Zika Virus Disease

Zika is a virus that spreads to people primarily through bites of infected mosquitoes. Most people exposed to Zika virus will have no symptoms or only mild symptoms. The main concern about this virus is that it can pass from a mother to her baby during pregnancy and have serious results, including birth defects. People exposed to Zika virus who have no symptoms are said to have Zika virus infection; those who have symptoms are said to have Zika virus disease. Both conditions will be referred to as “Zika” below.

Zika virus is usually spread between people through the bite of an infected mosquito. The primary mosquito that spreads Zika virus is the yellow fever mosquito (Aedes aegypti); the Asian tiger mosquito (Aedes albopictus) can also spread the virus. An infected person will have the virus in the blood, especially in the first week of illness. If a mosquito bites an infected person while the virus is still in the person's blood, the mosquito becomes infected. If the infected mosquito lives long enough for the virus to multiply, the mosquito can then bite another person to pass on the virus. People who are infected but who are not sick can still pass the virus on to mosquitoes that bite them. Zika virus can also spread from a mother to her baby during pregnancy or around the time of birth. Zika virus can spread through unprotected sex, such as not using condoms during sex, from a person who has Zika to his or her sex partners, even if the infected person is not sick. The virus can also be spread through blood transfusion.

Who gets Zika?
Anyone who lives in or travels to an area with risk of Zika, and has not already been infected, can get Zika. Anyone who has unprotected sex with someone who lives in or travels to these places can also become infected. For a map of areas with risk of Zika, see CDC's Zika webpage: http://www.cdc.gov/zika/geo/index.html.

What are the symptoms of Zika?
About 80% of people who are infected with Zika virus do not become sick. For the 20% who do become sick, the most common symptoms include fever, rash, joint pain, conjunctivitis (red eyes), headache, and muscle pain. The illness is usually mild and the symptoms typically last several days to a week.

How soon do symptoms occur?
Symptoms, if present, can appear within 3 to 14 days after exposure to Zika virus.

How dangerous is Zika?
Zika virus infection during pregnancy can cause microcephaly and other severe birth defects. This does not mean that all women who have Zika virus infection during pregnancy will have babies with health problems. Microcephaly is a birth defect in which a baby's head is much smaller than expected. Some babies that were infected with Zika may be born with a normal size head, but have slowed head growth and later develop microcephaly. Other birth defects in fetuses and infants include damage to the brain, vision problems, hearing loss, limb defects, and slowed growth or development. In a small number of infected people, there have also been reports of neurologic syndromes, such as Guillain-Barré Syndrome. Studies are underway to learn more about health conditions associated with Zika virus and the effects of Zika virus infection during pregnancy.

What special precautions should pregnant women take to prevent Zika?
Pregnant women should not travel to areas with risk of Zika. For a map of where Zika is occurring, see CDC's Zika webpage: http://www.cdc.gov/zika/geo/index.html. If a pregnant woman must travel to an area with risk of Zika, she should talk to her healthcare provider and take the following steps to prevent Zika infection:

Prevent mosquito bites
Choose an EPA-registered insect repellent with one of the following active ingredients: DEET, picaridin, IR3535, oil of lemon eucalyptus or para-menthane-diol, or 2-undecanone, and use the repellent according to the product label. When used as directed, EPA-registered insect repellents are proven safe and effective even for pregnant and breastfeeding women. Use the repellent day and night because the mosquitoes that transmit Zika virus bite during the day, but will also enter buildings and bite at night. Use permethrin-treated clothing. Cover exposed skin by wearing long sleeves, pants, and hats. Sleep indoors in rooms with screened windows or air-conditioning, or use a bed net if you sleep in a room that is exposed to the outdoors.

Practice safe sex
For the rest of the pregnancy, use a condom every time during sex or do not have sex to prevent Zika and other sexually transmitted infections.
After returning, she should talk to her healthcare provider about her travel to an area with risk of Zika.

What special precautions should couples trying to become pregnant take to prevent Zika?
Couples trying to become pregnant should consider avoiding travel to areas with risk of Zika, or waiting to get pregnant if you travel to or live in an area with risk of Zika. For a map of where Zika is occurring, see CDC's Zika webpage: http://www.cdc.gov/zika/geo/index.html. If a member of the couple travels to an area with risk of Zika, the couple should take these steps to prevent Zika infection: Follow the same recommended steps for pregnant women to prevent mosquito bites (above) Wait for a period of time before trying to become pregnant. If only the female partner traveled, the couple should wait at least 2 months from when symptoms began (if sick) or after returning from travel (if not sick). If only the male partner traveled, the couple should wait at least 6 months from when symptoms began (if sick) or after returning from travel (if not sick). If both partners traveled, the couple should wait 6 months from when symptoms began (if sick) or after returning from travel (if not sick). While waiting to conceive, couples should either avoid sex or use condoms every time during sex or sexual activities.

What is the treatment for Zika?
There is no specific treatment for Zika virus infection. Healthcare providers primarily provide supportive care to relieve symptoms. This may include rest, fluids, and of over-the-counter medicine, such as acetaminophen. During the mosquito season in Virginia (May to October), people with Zika should also stay indoors or wear protective clothing and mosquito repellent for the first week after they begin to feel sick. This will help prevent mosquitoes in Virginia from becoming infected and spreading the virus.

How can Zika be prevented?
There is no vaccine to prevent Zika. Infections can be prevented by avoiding mosquito bites and sexual exposure to the virus. Avoiding mosquito bites includes wearing long-sleeved shirts, long pants and socks, using insect repellent or permethrin-treated clothing (especially during the daytime when mosquitos are active), using air conditioning or window/door screens to keep mosquitoes outside, and eliminating standing water from containers in yards (including bird baths, flower pots, buckets) to stop mosquito breeding. People who have returned from travel to an area with risk of Zika should also follow steps to avoid mosquito bites for 3 weeks after returning to prevent them from passing Zika virus to local mosquitoes that could spread the virus to others. To prevent sexual exposure to Zika virus, travelers to areas with risk of Zika and their sex partners should abstain from sex or use condoms during sex or sexual activities for the same timeframes as couples that are trying to become pregnant (above).

What should I do if I think I have Zika?
If you think you have Zika, see your healthcare provider. Your healthcare provider may test your blood or urine for Zika virus and other similar conditions.

Where can I get more information?
If you have concerns about Zika, contact your healthcare provider. You may also call your local health department. A directory of local health departments can be found at: http://www.vdh.virginia.gov/local-health-districts/.