
Interagency science investigated environmental influences on Zika transmission and helped support response efforts.
In February 2016, the World Health Organization declared the Zika outbreak spreading across the Americas since 2015 a Public Health Emergency of International Concern, based on Zika’s previously-unknown association with birth defects. The virus was first discovered in 1947 in Africa and had not previously been found in the Western Hemisphere. By February 2016, the outbreak had spread to 48 countries and territories in the Americas...