Zika: Can fish help stop the spread of the virus?
9 February 2016 Last updated at 07:19 GMT
President Obama is asking the US Congress for more than $1.8bn in emergency funding to tackle the spread of the Zika virus.
The World Health Organisation has predicted there could be up to four million cases this year.
Some communities in El Salvador think they hold the key to stopping the spread of the Zika virus, as Katy Watson reports.