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.
A strike by Brazilian health workers has been called off because of the ongoing battle against the Zika virus.
Union leader Sandro Cezar said the strike had been cancelled amid concerns it could affect the Brazilian people.
The union's members include workers who go door-to-door in Rio de Janeiro trying to eradicate the Aedes aegypti mosquito that transmits Zika.
The union had threatened to strike if the national health ministry failed to meet demands for better work conditions by Thursday.
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.