Two ​Zika Virus Cases Have Been Confirmed in Sydney

NSW health authorities have confirmed two cases of Zika virus in Sydney. Both were detected by NSW Health last Friday, affecting a male and a female who had recently travelled to the Caribbean. NSW Health director of communicable diseases Vicky Sheppeard told the ABC that both patients contracted the virus in Haiti.

Dr Sheppeard told Sky News it is "very unlikely Zika virus will establish local transmission in NSW as the mosquitoes that spread the infection are not established here." These Aedes aegypti mosquitoes are; however, present in Far North Queensland, which may experience a small outbreak.

The Zika virus was first documented in Ugandan monkeys in the 1940s, with human cases found in Nigeria in 1960. The virus is carried from person to person by mosquito, similar to other diseases such as malaria and dengue fever. The first epidemic of Zika came in 2007, when 49 people were confirmed ill on the tiny island of Yap in Micronesia.

However, Zika didn't make global headlines until it hit Brazil in May 2015. In less than a year more than a million people have been affected. On 1 February 2016 the World Health Organisation (WHO) declared the virus a public health emergency, after it had spread to more than 20 countries throughout Central and South America.

The most common image of Zika is of babies born with microcephaly, a birth defect that causes a shrunken head and incomplete development of the brain. Researchers believe Zika may be linked to this condition, which also sprang up after an outbreak in French Polynesia in 2013. The Australian government has advised pregnant mothers to restrict travel to Zika-affected countries.

In the majority of cases Zika has no symptoms. Only around 20 percent of those affected experience a low fever, headaches, or a rash—all of which can appear up to 12 days after a bite and last for a week. However, some Zika cases in Brazil have been linked to Guillain-Barré, a condition that causes the body's immune system to attack its own nervous system.

Currently, there is no vaccine or cure for Zika. This is been attributed to a lack of attention from health authorities, who up until recently thought Zika posed little threat internationally. WHO has now called for better vaccines and testing processes, but such developments can take years.

Follow Maddison on Twitter.