Biosecurity

Men with Zika: No sex for six months, CDC says

Men who have the Zika virus should hold off on having sex for at least six months, the federal government said Friday, as the number of U.S. cases as grown to nearly 300.

The new recommendations from the Centers for Disease Control and Prevention comes as scientists still don't know how long the Zika virus, which is linked to the birth defect microcephaly, lasts in semen. The new recommendations reflect a shift by the CDC to focus on the period of conception.

"Previously, we were really focused on protecting pregnant women and our recommendations were around women who were already pregnant," said Denise Jamieson, co-leader of the pregnancy and birth defects team for CDC's Zika Virus Response team, on a call with reporters. "Before it was just women who are currently pregnant."