Zika in the United States

Zika in the United States: What you need to know

The pesky Zika-carrying mosquitoes are transmitting the virus in the U.S.; here’s what you should know
August 16, 2016

It’s official: Zika has made its way to the United States, and it’s only a matter of time before it infiltrates additional communities across the mainland. A number of people in Florida were found to have been infected with Zika virus after being bitten by local mosquitoes, prompting the Centers for Disease Control and Prevention (CDC) to issue an unprecedented warning, advising against travel to the Miami neighborhood where Zika is actively circulating. We sat down with Texas A&M experts to find out more about the implications of Zika in the United States.

Q:  Where is Zika in the United States?

A:  We are already seeing transmission of Zika within U.S. territories like Puerto Rico and American Samoa, and a few cases in Miami, Florida. Still, due to factors like the widespread use of window screens and air conditioning, and other mosquito control measures, the disease is unlikely to have as large an impact and spread as quickly here as it has in some other parts of the world.

Q:  Will we see Zika in Texas?

A:  Like Florida, Texas is likely to be affected by Zika due to the warm climate and because Texas is home to the Aedes aegypti and Aedes albopictus mosquitoes that transmit the virus.

regions of U.S. affected by zika

Q: Who is at risk?

A: Anyone that hasn’t yet had the virus is potentially at risk, but the greatest public health threat is to pregnant women and their unborn children, due to the link to miscarriages and microcephaly, a birth defect in which infants are born with unusually small heads and often have corresponding brain damage.

who's at risk for zika

Q: How do I know if I’ve contracted the virus?

A:  Between 75 and 80 percent of those infected will not have any symptoms at all. For the other 20 to 25 percent, common symptoms of Zika include fever, skin rash, red eyes and joint pain. Some patients report muscle pain, general malaise, headache and vomiting. Symptoms, which start between two and seven days after exposure, typically last between two and seven days.

For pregnant women who have traveled to an area where Zika virus is transmitting between mosquitoes and humans, tests are available to determine whether or not they have Zika virus infection or if they have had Zika in the recent past. You will need to contact your physician for proper counseling and timing of such tests.

Zika symptoms

Q:  Is it safe to go outside? How can I protect myself from mosquito bites?

A:  There is no vaccine for the virus yet, so all preventive measures should be focused on two things: preventing mosquito bites and avoiding sexual transmission. This means eliminating standing water and other mosquito breeding sites, as well as having mosquito screens in all windows and using appropriate insect repellents when outdoors. Those returning from areas with Zika transmission or who otherwise think they could be infected should use condoms to avoid infecting their sexual partners. The CDC advises men who have been diagnosed with Zika use condoms or avoid sex for six months after onset of symptoms.

Q:  What ingredients should my repellent include?

A:  To combat the mosquitoes that transmit Zika virus, look for repellents with either 25 percent DEET or 20 percent Picardin. Still, don’t go above 50 percent DEET; it won’t give you any additional mosquito protection, and you may be more likely to have unwanted side effects. You can also consider wearing clothing that has been treated with permethrin.

Products that use “natural” ingredients—such as soybean oil, geraniol or citronella—haven’t been shown to be effective.

Q:  How can I keep mosquitoes away from my home?

A:  The EPA recommends these preventive measures that may keep mosquitoes from breeding around your home:

Remove Mosquito Habitats
  • Eliminate standing water in rain gutters, old tires, buckets, plastic covers, toys or any other container where mosquitoes can breed. Remember that a container as small as a bottle cap may have enough water to harbor mosquito larvae.
  • Empty and change the water in bird baths, fountains, wading pools, rain barrels and potted plant trays at least once a week to destroy potential mosquito habitats.
  • Drain or fill temporary pools of water with dirt.
  • Keep swimming pool water treated and circulating.
Use Structural Barriers
  • Cover all gaps in walls, doors and windows to prevent mosquitoes from entering.
  • Make sure window and door screens are in good working order.
  • Completely cover baby carriers and beds with netting.
Avoid Getting Bitten
  • Wear insect repellents with either 25 percent DEET or 20 percent Picardin.
  • Keep mosquitoes away from exposed skin by wearing long-sleeved shirts, long pants and socks.
  • Tuck shirts into pants and pants into socks to cover gaps in your clothing where mosquitoes can get to your skin.
  • Stay indoors at sunrise, sunset and early in the evening when mosquitoes are most active.
Q:  I’m pregnant. Are insect repellants safe to use?

A:  The CDC states insect repellants registered by the Environmental Protection Agency (EPA) are proven to be safe and effective for pregnant and breastfeeding women. You can use their online search tool to find a repellant that’s right for you, keeping in mind the product you choose should contain 25 percent DEET or 20 percent Picardin.

Q:  Should pregnant women avoid travel to certain states?

A:  A travel advisory has been issued by the CDC warning pregnant women not to travel to certain areas of Miami, Florida, an area with active Zika transmission. CDC Director Tom Frieden also advised women who have traveled to the Miami area within the last month to postpone trying to get pregnant for at least eight weeks; in an effort to reduce the chance of having a baby born with Zika-related birth defects. 

Q:  If I had, or was exposed to, Zika, when it is safe to conceive?

A:  Both women who are diagnosed with Zika virus disease and asymptomatic women with possible exposure to Zika virus should wait at least eight weeks from symptom onset or exposure to attempt pregnancy, and their male partners diagnosed with Zika virus disease should wait at least six months from symptom onset to attempt pregnancy. Men who have possible Zika virus exposure without clinical illness consistent with Zika virus disease should wait at least eight weeks after possible exposure before attempting pregnancy.

Q:  Will Zika affect future pregnancies?

A:  No. The main risk to the baby is when the infection occurs during the pregnancy. Once a person has been infected, he or she is likely to be protected from future infections, although this is based on limited data and has not been confirmed.

For more basic information on the virus, modes of transmission and symptoms, visit our explainer:  What you should know about Zika virus.

— Holly Shive

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