Health authorities have added eight tropical destinations to a travel alert – because of an illness linked to a severe birth defect, and spread by mosquitoes.
Abnormal brain development
The new locations are Barbados, Bolivia, Ecuador, Guadeloupe, Saint Martin and Guyana, Cape Verde, off the coast of western Africa, and Samoa in the South Pacific.
Last week's alert included Brazil, Colombia, El Salvador, French Guiana, Guatemala, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Puerto Rico, Suriname and Venezuela.
The CDC says pregnant women should consider postponing trips to these destinations because the virus has been linked with microcephaly. Affected newborns have unusually small heads and abnormal brain development.
All travellers to these areas are advised to take precautions, including using insect repellent and wearing long sleeves and long pants, to avoid mosquito bites.
Watch: What you need to know about the Zika virus
Zika illness can cause fever, rash and joint pain but most people infected by mosquito bites don't show symptoms. There's no specific treatment; infected people aren't contagious.
The CDC says people who do develop symptoms should tell their doctors where and when they travelled.