The World Health Organization calls the spread of the Zika virus "explosive". It estimates up to 4 million people in the Americas could be infected over the next 12 months.
It's not yet confirmed but health officials believe it may affect unborn babies resulting in smaller heads and incomplete brain development or Microcephaly.
Brazil is the hardest-hit nation with over 4,000 cases of birth defects reported.
And while there is no treatment or vaccine, the race is on to find one; but that could take years.
So what can be done to contain the Zika virus?
Presenter: Fauziah Ibrahim
Nathalie MacDermott - Pediatrician, Imperial College London.
Jonathan Ball - Professor of Molecular Virology, Faculty of Medicine & Health Sciences, University of Nottingham.
Derek Gatherer - Virologist, Lancaster University
Source: Al Jazeera