It was first discovered in Africa in the 1940s but is now spreading in Latin America
Scientists say there is growing evidence of a link to microcephaly that leads to babies being born with small heads.
The Zika virus can lead to fever and a rash but most people show no symptoms, and there is no known cure.
The only way to fight Zika is to clear stagnant water where mosquitoes breed, and protect against mosquito bites.
Zika was first detected in Uganda in 1947, but has never caused an outbreak on this scale.
Brazil reported the first cases of Zika in South America in May 2015.
Most cases result in no symptoms and it is hard to test for, but WHO officials said between 500,000 and 1.5 million people had been infected in Brazil.
The Zika virus has since spread to more than 20 countries in the region.
The US House Ethics Committee has voted to release its report on former Republican Representative…
ABC News has agreed to pay $15 million to President-elect Donald Trump to settle a…
South Korea’s parliament has voted to impeach President Yoon Suk Yeol over his failed attempt…
Israeli war planes have carried out more than 100 air strikes in Syria on December…
President-elect Donald Trump has threatened to impose 100% tariffs on the BRICS countries if they…
Syrian troops have withdrawn from the city of Aleppo following an offensive by rebels opposed…