4 things pregnant women need to know about Zika virus

Zika virus - mosquito
The Zika virus is a mosquito-borne infection that usually causes very mild symptoms.

Updated April 14, 2016

“Have you heard about this Zika infection?” a patient asked me during her ultrasound. “What do you think?”

I have been following the news about Zika virus, specifically its link to microcephaly, which the Centers for Disease Control and Prevention (CDC) confirmed in April 2016. An increased number of babies in Brazil are being born with this congenital malformation, in which the baby’s head and brain are unusually small. There also have been reports of U.S. travelers, including a few in Texas, contracting the Zika virus while visiting affected countries.

The Centers for Disease Control and Prevention on Jan. 15 issued a warning advising pregnant women to postpone travel to areas affected by Zika virus, including Mexico, Puerto Rico, and parts of Central America and South America.

My patient had already canceled a planned Mexican vacation, but also was worried about an upcoming trip to Florida. I reassured her there is no need to avoid U.S. mainland destinations at this time. There are likely other pregnant women who have wondered about the Zika virus, so I’ve written this blog post to get them up to speed.

1. What is Zika virus and how is it contracted?

The Zika virus is a mosquito-borne infection that usually causes very mild symptoms. In fact, 80 percent of those infected never even know they have it. Common symptoms, which can last from a few days to a week, include a fever, rash, joint pain, headache, and conjunctivitis (red eyes).

The Aedes species mosquitoes that spread Zika virus are found throughout the world, including Texas. These mosquitoes (which are recognizable by the white markings on their legs) have also been known to carry West Nile disease, yellow fever, and dengue virus.

There is no medicine to treat Zika virus, nor is there a vaccine. Health care providers may recommend treating symptoms with rest, fluids, and medications such as acetaminophen to relieve fever and pain.

(UPDATED: Feb. 3, 2016)

Dallas County health officials on Feb. 2, 2016, reported a case of suspected sexual transmission of the Zika virus to a local resident from an “ill individual who returned from a county where Zika virus is present.” Specific details about the case are not available.

This is not the first report of possible sexual transmission of the Zika virus. Sexual transmission is thought to be responsible for an infection in a Colorado woman who contracted the virus after having vaginal sexual intercourse with her husband, who had returned from Senegal where he worked on a research project involving mosquitoes. The semen was not tested, and hematospermia (blood in the semen) may have contributed to the transmission. In Tahiti, Zika viral particles have been isolated in the semen of a man who experienced symptoms of Zika infection.

What does this report mean for women who are pregnant? For now, I suggest that you exercise caution. If your partner has recently returned from an area where Zika infections are present, use condoms consistently or abstain from sex for the remainder of the pregnancy. Condoms provide very good protection against the sexual transmission of viral illnesses. Check the CDC website for more recommendations concerning sexual transmission of the Zika virus.

2. Where is Zika virus found?

The Zika virus was first detected in animals in 1947 in Uganda, and spread to other parts of Africa and Asia. It then crossed the Pacific Ocean, and in March 2015, the first case was reported in Brazil. Infections have now been reported in multiple Latin American countries.

There have been no reported cases of people contracting the Zika virus through mosquitoes in the United States. However, some people have been diagnosed with Zika virus in the U.S., including a Texas woman who had recently returned from a trip to Central America. A woman in Hawaii, who lived in Brazil during the first part of her pregnancy, gave birth recently to a baby with microcephaly.

Even though there haven’t been any cases of people contracting the disease by mosquito in the United States, at least one type of mosquito that can transmit the virus is found here. Texas and Florida appear especially vulnerable to the spread of Zika infection, according to computer modeling that combined information about mosquitoes, temperature profiles, and historical data about flights to the United States from areas with known infections.

3. Does Zika virus cause birth defects?

(Updated: April 14, 2016)

In April 2016, the CDC confirmed that Zika virus can cause microcephaly. The organization also said the virus can cause other serious birth defects involving a baby’s brain. There is also concern that the Zika virus can infect the placenta and lead to poor growth of a baby.

Microcephaly can lead to a range of problems – from mild to severe to life-threatening – including seizures, developmental delay, intellectual disability, hearing loss, and vision problems. Microcephaly also can be caused by other viruses, such as rubella. Because most of the growth of a baby’s brain occurs in the third trimester, the condition may not be detected until a third-trimester ultrasound, if one is performed, or after birth.

In a few cases, amniocentesis – or taking fluid from around the baby – was used to confirm that the virus was present in the amniotic fluid surrounding the baby. The CDC also tested the brains of two babies with microcephaly who died shortly after birth and found that the Zika virus was present. While this still doesn’t prove that the Zika virus caused the abnormal brain development, it is concerning enough for us to recommend some precautions for pregnant women.

(UPDATED: Feb. 6, 2016)

The CDC’s recommendations regarding this disease may change frequently. And on Feb. 5, 2016, the CDC made another alteration in the indications for testing for Zika infection. They now suggest that all pregnant women who traveled to an area where there was active Zika infection be tested for evidence of infection between two and 12 weeks after returning.

This is a complicated recommendation. We will be offering testing to women for a disease for which there is no treatment. If you are in the later stages of pregnancy, ultrasound is the only meaningful testing we can offer – and of course we will (and which is what we would have done before this new change). I am also concerned about telling women they have likely been infected early in pregnancy, because we don’t have any knowledge of when the fetus is most likely to be harmed by this virus.

For now, if you are pregnant, expect to be asked about your travel history and offered screening. If you have any questions, ask your doctor – or direct them to us at yourpregnancymatters@utsouthwesten.edu.

4. How can pregnant women protect themselves?

For now, it’s best to heed the CDC’s travel warnings. The recommendations are changing as new information comes in, so look for the up-to-date list of countries on the CDC’s Zika travel health notices page. If travel can’t be avoided, protect yourself from mosquito bites.

A good insect repellant is a must – especially if you’re in Texas or Florida. Mosquitoes can be thick during the summer, and while Zika virus has not been detected here yet, we do see cases of West Nile virus and other mosquito-borne infections. DEET is one of the most effective mosquito repellants, and while it has a reputation of being a potent chemical, using it as directed on your skin will not harm you or your baby during pregnancy.

Some women prefer natural repellants such as pyrethrin. You should not apply this to your skin, but you can use it on your clothing before you get dressed to repel mosquitoes. The Environmental Protection Agency offers tips to help you select an appropriate insect repellent.

A few other precautions you can take to protect yourself from mosquito-borne infections:

  • Wear long-sleeve shirts and long pants if the weather permits. Avoid mosquito-repellant wristbands and clip-ons as they have been shown to have minimal to no effectiveness.
  • Protect your home. Use window or door screens to keep mosquitoes out of your home. Sleep under a mosquito net if you are unable to keep mosquitoes out of your home.
  • Use mosquito abatement programs in your yard. Empty standing water from containers such as buckets or flowerpots to keep mosquitoes from finding a place to breed. If you can’t get rid of all standing water, use larvicides, products that can be sprayed or that float in water and kill mosquito larvae.
  • Be aware of spraying plans in your community. Mosquitoes become infected after biting infected people, so spraying is an effective way to slow mosquito-borne diseases. I expect this will be used more heavily this summer – especially if the link to congenital abnormalities is strengthened.

Also in response to the Zika, national organizations such as the National Marrow Donor Program and the American Red Cross have instituted additional screening guidelines for the virus for blood and cord blood donations.

If you have questions about an upcoming trip or have taken a recent trip to an affected country, talk to your physician about the possible risks.

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