The Zika virus is transmitted primarily through the bite of an infected aedes species mosquito, which can be found throughout the world. The virus was first identified in the Zika Forest in Uganda in 1947, but outbreaks have since been reported in southeastern and southern Asia, the Pacific Islands and the Americas.
When a mosquito bites a person infected with the Zika virus, the virus enters the mosquito. When the infected mosquito then bites another person, the virus enters that person's bloodstream.
The virus can also spread to the fetus during pregnancy.
Spread of the virus through sexual contact and blood transfusion have been reported.