What is a Zika virus test?

A Zika virus test looks for signs of a Zika virus infection in a sample of your blood or urine (pee). The virus is mostly spread by mosquito bites. But you can get Zika if you have sex with a person who has Zika, even if they don't have symptoms. Using condoms may help prevent spreading Zika through sex.

A Zika infection during pregnancy can cause serious birth defects in the unborn baby. Most unborn babies who get Zika will not have birth defects. But when birth defects happen, they often affect the brain and eyes.

The main birth defect linked to Zika is microcephaly. Babies with microcephaly have smaller heads than normal because their brains don't develop properly. A Zika infection in pregnancy also increases the risk of other birth defects, miscarriage, premature labor, and stillbirth.

Most people who get Zika have no symptoms or only mild symptoms that last a few days to a week. In rare cases, Zika may lead to Guillain-Barré syndrome (GBS), a serious illness that weakens your muscles. With proper care, most people will recover from GBS over time.

Zika outbreaks come and go in different parts of the world. They tend to happen more often in tropical climates, including Africa, Southeast Asia, the Pacific Islands, parts of the Caribbean, and Central and South America. There have been outbreaks of Zika virus in the United States, but they have not been common.

Other names: Zika Antibody Test, Zika RT-PCR Test, Zika test

What is it used for?

If general, Zika virus testing is mostly used to diagnose a Zika infection if you:

• Have symptoms of Zika
• And have been in a part of the world where there is an active Zika outbreak. Sometimes your health care provider may recommend a test if you been to an area that has a risk for Zika outbreaks.

There are two types of tests are used to check for Zika infections:

• Molecular tests. These tests look for genetic material from the Zika virus. The tests are also called nucleic acid amplification tests (NAAT or NAT). A PCR test (polymerase chain reaction) is a common type of molecular test that checks for the Zika virus in a sample of your blood or urine. This test is recommended if you're pregnant.
• Antibody tests. Antibodies are proteins that your immune system makes to fight viruses and other germs. A Zika antibody test checks a sample of your blood for the antibodies that fight Zika. Your body needs time to make antibodies. So, to be accurate, an antibody test can be done starting within a week after symptoms begin.

Why do I need a Zika virus test?

Zika virus outbreaks tend to come and go. The recommendations for Zika testing are likely to change as outbreaks develop and disappear.

If you have symptoms of Zika and you have been in a part of the world where there is an active Zika outbreak, you need a Zika virus test.

If you are pregnant and:

• You have symptoms of Zika, you need a Zika virus test if:
  • You have recently traveled to an area outside of the U.S. where there is a risk of Zika (a country that has a current outbreak or has had Zika outbreaks in the past).
  • You have had sex with a partner who traveled to an area outside the U.S. where there is a risk of Zika.
• You have traveled to an area outside of the US where there is a risk of Zika, you may need a Zika virus test if:
  • Your provider sees problems on your baby's ultrasound that could be Zika.
  • You deliver a baby with birth defects that may have been caused by Zika.

Most people with Zika don't have symptoms, but when there are symptoms, they often include:

• Fever
• Rash
• Joint pain
• Muscle pain
• Headache
• Pink eye (conjunctivitis)

If you have symptoms of Zika and could have been exposed through sex with an infected person, contact your provider. Tell your provider about your possible exposure. Using condoms can reduce your chance of getting Zika from sex.

What happens during a Zika virus test?

A Zika virus test usually uses a sample of your blood or urine.

For a blood test: A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

For a urine test: Ask your health care provider for instructions on how to provide your sample.

Will I need to do anything to prepare for the test?

You don't any special preparations for a Zika virus test.

Are there any risks to the test?

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

There are no known risks to a urine test.

What do the results mean?

If you have a negative Zika virus result:

• On a molecular test, such as a PCR test, it means that you probably don't have a Zika infection. But you may need an antibody test to make sure you don't have Zika.
• On an antibody test, it means that you probably haven't had a recent Zika virus infection. But you may have been tested before your body had time to make enough antibodies to show up on the test. Your provider may suggest that you get tested again.

If you have a positive Zika virus test result:

• On a molecular test, such as a PCR test, it means that you most likely have a Zika infection. The test found genetic material from the Zika virus in your sample.
• On an antibody test, it means that you may have a Zika infection, but you may need another test to confirm the results. That's because some Zika antibody tests may not tell the difference between Zika antibodies and antibodies that fight similar viruses that mosquitos carry.

If you're pregnant and have a Zika infection, your provider will closely watch your pregnancy to see if Zika is affecting your baby. After birth, your baby will be tested for a Zika infection.

If you have a Zika infection and you're planning to get pregnant in the near future, talk with your provider about how long you should wait. At this time, there's no evidence that getting pregnant after recovering from Zika has risks for the baby.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about a Zika virus test?

If you are pregnant or planning to become pregnant, you should avoid traveling in areas where Zika infection is a risk. If that's not possible, be careful to protect yourself against mosquito bites.