The Zika virus, which causes Zika, is spread by mosquito bites from infected insects, primarily from the Aedes species, to humans. People who travel or work in areas where Zika is present are at the greatest risk. Zika has been reported in South America, Central America and Africa, in addition to India. In the U.S., local Zika transmission has been seen in areas of Miami, Florida and Brownsville, Texas, in addition to U.S. territories like Puerto Rico, American Samoa and the U.S. Virgin Islands. The CDC maintains ongoing information about areas at risk of Zika.