virus was first identified in Uganda in 1947 in rhesus monkeys and was first identified in people in 1952 in Uganda and Tanzania.

Can Zika be transmitted through sexual contact?

Some mosquitoes pass the Zika virus around. Photo: ABC

Two cases of possible person-to-person sexual transmission has been described, but the PAHO said more evidence is needed to confirm whether sexual contact is a means of Zika transmission.

What other complications are associated with Zika?

The WHO says because no big Zika outbreaks were recorded before 2007, little is known about complications caused by infection.

During an outbreak of Zika from 2013-2014 in French Polynesia, national health authorities reported an unusual increase in Guillain-Barre syndrome.

Health authorities in Brazil have also reported an increase in Guillain-Barre syndrome.