CDC: Zika could affect 10,000 pregnancies in Puerto Rico by year's end [Video]

The Zika virus could affect up to 10,000 pregnant women in Puerto Rico this year, putting hundreds of babies at risk of catastrophic birth defects, according to the Centers for Disease Control and Prevention.

Zika is spreading so quickly on the island that it's likely to infect one in four people by the end of the year, CDC director Thomas Frieden said. The greatest danger from Zika is microcephaly, in which infants are born with abnormally small heads and incomplete brain development, he said.

"That's horrifying," Frieden said. "This is a silent epidemic that is rapidly spreading through Puerto Rico."

Liz Szabo
CDC: Zika could affect 10,000 pregnancies in Puerto Rico by year's end