Latin American health authorities and the World Health Organization are alarmed about the rapid spread of the Zika virus, which has been linked to birth defects.
Here are some key facts about the virus and the side effects it may cause, according to the UN health organization.
Where does the virus originally come from?
The Zika virus was first detected in 1947 in a monkey in the Zika forest of Uganda. For many decades, the virus lay dormant in monkeys and caused only occasional mild cases in humans.
How does the virus spread?
Zika is transmitted by Aedes mosquitoes, which are mainly found in tropical and subtropical regions. It is still not proven if there are direct pathways between humans, for example from mothers to their unborn babies.
What are the symptoms?
The virus usually causes only mild symptoms including fever, rashes, headaches and eye inflammations, similar to dengue fever. A quarter of those who are infected do not show symptoms. However, health experts suspect the virus is related to a sharp increase in babies born with abnormally small heads in Brazil, and in cases of Guillain-Barre syndrome, a neurological disorder that causes muscle weakness.
How did the virus get to the Americas?
The virus expanded to Micronesia in 2007 and to other Pacific islands in 2013 and 2014, causing large outbreaks. Chilean authorities first reported Zika transmission on the country's Pacific Easter Islands in 2014. The current outbreak in Brazil was first confirmed in May 2015.WHO expects Zika to be spread across all of the Americas eventually by mosquitoes.
What can be done to prevent infections and the spread of Zika?
WHO says people in affected areas should protect themselves by wearing light-coloured clothes covering most of the body, and by using insect repellant and mosquito screens. Women travelling to these regions should consult their doctor beforehand, and should get close medical monitoring if they are pregnant and could have been exposed to Zika. In addition, WHO called for spraying standing waters with larvicide and to remove water containers in order to eliminate mosquito breeding grounds.
What about vaccines and treatment?
There is currently no vaccine and no medication against the virus.