Health Library

What Is Zika Virus?

Zika is a virus that a person can catch through the bite of an infected mosquito. Outbreaks of the virus have happened throughout the world, particularly in tropical areas where certain types of mosquitoes live.

The virus is of most concern for pregnant women and those who may become pregnant. In pregnant women, the virus can cause miscarriages, stillborn babies, or babies born with birth defects. One serious birth defect caused by Zika (ZEE-kuh) is microcephaly (the medical word for small head). When a baby has microcephaly, the brain and skull don’t grow properly and the baby may have delayed development. Zika also has been linked to other serious problems in babies, such as eye problems, hearing loss, and seizures.

Healthy children who get a Zika infection will not develop microcephaly. Only babies infected from Zika before they’re born are at risk for problems with brain development. Pregnant women shouldn’t travel to places with Zika outbreaks, according to the CDC.

What Are the Signs & Symptoms of Zika?

Most people who are infected with Zika don’t have any symptoms. So people often don’t know they have the virus.

If Zika symptoms do happen, they’re usually very mild. People might notice these problems 2–14 days after a bite from an infected mosquito:

• fever
• rash
• joint pain, especially in the hands and feet
• muscle pain
• pinkeye
• headache

A very small number of people with Zika will develop Guillain-Barré syndrome, a rare condition that causes temporary muscle weakness and paralysis.

How Does Zika Virus Spread?

The most common way a person can get Zika is from being bitten by an Aedes aegypti or Aedes albopictus mosquito that’s infected with the virus. These mosquitoes live in places that have tropical or mild climates.

The virus also can spread through having sex without a condom with someone with the virus, even if that person does not have symptoms.

Because the Zika virus can pass from an infected mom-to-be to her unborn baby, it’s important to take precautions if you’re pregnant or think you might become pregnant. If you live in or visit an area with Zika outbreaks, do your best to prevent mosquito bites and use condoms to prevent getting Zika through sex.

Zika virus infections are unlikely to spread through breastfeeding. The CDC encourages mothers to keep breastfeeding, even if they have Zika or have visited or live in an area with Zika. But as a precaution, breastfeeding women should still avoid possible exposure to the virus.

Zika virus isn’t as contagious as some other viruses. It doesn’t spread from person to person through sneezes and coughs, as colds and the flu do. People can’t get Zika from casual contact, like holding hands.

Where Is Zika?

The CDC has confirmed Zika outbreaks in:

• The Caribbean
• Mexico
• Central America
• South America
• Pacific Islands
• Africa
• Asia

Zika-spreading mosquitoes have been found in parts of the United States and its territories, but there currently is no transmission of Zika in the United States. Check the CDC’s website for the latest news.

How Is Zika Diagnosed?

Doctors can check people for Zika by doing blood tests or urine (pee) tests.

Pregnant women or women who might become pregnant should contact their doctor if they think they might have been exposed to Zika, even if they don’t have symptoms.

How Is Zika Treated?

Most people with Zika infection get better in 2 to 7 days by resting at home and drinking lots of fluids. Give kids acetaminophen to help with fever and aches. Never give aspirin to kids or teens, especially during viral illnesses. This can lead to a serious illness called Reye syndrome.

Because some over-the-counter (OTC) medicines contain aspirin, always read labels and check with your doctor before using them. Some aspirin-containing medicines use words other than aspirin (such as salicylate or acetylsalicylate), so avoid those too.

Antibiotics only work for bacterial infections, not viral infections like Zika.

Can Zika Be Prevented?

There is no vaccine for Zika virus. If you’re pregnant or thinking about becoming pregnant, the best ways to protect yourself are to avoid mosquito bites and take precautions when having sex. Pregnant women should not travel to areas with a Zika outbreak.

To avoid mosquito bites if you live in or visit areas with Zika outbreaks:

• Cover up skin. Wear long-sleeved shirts and long pants. Clothing that’s been sprayed or treated with an insect repellent called permethrin offers added protection.
• Stay indoors. Keep windows closed in homes that have air conditioning, or install window screens and make sure they have no holes.
• Use insect repellent. Choose one that’s 10% to 30% DEET. Read and follow all directions and precautions. Don’t use it on babies younger than 2 months.

  Picaridin is another kind of mosquito repellent that the CDC says can be used. And oil of lemon eucalyptus is safe to use on kids 3 years and older.

• Get rid of standing water. Drain containers of standing water (such as children’s swimming pools, flower pots, or buckets) where mosquitoes can breed.

Couples trying to get pregnant who visit places with Zika outbreaks should consider waiting to get pregnant. Because the virus can spread through sex, men should use condoms.

• If a woman gets a Zika infection or has traveled to a Zika-infected area, the couple should wait at least 2 months before trying to get pregnant.
• If a man gets a Zika infection or has traveled to a Zika-infected area, the couple should wait at least 3 months before trying to get pregnant.
• If the couple has traveled to a Zika-infected area or the male partner gets a Zika infection, the couple should wait at least 3 months before trying to get pregnant.

Couples who are already pregnant who live in or visited places with Zika outbreaks shouldn’t have sex during pregnancy or should always use a condom.

Even couples who are not pregnant or trying to become pregnant should use a condom during sex for at least 3 months after either of the partners has traveled to a Zika-infected area.

When Should I Call the Doctor?

Women who are pregnant (or think they might be pregnant) should call their doctor if they’ve been in areas with Zika or have Zika symptoms.