Zika virus first discovered in African monkeys almost 70 years ago
The Zika virus was first identified in Uganda in 1947. According to the World Health Organisation (WHO), it was found in rhesus monkeys through monitoring for another virus and then identified in humans in Uganda and Tanzania in 1952.
Symptoms caused by Zika usually come on within a few days and include fever, skin rashes, conjunctivitis, muscle and joint pain, lethargy and headache.
WHO has said that during large outbreaks of Zika in French Polynesia (2013) and Brazil last year, national health authorities reported potential neurological and auto-immune complications.
The most recent concern focuses on babies born with microcephaly, although a direct causal link with Zika has not yet been established.
Microcephaly is a rare condition in which a baby's head is significantly smaller than the heads of other children of the same age. It is usually caused by failure of the brain to develop normally in the womb.
Pregnant women in particular are urged to take precautions against Zika-carrying mosquitoes.
These include wearing clothes (preferably light-coloured) that cover as much of the body as possible, using screens, closed doors and windows on buildings and sleeping under mosquito nets.
It is also important to empty, clean or cover containers that can hold water, such as buckets, flower pots or tyres, where mosquitoes like to breed.