Brazil recorded almost 4,000 cases in December
Officials in four Latin American and Caribbean nations have warned women to avoid pregnancy amid concerns over an illness causing severe birth defects.
Colombia, Ecuador, El Salvador and Jamaica recommended to delay pregnancies until more was known about the mosquito-borne Zika virus.
Meanwhile Brazil said the number of babies born with suspected microcephaly - or abnormally small heads - had reached nearly 4,000 since October.
US health authorities have now warned pregnant women to avoid travelling to more than 20 countries in the Americas and beyond, where Zika cases have been registered.