Zika and Sexual Transmission

Interim Guidelines for Prevention of Sexual Transmission of Zika Virus — United States, 2016

What we know

Zika virus can be spread by a man to his sex partners.
In known cases of likely sexual transmission, the men had Zika symptoms. But the virus can be spread before, during, and after men have symptoms.
The virus can be present in semen longer than in blood.

Infographic: Pregnant and living in an area with Zika?

Pregnant and living in an area with Zika? [PDF - 2 pages]

What we do not know

We do not know how long the virus is present in semen in men who have had Zika.
We do not know if infected men who never develop symptoms can have Zika virus in their semen.
We do not know if infected men who never develop symptoms can transmit Zika virus through sex.
We do not know if a woman can transmit Zika virus to her sex partners.
We do not know if Zika can be spread through oral sex.
- Although there are no known cases of Zika transmission from mouth-to-penis oral sex, Zika is known to be spread from semen.
- It is not known if Zika can be spread from other body fluids that may be exchanged during oral sex, including saliva and vaginal fluids.

Pregnant? What you should know about Zika and sex

Zika virus can be spread by a man to his sex partners. Because of the link between Zika and birth defects, take steps to prevent infection during your pregnancy. Talk to your doctor about the steps you can take.

If you have a male partner who lives in or has traveled to an area with Zika, protect your pregnancy.

If you have vaginal, anal, or oral (mouth-to-penis) sex, use a condom the right way, every time, (warning: this link contains sexually graphic images) during your pregnancy.

Infographic thumbnail: Pregnant? Read this before you travel.

Pregnant? Read this before you travel[PDF - 2 pages]

Don’t have sex with your male partner during your pregnancy. Not having sex is the best way to be sure that someone does not get sexually transmitted Zika virus.

Your male partner should also take steps to prevent mosquito bites to prevent further spread of the virus.

If you think your male partner may have or had Zika, tell your healthcare provider about

His travel history
How long he stayed
If he took steps to prevent mosquito bites
If you had sex without a condom

Women: Trying to get pregnant?

At this time, we don’t know how long Zika is present in semen in men who have had Zika, and we don’t know if men who had Zika but never developed symptoms can have Zika in their semen. If you have a male sex partner who lives in or has traveled to an area with Zika and are concerned about trying to get pregnant, talk to your healthcare provider about

His travel history
How long he stayed
If he took steps to prevent mosquito bites
If you had sex without a condom

Men: Do you have a pregnant partner?

Zika virus can be spread by a man to his sex partners. Because of the link between Zika and birth defects, take steps to prevent your partner from getting Zika during her pregnancy. Talk to your doctor about what steps you can take.

If you live in or travel to an area with Zika, protect your partner’s pregnancy.

If you have vaginal, anal, or oral (mouth-to-penis) sex, use a condom the right way, every time, (warning: this link contains sexually graphic images) during the pregnancy.

Don’t have sex with your pregnant partner during the pregnancy. Not having sex is the best way to be sure that someone does not get sexually transmitted Zika virus.
You should also take steps to prevent mosquito bites to prevent further spread of the virus.

If you think you may have or had Zika, tell your healthcare provider about

Your travel history
How long you stayed
If you took steps to prevent mosquito bites
If you had sex with your pregnant partner without a condom

Are you concerned about getting Zika from a sex partner?

At this time, there is no evidence that women can transmit Zika virus to their sex partners.
Only people whose male sex partners have traveled to or live in an area with Zika transmission need to be concerned about getting Zika from sex. Based on what we know today, traveling to or living in areas without Zika transmission does not pose a risk of getting infected with Zika.
If you are concerned for any reason, you can use a condom the right way, every time, you have sex (warning: this link contains sexually graphic images). This includes vaginal, anal, and oral sex Condoms also prevent HIV and other STDs. Not having sex is the best way to be sure that you do not get sexually transmitted Zika virus.

Testing

There are tests to detect Zika virus in semen but they are not widely available. We have a limited understanding of how to interpret the results of such tests, so testing of semen is not recommended. As we learn more, these tests may become more helpful to determine the risk of sexual transmission of Zika.