Zika virus is a rapidly emerging vector-born flavivirus, with potential to spread to new areas where the vector Aedes mosquitos are present.
In May 2015, autothchronous circulation of Zika virus was confirmed in 2 Brazilian states. In October 2015, Brazilian health officials from the state of Pernambuco reported an unusual increase in the number of cases of microcephaly in newborns, and on 11 November 2015, the Ministry of Health declared a public health emergency, establishing an emergency operations centre and deploying surveillance and response teams. Zika virus is now confirmed to be circulating in 21 states, and is estimated to have infected between 440,000 to 1,300,000 people in Brazil in 2015.
As of 23 January 2016, 4,180 cases of microcephaly have been reported from 21 Brazilian states – more than a 20-fold increase compared to the average number of annual cases reported from 2010-2014.
Between 19 November 2015 and 19 January 2016, 23 countries reported autochthonous cases of Zika virus infection: Barbados, Bolivia, Brazil, Cape Verde, Colombia, Ecuador, El Salvador, French Guiana, Guadeloupe, Guatemala, Guyana, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Puerto Rico, Saint Martin, Samoa, Suriname, Thailand and Venezuela.