Why the CDC Is Urging Some Pregnant Women to Abstain From Sex

The CDC has a strong recommendation about this. (Image: Getty/Yahoo Health)

The Centers for Disease Control and Prevention has a bold new recommendation for pregnant women regarding the Zika virus: Change your sexual behavior if your partner has visited a Zika-infected area.

“Until we know more, if your male sexual partner has traveled to or lives in an area with active Zika virus transmission, you should abstain from sex or use condoms the right way every time you have vaginal, anal, and oral sex for the duration of the pregnancy,” the CDC said in a press release issued Wednesday.

Zika virus, largely a mosquito-borne illness, has been linked to brain damage in newborns after more than 4,000 babies were born in Brazil in the past year with unusually small heads, an incurable condition known as microcephaly. In early February, the World Health Organization called the rapid spread of the virus a global health emergency.

Related: Is This Mosquito Repellent Your Best Protection Against Zika Virus?

But the link between Zika virus and sexual contact is growing. Research suggests that Zika may be found in semen after it disappears from the blood, and there have been at least two reported incidents of sexual transmission in the U.S. One was an American man who transmitted it to his wife after contracting the virus in Senegal in 2008; the other, which was reported this week, occurred in Texas after an unidentified patient who visited Venezuela spread the virus to a sexual partner.

“We’re learning a lot about Zika as we go along and just recently have become convinced that Zika can be transmitted sexually,” William Schaffner, MD, an infectious-disease specialist and professor at the Vanderbilt University School of Medicine, tells Yahoo Health. “But we’re not sure for how long this can happen.”

Zika is spreading rapidly throughout the Americas and the Caribbean and is expected to reach the United States by late spring or early summer. The World Health Organization recently predicted that the virus will spread to all but two countries in South America, Central America, and North America (including the U.S.), and officials in Brazil, Colombia, El Salvador, Ecuador, and Jamaica are urging women to hold off on having children.

Related: Zika Virus Transmitted in the U.S.

The CDC currently recommends that pregnant women avoid travel to areas of the world currently affected by Zika (the Americas and the Caribbean) and now is urging restricted sexual behaviors.

But the organization doesn’t specify how much time matters when it comes to a partner’s trip. “Recent visits are what are most important in terms of transmission risk,” board-certified infectious disease specialist Amesh A. Adalja, MD, an assistant professor at the University of Pittsburgh Medical Center, tells Yahoo Health.

If your partner visited a Zika-infected area two years ago, Schaffner says you should be fine. However, if it was three months ago, he urges caution: “People need to decide for themselves how risk-averse they are.”

However, Adalja says, scientists don’t really have a reliable time frame at this point: “An important scientific question to answer will be whether the virus has different kinetics in the male genital tract than in the blood — that will determine the ideal length of protection needed.”

Related: Is Zika Virus Contagious?

And, while it sounds extreme, that unknown factor is why the CDC is recommending pregnant women use protection for the duration of their pregnancy if their partner meets the specified criteria.

Scientists currently believe that Zika leaves the bloodstream within a week or so after symptoms begin. But viruses like Ebola have been found to stick around in semen for months after a patient no longer exhibits symptoms, which could be prompting the abundance of caution in terms of Zika.

“Public health agencies don’t want to make a recommendation and have to change it,” says Adalja. “All you can do is relax it when you get more information.”

(Worth noting: Public Health England, the U.K. version of the CDC, currently recommends that pregnant women use a condom with a partner for 28 days after he has returned from an active Zika transmission area and for six months after recovery if he has a confirmed Zika infection.)

As for the oral sex warning, Adalja says it’s due to the potential that he virus could be transmitted through oral lesions, similar to HIV.

Have a partner who recently traveled to Texas or Florida, where returning travelers from Zika-infected areas have had the disease? You don’t need to follow the precautions as of now. “There’s no evidence that this virus has reached those areas, so there’s no reason to depart from the CDC guidelines,” Adalja says.

While the sexual transmission warning is new, Adalja says the focus should still be on mosquitoes. “This shouldn’t distract people from the primary means of stopping Zika, which is to go after the mosquito,” he says. “Sexual transmission is a risk, but it’s not the main reason why it’s made its way around the globe.”

More on the Zika virus on Yahoo Health:

Is the Zika Virus Contagious?

Zika Virus Symptoms: What Are They?

Do Pregnant Women in the U.S. Need to Worry About Zika Virus?

What to Know About the Zika Virus If You’re Trying to Get Pregnant

U.S. Issues Treatment Guidelines for Infants Exposed to Zika

10 Essential Facts About the Zika Virus

What Happens When Countries Without Abortion Advise Against Pregnancy?

Can Brazil ‘Zika-Proof’ in Time for the Olympics?

Concern Over Zika Virus Grows

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