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.”
The CDC also recommends that non-pregnant women with Zika should wait eight weeks before having sex.
Men and women who don’t have Zika but may have had possible exposure should wait eight weeks until trying to get pregnant to minimize the risk, the CDC said.
In addition, men and women living in an area where Zika is spreading should talk with their doctor about trying to get pregnant.
“These are very complex, deeply personal decisions,” Jamieson said.
Zika lasts in the blood for about two weeks, but scientists don’t know how long it lasts in semen.
“Unfortunately, there is still a lot we don’t know and a lot we need to know,” Jamieson said. “These recommendations are a best attempt to try and provide reasonable timeframes based on how well we know Zika persists in blood and how long.”
There are 273 Zika cases in 35 U.S. states and the District of Columbia. Almost all are from people who traveled to a country where the virus is spreading through mosquito bites, and the rest are from sexual transmission.
