Zika virus mainly spreads through mosquito bites. The virus can pass from a pregnant woman to her unborn child. It can also spread from an infected person through sexual contact. There are reports of the virus spreading through blood transfusions.

Mosquito Bites 

Not all mosquitoes transmit Zika virus. Zika is primarily spread through the bite of an infected Aedes mosquito (Aedes aegypti and Aedes albopictus). These mosquitoes are found throughout Texas and can be active year-round in parts of Texas that experience mild winters. They typically lay eggs on the walls of water-filled containers like buckets, bowls, animal dishes, flowerpots, and vases. They can live indoors and outdoors and are most active between dawn and dusk. 

Infected people can transmit Zika virus to mosquitoes even if they’re not sick. If a mosquito bites an infected person, it can pass Zika virus to other people it bites after seven to 10 days. 

Although some cases of local transmission have been reported in Texas, most Texas cases of Zika are related to travel. These travel-related cases involve people who were bitten by an infected mosquito while traveling to an area where Zika is being spread and then diagnosed after returning home. 

Sexual Contact 

A person infected with Zika can pass the virus to his or her sex partner. Zika can be passed through any form of sexual contact, including vaginal, anal, and oral sex. Research shows Zika virus might stay in semen longer than in blood. Estimates indicate Zika virus may be transmissible in sexual fluids as long as 3 months. 

Mother to Unborn Child 

If infected with Zika while pregnant, a mother can also pass the virus to her unborn child. Zika infection during pregnancy can cause certain birth defects and developmental delays. If you are pregnant or planning to become pregnant, learn about prevention to avoid infection. 

Blood Transfusion 

To date, there have not been any confirmed blood transfusion transmission cases in the United States. Blood donations in the U.S. were screened for Zika virus from 2016-2021 but are no longer, as recommended by the U.S. Food and Drug Administration. Upon donation, blood donors may be asked by the blood donation center to answer questions regarding travel history and other questions related to possible recent Zika infection. 

More Transmission Information 

More information about Zika virus transmission is available on the U.S. Centers for Disease Control and Prevention (CDC) website.   

While many with Zika do not have any symptoms, the virus can cause fever, rash, joint pain, and conjunctivitis (red or pink eyes) lasting a few days to a week. Read more on the CDC’s Symptoms page. 

Once someone has been infected with Zika, it’s very likely they’ll be protected from future infections. There is no evidence that past Zika infection poses an increased risk of birth defects in future pregnancies. 

What health problems can result from getting Zika? 

Many people infected with Zika will have no symptoms or mild symptoms that last several days to a week. However, Zika infection during pregnancy can cause a serious birth defect called microcephaly and other severe birth defects.  Guillain-Barré syndrome, an uncommon sickness of the nervous system, is associated with Zika virus infection; however, only a small proportion of people with recent Zika virus infection get GBS.  

To diagnose Zika, your doctor will ask you about recent travel and symptoms you may have and may collect blood and urine to test for Zika or similar viruses.  

No. Currently, there is no vaccine or specific treatment for Zika virus.  

Visit your doctor if you have the symptoms listed above AND you live in or have visited areas affected by Zika, or have a sexual partner who lives in or has traveled to an affected area. 

If you are pregnant, regardless of symptoms, and you live in or have visited areas affected by Zika, or have a sexual partner who lives in or has traveled to an affected area, visit your doctor. 

• Your doctor may order blood and urine tests to look for Zika or other mosquito-borne diseases like dengue or chikungunya. Many people do not need testing for Zika based on current CDC recommendations.

If you think you have Zika, contact your doctor and take precautions to avoid mosquito bites in the week after becoming ill to prevent infecting others through local mosquito populations.  

• Wear Environmental Protection Agency (EPA)-registered insect repellents. When used as directed, these insect repellents—including those that contain DEET—are proven safe and effective even for pregnant and breastfeeding women. 
  • Mosquito Repellent Available as a Statewide Benefit – for Medicaid and other state programs  
• Cover up with long-sleeved shirts and long pants. 
• Keep mosquitoes out by keeping doors and windows closed and/or installing window screens. 
• Limit outdoor activities during peak mosquito times. Zika-carrying mosquitoes are most active between dawn and dusk. 
• Avoid travel to regions where Zika can be found. 

If you have been exposed to Zika and experience Zika symptoms, it's important to protect others from getting sick by avoiding mosquito bites the first week of illness.  

• At least weekly, empty, remove, or cover trash cans, buckets, old tires, pots, plant saucers, and other containers that hold water. 
• Keep gutters clear of debris and standing water. 
• Remove standing water around structures and from flat roofs. 
• Change water in pet dishes daily. 
• Rinse and scrub vases and other indoor water containers weekly. 
• Change water in wading pools and bird baths several times a week. 
• Maintain backyard pools or hot tubs. 
• Cover trash containers. 
• Water lawns and gardens carefully so water does not stand for several days. 
• Screen rain barrels and openings to water tanks or cisterns. 
• Treat front and back door areas of homes with residual insecticides if mosquitoes are abundant nearby. 
• If mosquito problems persist, consider pesticide applications around the home. 

Read the CDC's website on Controlling Mosquitoes at Home for more information.  

The most reliable way to avoid sexual transmission of Zika virus is to abstain from sex. You can reduce your risk of getting Zika through sex (including vaginal, anal, and oral sex) by using barrier contraceptive methods, such as condoms, consistently and correctly. Be especially cautious when you or your partner travels to or lives in an area where Zika is found . 

Follow the U.S. Centers for Disease Control and Prevention (CDC) guidance for prevention of sexual transmission. 

Zika virus is linked to birth defects and other developmental delays. One possible defect is microcephaly, a condition where a baby's head is much smaller than expected. The virus is also known to cause other poor birth outcomes in some women infected during their pregnancy, such as miscarriage and stillbirth. 

Discuss with your doctor any history of potential exposure to Zika and/or Zika-like illness that you or your sex partner may have had. 

Pregnant women living in Texas—particularly along the Texas-Mexico border—should be especially cautious to protect against mosquito bites and sexual transmission of Zika. 

The CDC recommends pregnant women not travel to areas with a Zika outbreak. Pregnant women and couples trying to become pregnant within the next 3 months and traveling to areas reporting past or current Zika transmission, but no current confirmed recent outbreak, should work with their healthcare providers to carefully consider the risks and possible consequences of travel to areas with risk of Zika. 

The CDC also recommends that all pregnant women who have a sex partner (male or female) who has traveled to or resides in an area with Zika use barrier contraceptive methods, such as condoms, every time they have sex, or they should not have sex during the pregnancy. 

Additional recommendations regarding Zika prevention for pregnant women can be found on the CDC website Clinical Considerations for Pregnant Women with Possible Zika Virus Infection. 

Outbreaks of Zika have occurred in many countries. Because the virus spreads from place to place through human travel, DSHS encourages people to follow the CDC's travel precautions for countries and regions where Zika virus transmission is ongoing. Pregnant women should not travel to areas affected by Zika. 

Most Texas cases of Zika are related to travel. These travel-related cases involve people who were infected while visiting areas where Zika is being spread and then diagnosed after returning home. 

DSHS recommends travelers prevent infection by 

• avoiding mosquito exposure, 
• taking precautions against sexual transmission, and 
• using screens or closing windows and doors. 

Travelers should avoid mosquito bites for 21 days following their return if asymptomatic or 7 days after the onset of illness, if ill. Travelers should also use EPA-registered insect repellents to prevent spreading the virus to mosquitoes in Texas. See the CDC’s Recommendations for Travelers and People Living Abroad for more information. 

Travelers should also take precautions against sexual transmission to their partners for 2 or 3 months after returning from travel, depending on the specific situation. See the CDC’s Sexual Transmission of Zika Virus page for more details. 

If I live in or am traveling to an area with risk of Zika, should I be concerned about Zika? 

People who live in or are traveling to areas where Zika is being spread should take steps to prevent mosquito bites and sexual transmission of Zika. 

Texans who live along the Texas-Mexico border—particularly those who are pregnant—should be especially cautious to prevent mosquito bites and protect themselves from sexual transmission of Zika virus. 

Should pregnant women travel to areas with risk of Zika? 

The CDC recommends pregnant women not travel to areas with a Zika outbreak. Pregnant women and couples trying to become pregnant within the next 3 months and traveling to areas reporting past or current Zika transmission, but no current confirmed recent outbreak, should work with their healthcare providers to carefully consider the risks and possible consequences of travel to areas with risk of Zika.  

If you work or spend a lot of time outdoors, there is a greater chance that you could be bitten by a mosquito that may carry Zika virus. 

When you’re outside, wear clothing that covers exposed skin. This can include hats with mosquito netting and socks to cover your ankles. In warmer weather, wear lightweight, loose-fitting pants and long-sleeved shirts. 

Improve your outdoor settings by removing standing water in bins, bottles, buckets, tires, and wheelbarrows. Cover trash cans or containers where water can collect. 

Local leaders can take action to help protect communities from Zika virus: 

• Provide monitoring and surveillance of mosquito activity. 
• Improve mosquito abatement efforts. 
• Develop a local plan for mosquito reduction and surveillance; plan for extra control measures, if needed. 
• Encourage people to report illegal dumpsites and standing water, and respond quickly to these complaints. 
• Clean up illegal dumpsites and collect heavy trash. 
• Keep public drains and ditches clear of weeds and trash so water will not collect. 
• Treat standing water with larvicide (such as mosquito "dunks") when the water will be present for more than seven days. 
• Conduct neighborhood outreach about what people can do to protect themselves and their families from mosquito bites. 

Vector control professionals can read the American Mosquito Control Association 's Mosquito Control recommendations for more information.  

The Texas Department of State Health Services (DSHS) updates its testing guidance based on local need and national scientific guidance. There is now increased scientific knowledge of the disease and the limitations of available tests. At this time, DSHS does not recommend testing for asymptomatic non-pregnant individuals. DSHS recommends testing only for specific groups of people, including: 

• Symptomatic pregnant women with possible Zika exposure, including travel to an area of Zika risk or sexual contact with a person with recent travel to an area of Zika risk 
• Symptomatic people (not pregnant) with travel to an area with an active Zika outbreak, as indicated by CDC Travel Health Notices, or history of Zika outbreaks. 

See your doctor if you have Zika symptoms and have recently been in an area with risk of Zika. Your doctor may order tests to look for Zika or similar viruses like dengue and chikungunya.  

There is no specific treatment or vaccine for Zika virus. However, if you feel sick and are concerned you may have been exposed to Zika, visit your doctor and treat your symptoms accordingly. To feel better, get plenty of rest and drink a lot of fluids. While you are sick, as well as after the virus has left your body, you should continue to follow Zika prevention precautions such as using EPA-approved insect repellent and taking steps to prevent sexual transmission of the virus.  

Currently, there is no evidence that a woman who has recovered from Zika virus infection (the virus has cleared her body) will have Zika-related pregnancy complications in the future. Based on information about similar infections, once a person has been infected with Zika virus and has cleared the virus from his or her body, he or she is likely to be protected from future Zika infections.  

If you are pregnant or planning on becoming pregnant, talk to your doctor about any possible exposure to Zika that you or your sex partner may have had. Pregnant women living in Texas—particularly along the Texas-Mexico border—should be especially cautious to protect against mosquito bites and sexual transmission of Zika.  

Although Zika virus has been detected in breast milk, there are no confirmed examples of transmission of Zika to babies tied to breastmilk from an infected mother. Current evidence suggests the benefits of breastfeeding outweigh the theoretical risks of Zika virus transmission.  

The mosquitoes that transmit Zika can be found throughout the state. Also, many Texans travel to places where Zika is being spread. This increases the risk of Texas mosquitoes picking up the virus and spreading it in Texas communities. 

Local mosquito-borne spread of Zika has been reported in the continental United States, including in places along the Texas-Mexico border. The Texas Department of State Health Services (DSHS) urges Texans who live along the Texas-Mexico border to remain on alert for Zika and to continue to take precautions against mosquito breeding and mosquito bites year-round.  

Texas has made significant progress in its efforts to minimize the impact of Zika on the state. While local transmission has occurred in Texas, public health officials do not expect widespread transmission across large geographic areas. Small pockets of cases in limited clusters continue to be possible. This assessment is based on the patterns with Zika and dengue, a similar virus spread by the same mosquitoes. 

The Texas Department of State Health Services (DSHS) is the lead state agency preparing for, coordinating, and responding to public health and medical incidents involving Zika virus. For emergency preparedness and response, DSHS operates within the overall context of emergency management in Texas, and in conjunction with local, state, and federal partners. Local health departments throughout Texas also play a key role in preparing for and responding to the impacts of Zika virus in their communities, including addressing local mosquito surveillance and control measures.