Countries including South Africa and Trinidad and Tobago have confirmed their first cases of Zika virus.
More than 5,000 pregnant women in Colombia have contracted the virus, its government has said.
Three people died of Zika-related complications in Brazil last year, the country's health ministry said.
Britain's camp for the Rio Olympics should be moved to a Zika-free location outside Brazil, Jessica Ennis-Hill's coach has said.
The mother of Zika "bucket baby" Jose Ferreira is holding out hope despite doctors' fears over his future.
The government has told airlines to take the measure on all flights travelling to the UK from countries with confirmed transmission of Zika.