Doctors around the world are looking for ways to help thousands of people in South and Central America and the Caribbean who have been affected by a disease called Zika.
The Zika virus is a disease which is spread by a type of mosquito found in some hot countries.
Zika is very unlikely to affect the UK, because the mosquitoes that carry the disease live in tropical countries and would find the UK too cold.
When people get Zika it usually doesn't affect them too badly - they feel a bit unwell, like they've got a cold.
But it's more serious if a woman is having a baby. Scientists say they think it may affect how a baby grows before it's born.
Doctors around the world are now coming up with ways to try to deal with Zika.
Martin has been looking into what it is and how to fight it...