2013–2014 Zika virus outbreaks in Oceania

In October 2013, there was an outbreak of Zika fever in French Polynesia, the first outbreak of several Zika outbreaks across Oceania. With 8,723 cases reported, it was the largest outbreak of Zika fever before the outbreak in the Americas that began in April 2015. An earlier outbreak occurred on Yap Island in the Federated States of Micronesia in 2007, but it is thought that the 2013–2014 outbreak involved an independent introduction of the Zika virus from Southeast Asia.

Investigators suggested that the outbreaks of mosquito-borne diseases in the Pacific from 2012 to 2014 were "the early stages of a wave that will continue for several years", particularly because of their vulnerability to infectious diseases stemming from isolation and immunologically naive populations.

The outbreaks spread across several island groups in the region. Following the initial French Polynesia outbreak, Zika spread to New Caledonia in late 2013 and reached the Cook Islands and Easter Island by early 2014. Subsequent cases were confirmed in the Solomon Islands, Vanuatu, and the Polynesia islands of American Samoa, Samoa, Tonga, and the Marshall Islands by 2015.

The Zika virus in Oceania was primarily transmitted by Aedes mosquitoes, particularly Aedes aegypti. A concurrent increase in neurological syndromes and autoimmune complications, including Guillain–Barré syndrome, was reported during the French Polynesia outbreak, and health authorities later noted an unusual rise in central nervous system malformations in fetuses and infants coinciding with the outbreak. Brazilian researchers have suggested that the Zika virus was subsequently introduced into Brazil from French Polynesia, contributing to the broader epidemic that began in 2015.