About the Zika Virus

What is the Zika virus?

Zika virus is spread to people through mosquito bites. The most common symptoms of Zika virus disease are fever, rash, joint pain, and conjunctivitis (red eyes). The illness is usually mild with symptoms lasting from several days to a week. Severe disease requiring hospitalization is uncommon.

What areas are currently affected?

In May 2015, the Pan American Health Organization (PAHO) issued an alert regarding the first confirmed Zika virus in Brazil. In the continental United States (with the exception of South Florida) no locally transmitted Zika cases have been reported. However, cases are occurring among persons who have traveled to affected areas of the world. Locally transmitted Zika virus has been reported in the Commonwealth of Puerto Rico, the U.S. Virgin Islands, and America Samoa.

For more information on affected areas: http://www.cdc.gov/zika/geo/index.html

What are the symptoms of Zika virus?

About 1 in 5 people infected with Zika virus become ill (i.e. develop Zika). The most common symptoms of Zika are fever, rash, joint pain, or conjunctivitis (red eyes). Other common symptoms include muscle pain and headache. The incubation period (the time from exposure to symptoms) for Zika virus disease is currently not known, but it likely to be a few days to a week.

The illness is usually mild with symptoms lasting for several days to a week. People usually don’t get sick enough to go to the hospital, and they very rarely die of Zika. Zika virus usually remains in the blood of an infected person for about a week, but if can be found longer in some people.

How is the Zika virus transmitted?

Through mosquito bites

Zika virus is transmitted to people primarily through the bite of an infected Aedes species mosquito (A. aegypti and A. albopictus). These are the same mosquitoes that spread dengue and chikungunya viruses. These mosquitoes typically lay eggs in and near standing water in things like buckets, bowls, animal dishes, flower pots and vases. They prefer to bite people and live indoors and outdoors near people. They are aggressive daytime biters, but they can also bite at night. Mosquitoes become infected when they feed on a person already infected with the virus. Infected mosquitoes can then spread the virus to other people through bites.

For more information on dengue and chikungunya viruses:

From mother to child

A pregnant woman can pass Zika virus to her fetus during pregnancy. Zika is a cause of microcephaly and other severe fetal brain defects. The full range of other potential health problems the virus may cause during pregnancy is being studied. A pregnant woman already infected with Zika near the time of delivery can pass the virus to her newborn around the time of birth.To date, there are no reports of infants getting Zika virus through breastfeeding.

For more information on Zika and pregnant women: http://www.cdc.gov/zika/pregnancy/index.html

Through sexual contact

Zika virus can be spread by a man to his sex partners as the virus is present in semen longer than in blood. All couples where one has recently returned from a high-risk area are strongly recommended to use condoms.

Through Blood Transfusion

There are currently no confirmed blood transfusion transmission cases in the United States, however there have been multiple reports in Brazil which are currently being investigated.

How is the Zika virus treated?

See your healthcare provider if you develop the symptoms described above and have visited an area where Zika is found. If you have recently traveled, tell your healthcare provider when and where you traveled. They may order specialized blood tests to look for Zika or other similar viruses like dengue or chikungunya.

There is no vaccine to prevent or specific medicine to treat Zika infections.

  • Get plenty of rest.
  • Drink fluids to prevent dehydration.
  • Take medicine such as acetaminophen (Tylenol®) to relieve fever and pain.
  • Do not take aspirin and other non-steroidal anti-inflammatory drugs.
  • If you are taking medicine for another medical condition, talk to your healthcare provider before taking additional medication.

If you are infected with Zika, prevent mosquito bites for the first week of your illness. During the first week of infection, Zika virus can be found in the blood and passed from an infected person to a mosquito through mosquito bites. An infected mosquito can then spread the virus to other people.

How can I prevent Zika virus?

No vaccine exists to prevent Zika virus disease.

Prevent Zika by avoiding mosquito bites using these tips:

  • Wear long-sleeved shirts and long pants
  • Stay in places with air conditioning or that use window and door screens to keep mosquitoes outside
  • Sleep under a mosquito bed net if you are overseas or outside and are not able to protect yourself from mosquito bites.
  • Use Environmental Protection Agency (EPA)-registered insect repellents. When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breast-feeding women.
  • Treat clothing and gear with permethrin or purchase permethrin-treated items
  • Mosquito Bite Prevention for Travelers

Prevention of sexual transmission for couples in which a man has traveled to or resides in an area with active Zika virus transmission

Couples in which a woman is pregnant

  • Couples in which a woman is pregnant should use condoms consistently and correctly or abstain from sex for the duration of the pregnancy.

Other couples concerned about sexual transmission

  • Couples in which a man had confirmed Zika virus infection or clinical illness consistent with Zika virus disease should consider using condoms or abstaining from sex for at least 6 months after onset of illness.
  • Couples in which a man traveled to an area with active Zika virus transmission but did not develop symptoms of Zika virus disease should consider using condoms or abstaining from sex for at least 8 weeks after departure from the area.

Additional Resources

For the most up to date travel notices related to Zika virus visit http://wwwnc.cdc.gov/travel/notices

Zika Breakthrough : Scientists detail how virus can attack fetal brain