Zika Virus Information

The Zika virus (Zika) is spread to people primarily through the bite of an infected Aedes aegypti or Aedes albopictus species of mosquito. Mosquito transmission of the Zika virus is found in nearly 50 countries in Central and South America, the Caribbean, Pacific Islands and Africa.

Most people with Zika will not have symptoms. Once a person is infected, he or she is likely to be protected from future infections.  However, they can pass the virus on to others if bitten by the Aedes mosquito while the virus is present in their blood or, if a man is infected, through sexual contact. This infectious period usually lasts seven days. The most common symptoms of Zika are fever, rash, joint pain, and conjunctivitis (red eyes). If a person does get sick, the illness is usually mild with symptoms lasting for several days to a week after being bitten. People usually don’t get sick enough to go to the hospital, and they very rarely die of Zika. For this reason, many people might not realize they have been infected. However, Zika virus during pregnancy can cause serious birth defects, including microcephaly and other severe fetal brain defects. There are no vaccines to prevent Zika virus disease and no drugs to treat it.

Travel Information

Zika virus is currently transmitting in countries and terrorities including Mexico, the U.S. Virgin Islands, Puerto Rico, Brazil, Costa Rica, Panama, Peru, Jamaica and others. See a complete listing of countries.

If traveling to a country with active Zika transmission you should take steps to protect yourself while traveling. In addition, you should take steps to prevent mosquito bites when you return to the States.

Protect Yourself, Family and Friends When Traveling

  • Before traveling, check to see if your destination is impacted by local Zika transmission. See a complete listing of countries.
  • Pack to prevent Zika virus.
    • Pack EPA-registered insect repellant, reapply often as directed and remember when using sunscreen to apply insect repellant after sunscreen.
    • Pack long-sleeved shirts and pants and wear them as often as possible. Cover as much exposed skin as possible.
    • Pack a mosquito bed net if mosquitoes can get to where you are sleeping.
      • Choose a World Health Organization approved bed net, white, compact, rectangular with 156 holes per square inch, long enough to tuck under the mattress.
      • Permethrin treated bed nets provide more protection than untreated nets.
    • Pack condoms, Zika virus can be sexually transmitted.
  • Choose a hotel or lodging with air conditioning, or screens on windows and doors.
    • If your hotel or lodging does not have these items, mosquito bed netting is critical.
  • Follow all steps to protect yourself, friends and family from mosquito bites.

Protect Yourself, Family, and Friends When You Return—Stop the Spread of Zika

  • Watch for Zika virus symptoms after you return home.
  • Use an EPA-registered insect repellant for three weeks upon your return and take measures to prevent yourself from mosquito bites.
  • Use condoms when you have sex.
  • Call your doctor immediately if you suspect you may have Zika virus.

Infection Prevention

Everyone can help prevent Zika transmission from occurring in Missouri by implementing two simple steps—control mosquitoes inside and outside your home and use personal protective measures to prevent mosquito bites and prevent sexual transmission.

Preventing Mosquito Bites

Zika is primarily spread through the bite of an infected mosquito. Zika can also be sexually transmitted and can be passed from a pregnant mother to her fetus during pregnancy. Because biting mosquitoes are the primary means of transmission it is very important to prevent mosquito bites.

Protect Yourself, Family, Friends and Neighbors from Mosquito Bites

  • Wear insect repellant on exposed skin and your clothing.
    • Use Environmental Protection Agency (EPA) registered insect repellants with one of the following active ingredients:  DEET, picaridin, IR3535, oil of lemon eucalyptus, or para-menthane-diol.  EPA-registered insect repellants have proven safe and effective even for pregnant and breast-feeding women.
      • Always follow the product label instructions.
      • Reapply insect repellant as directed.
      • Do not spray repellant on the skin under clothing.
      • When using sunscreen, apply the sunscreen before applying insect repellant.
      • The effectiveness of natural insect repellants (non-EPA registered) is unknown against diseases like Zika.
  • To protect your child from mosquito bites:
    • Do not use insect repellant on babies younger than 2 months old.
    • Do not use products containing oil of lemon eucalyptus or para-menthane-diol on children younger than 3 years old.
    • Dress your child in clothing that covers arms and legs.
    • While outside, cover crib, stroller and baby carrier with mosquito netting.
    • Do not apply insect repellant onto a child’s hands, eyes, mouth or cut or irritated skin.
    • Adults: Spray insect repellant onto your hands then apply to a child’s face.
  • Wear long-sleeved, loose fitting, light colored shirts and pants when possible.
  • Treat clothing and gear with permethrin or purchase permethrin-treated items.
    • Treated clothing remains protective after multiple washings. See product information to learn how long protection will last.
    • If treating items yourself, follow product instructions carefully.
    • DO NOT use permethrin products directly on the skin.
  • Stay in places with air conditioning and window and door screens to keep mosquitoes outside.
  • When staying outdoors sleep under a mosquito net if you are not able to protect yourself from mosquito bites.
  • Take steps to control mosquitoes inside and outside your home.

Preventing Sexual Transmission

A man with Zika virus can pass it to his female or male sex partners. Zika can be passed before symptoms start, while he has symptoms, and after his symptoms end. Scientists do know the Zika virus remains present in semen longer than the virus circulates in the blood of infected individuals. Those living in or traveling to areas where Zika is circulating should take extra precautions to prevent the sexual transmission of Zika. The timeframe for using condoms or waiting to have sex will vary based on the couple’s situation and concerns. Not having sex can eliminate your risk of getting Zika from sex.

Protect your Partner from Zika

  • If traveling to or living in areas where Zika is being actively transmitted, use condoms from start to finish every time you have sex.
    • Men who traveled to an area with active Zika transmission but did not develop symptoms should use condoms for at least 8 weeks after leaving that area.
  • Because Zika can cause certain birth defects, take steps to prevent your partner from getting Zika during pregnancy or from becoming pregnant.
  • If you suspect you have or had Zika tell your doctor or healthcare provider.
    • Share what steps you have or haven’t taken to prevent mosquito bites.
    • Share if you have had unprotected sex.

If you have been diagnosed with Zika virus, CDC recomends condoms should be used for at least six months after you have recovered to prevent the spread of Zika.

Couples Who Are Pregnant

  • Pregnant couples with male partners who live in or travel to areas with Zika should take steps to protect their pregnancy. Because Zika can cause birth defects, these couples should:
    • Use a condom every time they have sex or do not have sex during the pregnancy.
    • To be effective, condoms must be used correctly from start to finish, every time you have vaginal, anal, and oral (mouth-to-penis) sex.
    • A man who has Zika can pass it to his pregnant partner during sex, even if he does not have symptoms at the time or his symptoms have gone away.

Couples Trying to Become Pregnant

  • Men or women who live in or travel to an area with Zika who are concerned about trying to get pregnant should talk to their healthcare provider.
  • For women and men who have been diagnosed with Zika virus disease or who have symptoms of Zika after possible exposure to Zika virus, CDC recommends that healthcare providers
    • Advise women to wait at least 8 weeks after their symptoms first appeared before trying to get pregnant.
    • Advise men to wait at least 6 months after their symptoms first appeared before trying to get their partner pregnant.
    • Men should correctly and consistently use condoms for vaginal, anal, and oral (mouth-to-penis) sex or not have sex during this time period if they are concerned about the possibility of transmitting Zika virus to their sex partners.
  • For men and women without symptoms of Zika virus but who had possible exposure to Zika from recent travel or sexual contact, healthcare providers should recommend their patients wait at least 8 weeks after their possible exposure before trying to get pregnant.
  • Men and women without symptoms of Zika virus who live in an area with active Zika transmission should talk with their healthcare providers about their pregnancy plans during a Zika virus outbreak, the potential risks of Zika, and how they can prevent Zika virus infection during pregnancy.

Others Concerned About the Sexual Transmission of Zika

  • Anyone concerned about the sexual transmission of Zika and not concerned about pregnancy can consider using a condom every time they have vaginal, anal, and oral (mouth-to-penis) sex or not have sex. To be effective, condoms must be used correctly from start to finish, every time during sex.
  • For couples with a male partner who has traveled to an area with Zika, CDC recommends:
    • If the male partner has been diagnosed with Zika or has (or had) symptoms, the couple should consider using condoms or not having sex for at least 6 months after symptoms begin.
    • If the male partner does not develop symptoms, the couple should consider using condoms or not having sex for at least 8 weeks after the man returns.
  • For couples with a male partner living in an area with Zika, CDC recommends:
    • If the male partner has been diagnosed with Zika or has (or had) symptoms, the couple should consider using condoms or not having sex for at least 6 months after symptoms begin.
    • If the male partner has never developed symptoms, the couple should consider using condoms or not having sex while there is Zika in the area.
  • For couples with a non-pregnant female partner who lives in or has traveled to an area with Zika
      • It is not known if a woman can pass Zika to her sex partners.
      • Couples should also consider using condoms or not having sex.

If you suspect you have or had Zika tell your doctor or healthcare provider.

    • Share what steps you have or haven’t taken to prevent mosquito bites.
    • Share if you have had unprotected sex.

Mosquito Control

One of the most effective ways of preventing the spread of Zika virus is controlling the mosquito population by eliminating standing water in and around the home. Implementing the steps below can greatly reduce your risk of mosquito bites.

Control Mosquitoes Outside the Home

  • Tip n’ Toss – once a week empty and scrub, turnover, cover, or throw out any items that hold water like tires, buckets, planters, toys, pools, birdbaths, flowerpot saucers, or trash containers. Mosquitoes lay eggs near water.
    • Tightly cover water storage containers (buckets, cisterns, rain barrels) so that mosquitoes cannot get inside to lay eggs.
    • For containers without lids, use wire mesh with holes small enough to keep mosquitoes out..
    • Use larvicides to treat large containers of water that will not be used for drinking and cannot be covered or dumped out.  When using larvicides always follow label directions.
  • Use an outdoor flying insect spray where mosquitoes rest. Mosquitoes rest in dark, humid areas like under patio furniture, or under the carport or garage. When using insecticides, always follow label instructions.
  • If you have a septic tank, repair cracks or gaps. Cover open vent or plumbing pipes. Use wire mesh with holes smaller than an adult mosquito.

Control Mosquitoes Inside the Home

  • Keep windows and doors shut and use air conditioning when possible.
    • If keeping windows and doors open, install or repair broken screens. Do not leave doors propped open. This will prevent mosquitoes from coming into your house.
  • Keep mosquitoes from laying eggs inside your home. Once a week, empty, scrub, turnover, cover or throw out any items that hold water like vases and flowerpot saucers.
  • Kill mosquitoes inside your home.  Use an indoor flying insect fogger or indoor insect spray to kill mosquitoes and treat areas where they rest. These products work immediately, but may need to be reapplied. Always follow label directions.
    • Mosquitoes rest in dark, humid places like under the sink, in closets, under furniture, or in the laundry room.

More Information

The Centers For Disease Control Zika Page

Missouri Department of Health and Senior Services Zika Page

US State Department Zika Traveler Information