What is Zika?

Zika is disease caused by a virus that is primarily spread to people through the bite of an infected mosquito. Many people who get infected never have symptoms. In people who get sick, symptoms (fever with rash, joint pain, or red eyes) are usually mild and resolve completely.

Zika can cause serious birth defects in babies born to women who were infected with Zika virus during pregnancy.  Current CDC research suggests that Zika also is strongly associated with Guillain-Barré syndrome (GBS), a rare disorder that can cause muscle weakness and paralysis for a few weeks to several months. Only a small proportion of people with recent Zika virus infection get GBS. Most people fully recover from GBS, but some have permanent damage. For more information, see Zika Health Effects and Risks.

Zika can also spread through sex. People with Zika can pass Zika through sex to their partners even if they do not have symptoms at the time, or if their symptoms have gone away. We do not know how long a person who has had Zika can pass it on through sex.

The mosquitoes that spread Zika usually do not live at elevations above 6,500 feet (2,000 meters). People who live in areas above this elevation are at a very low risk of getting Zika from a mosquito unless they visit or travel through areas of lower elevation. Because there is no vaccine or treatment for Zika, people living in areas with Zika should take steps to prevent infection.

Prevent Mosquito Bites

All residents living in areas with Zika should take steps to prevent mosquito bites:

• Cover exposed skin by wearing long-sleeved shirts and long pants.
• Use insect repellents that are registered with the Environmental Protection Agency (EPA) and contain DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol, or 2-undecanone (methyl nonyl ketone). Always use as directed.
  • Pregnant and breastfeeding women can use all EPA-registered insect repellents, including DEET, according to the product label.
  • Most repellents, including DEET, can be used on children older than 2 months of age (OLE and PMD should not be used on children younger than 3 years). Adults should spray insect repellent onto their hands and then apply to a child’s face.
• Use permethrin-treated clothing and gear (boots, pants, socks, tents).* You can buy pre-treated items or treat them yourself.
• Stay and sleep in screened-in or air-conditioned rooms.
• Sleep under a mosquito bed net if air conditioned or screened rooms are not available or if sleeping outdoors.
• Mosquito netting can be used to cover babies younger than 2 months old in carriers, strollers, or cribs to protect them from mosquito bites.

*Permethrin should not be used in Puerto Rico.

Pregnant Women and Zika

Zika virus can pass from a pregnant woman to her fetus and can cause a serious birth defect of the brain called microcephaly in babies of women who had Zika virus while pregnant. Babies with microcephaly often have smaller brains that might not have developed properly. Other problems, such as eye defects, hearing loss, and impaired growth, have been detected among fetuses and infants infected with Zika virus before birth.

Pregnant women should not travel to any area with Zika outbreaks (red areas). If travel to one of these areas is necessary, pregnant women should talk to their doctor or other health care provider first, strictly follow steps to prevent mosquito bites, and practice safe sex during the trip.

Before traveling to other areas with risk of Zika (purple areas), pregnant women should discuss their travel plans with their health care provider and carefully consider the risks and possible consequences of travel to these areas.

For more information about pregnancy and Zika, visit http://www.cdc.gov/zika/pregnancy/.

Practice Safe Sex for Zika Prevention

Condoms (or other barriers to prevent infection) can reduce the chance of getting Zika from sex. To be effective, condoms must be used correctly from start to finish, every time during vaginal, anal, and oral sex. People with Zika can pass Zika to their partners even if they do not have symptoms at the time, or if their symptoms have gone away. Not having sex can eliminate the risk of getting Zika from sex.

• People with pregnant partners should use condoms every time they have sex or should not have sex during the pregnancy.
• All pregnant women with sex partners who live in or have traveled to an area with Zika should use condoms or not have sex during their pregnancy, even if their partners do not have Zika symptoms, or if their symptoms have gone away.
• All people who live in or have traveled to an area with Zika should consider using condoms to protect their sex partners.

For more information about Zika and sexual transmission, visit http://www.cdc.gov/zika/transmission/sexual-transmission.html.

Zika Testing for Pregnant Women

Please visit CDC’s Zika health care provider website for testing recommendations for pregnant women.

Discuss Pregnancy Planning with Healthcare Provider

If you are thinking about pregnancy, talk with your healthcare provider and wait to become pregnant (see “Women Trying to Become Pregnant” for how long to wait). You also should use condoms after travel to protect your sex partners from Zika even if you are not pregnant or trying to become pregnant.

Women who are at risk of Zika and do not want to get pregnant should talk with their doctor or other healthcare provider about ways to prevent unintended pregnancy, including birth control methods. Women should consider safety, effectiveness, availability, and acceptability when choosing a birth control method. 

If You or Your Partner Becomes Pregnant, Talk to Your Doctor

• You are at risk of getting Zika throughout your pregnancy. For this reason, CDC recommends testing at the first prenatal visit and a second test in the second trimester.
• If you have symptoms of Zika (fever, rash, joint pain, or red eyes) at any time during your pregnancy, you should be tested for Zika. A healthcare provider may also test for similar diseases, like dengue or chikungunya.
• CDC has guidance to help doctors decide what tests are needed for pregnant women who may have been exposed to Zika.

More Information

• Zika Virus
• Zika Travel Information
• Zika and Sexual Transmission
• Women and Their Partners Who Are Thinking about Pregnancy
• Zika and Pregnancy