An evolving outbreak of Zika virus infections is currently spreading in the Americas and the Pacific region.
Possible links between Zika virus infection in pregnancy and microcephaly have been under investigation since October 2015, when the Brazilian Ministry of Health reported an unusual increase in cases of microcephaly after Zika virus outbreak. French Polynesia reported an increase in cases of central nervous system malformations during 2014–2015 following the Zika virus infection. Investigations of a link between Zika virus infection and Guillain–Barré syndrome are also ongoing in affected countries.
On 1 February 2016 WHO declared a Public Health Emergency of International Concern (PHEIC) regarding clusters of microcephaly cases and neurological disorders in some areas affected by Zika virus.