Zika virus (ZIKV) is an arthropodborne member of the genus Flavivirus of the Spondweni serocomplex and is transmitted by Aedes mosquitoes (primarily Ae. aegypti in urban and periurban cycles). ZIKV emerged in Africa and has caused outbreaks of febrile disease that clinically resemble dengue fever and other arboviral diseases but has been linked to neurologic syndromes and congenital malformation. Outbreaks have been reported in the Yap islands of the Federated States of Micronesia, French Polynesia, and Oceania; Brazil is currently experiencing the first reported local transmission of ZIKV in the Americas.