Zika virus continues to spread at ferocious rate
More than 3,000 pregnant women in Colombia have the mosquito-borne Zika virus, which is linked to birth defects.
The country's President has said the number of infections there could rise to as many as 600,000 by the end of the year.
Journalist James Bargent, who is in Colombia, has said much remains unknown about Zika.
“This is what people don’t really understand here is why this is spreading much faster than other mosquito borne diseases.
“And so researchers are really playing catch up with this virus, in terms of diagnostics.”
