Officials in four Latin American and Caribbean nations have warned women to avoid getting pregnant amid concerns over an illness causing severe birth defects.
Colombia, Ecuador, El Salvador and Jamaica have recommended delaying pregnancies until more is known about the mosquito-borne Zika virus.
This follows an outbreak in Brazil where nearly 4,000 babies have been born with suspected microcephaly – or abnormally small heads.
Meanwhile, the US health authorities had warned pregnant women to avoid travelling to more than 20 countries in the Americas and beyond, where Zika cases had been registered.
Brazil is experiencing the largest known outbreak of Zika, with most cases in the north-east. Others have been detected in the south-east, an area which includes Rio de Janeiro and Sao Paulo.
There has been a sharp rise in the number of cases of Zika in several other Latin American countries.
In Colombia, more than 13,500 cases had been reported.
