Patient education: Zika virus infection (The Basics)

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What is Zika? — Zika is a type of virus. Infection with Zika can cause fever, rash, joint pain, and red eyes. Zika virus is spread mainly through mosquito bites. You can also get it by having sex with someone who is infected, even if they don't have symptoms. Spread is also possible in other ways, including from a pregnant person to their unborn baby, and through donated blood or organs.

If you have Zika while you are pregnant, it can cause serious problems for your baby. If you are not pregnant or planning to get pregnant, Zika is not likely to make you very sick or cause serious problems.

Where is Zika found? — In 2015 and 2016, there was a Zika virus outbreak in the Americas, the Caribbean, and the Pacific. In the Americas, most cases were in South America, Central America, and Mexico. The virus was also found in Florida and Texas, and the United States territories of Puerto Rico, the Virgin Islands, and American Samoa.

For the most current information about which parts of the world have Zika virus, go to 1 of these websites:

●United States Centers for Disease Control and Prevention (CDC): www.cdc.gov

●World Health Organization (WHO): www.who.int

What are the symptoms of Zika? — Many people infected with Zika have no symptoms, or only mild symptoms. If there are symptoms, they usually happen 2 to 14 days after being infected.

Symptoms might include:

●Fever

●Rash

●Pain in the joints, especially in the hands and feet

●Red eyes

●Headache

Zika can also lead to serious problems in babies whose mothers have the infection while they are pregnant.

In some areas where there is Zika virus, there have also been more cases of a disease called "Guillain-Barré syndrome" (or "GBS"). This is a condition that causes muscle weakness, which can sometimes be severe and even lead to paralysis. (Paralysis means you cannot move some muscles at all.) GBS seems to be caused by Zika in some cases, although most people who get Zika will not get GBS. Some people with Zika have other problems with the nerves or brain. But this is also rare.

What if I am pregnant? — If you get infected with Zika while you are pregnant, you could pass the infection on to your baby. This can happen even if you don't have symptoms, or only have mild symptoms. If you are pregnant or trying to get pregnant, experts say you should avoid traveling to areas where there is Zika virus. If you do visit these areas, it's especially important to try to avoid mosquito bites. It's also important to avoid having unprotected sex with anyone who has Zika virus. (See 'Can Zika be prevented?' below.)

Zika can cause serious problems in pregnancy, including miscarriage (when a pregnancy ends on its own before 20 weeks), stillbirth (when the baby dies before it is born), and birth defects. If you are pregnant and were recently in 1 of the areas where there is Zika, tell your doctor or nurse. Also tell them if you have had unprotected sex with anyone who has (or might have) Zika. Depending on your situation, your doctor might want to test you for the virus. They can do tests to see if your baby is likely to have it, too.

How does Zika affect babies? — Some babies whose mothers had Zika do not have problems, but many do. These problems can include:

●A head and brain that are smaller than usual (called "microcephaly")

●Seizures

●Muscle weakness or stiffness

●Feeding problems (for example, not sucking or swallowing well)

●Trouble hearing

●Eye problems

●Learning problems

●Other problems with growth and development

Babies whose mothers had Zika during pregnancy should get regular checkups. At these visits, they should have their hearing, vision, and development checked. It is important to keep getting these checkups through early childhood. This way the doctor can see if problems are getting better or worse, and check for any new problems.

What if I want to get pregnant in the future? — If you are thinking about having a baby, talk to your doctor. They can help you plan for a healthy pregnancy. If you or your partner live outside the areas where Zika is found, but have been to any of these areas, read the advice below on how to prevent the spread of Zika through sex. This includes guidelines about how long to wait before trying to get pregnant. (See 'Can Zika be prevented?' below.)

Can I get Zika through sex? — Yes, it's possible to get Zika through sex. If you or your partner has been to an area where there is Zika virus, it's a good idea to use a condom for any kind of sex. This includes vaginal, anal, and oral sex. It is possible for you to be infected with Zika and pass it on to your partner without even knowing you have it.

See below for more on preventing the spread of Zika through sex. (See 'Can Zika be prevented?' below.)

Should I see a doctor or nurse? — Yes. If you live in (or recently visited) an area where Zika is found, see a doctor or nurse if you have symptoms or if you are pregnant.

Is there a test for Zika? — Yes. If your doctor or nurse thinks you might have Zika, they can order tests to look for the virus. They might also do tests for other diseases that have similar symptoms.

If you have been to an area where there is Zika while pregnant, your doctor or nurse will talk to you about whether you should get tested. If you do not have any symptoms of Zika, you might not need testing. The decision will depend on where you live, how much time you have spent in areas where Zika is found, and your preferences.

How is Zika treated? — There is no specific treatment for Zika virus infection. If your symptoms bother you, you should rest and drink plenty of fluids. You can also take acetaminophen (sample brand name: Tylenol) to relieve fever and aches.

Do not take aspirin or NSAIDs, such as ibuprofen (sample brand names: Advil, Motrin) or naproxen (sample brand name: Aleve), unless your doctor or nurse says it's OK. That's because they can cause bleeding in people who have a disease that is similar to Zika, called "dengue fever." Blood tests can tell your doctor or nurse if you have dengue fever, Zika, or something else.

Never give aspirin or medicines that contain aspirin to children younger than 18 years. In children, aspirin can cause a serious problem called Reye syndrome.

Can Zika be prevented? — Yes. The best way to prevent Zika virus infection is to avoid the mosquitoes that carry it. Not all countries where Zika is common control mosquitoes well. But you can lower your chances of getting the infection if you live or travel there. The table has some tips for avoiding mosquitoes (table 1).

It's also important to try to avoid mosquito bites if you have already gotten Zika. That's because during the first week of having it, the virus can be found in your blood. If a mosquito bites you, and then bites another person, that person could then get Zika too.

Zika can be spread through sex, too. It's important to avoid unprotected sex if you or your partner might have been exposed to the virus. "Exposed" means living in or traveling to an area where there is Zika, or having unprotected sex with someone who has.

Some experts suggest the following guidelines, which are especially important for people who could get pregnant (and their partners). These guidelines are for people who do not live in areas with Zika virus:

●Males who might have been exposed to Zika should use condoms, or not have sex, for at least 3 months. The 3 months should begin after your symptoms start (if you have symptoms) or after the last possible exposure (if you don't).

●Females who might have been exposed to Zika should use condoms, or not have sex, for at least 8 weeks. The 8 weeks should begin after your symptoms start (if you have symptoms) or after the last possible exposure (if you don't).

●Everyone who might have been exposed to Zika and whose partner is pregnant should use condoms, or not have sex, for the rest of the partner's pregnancy. This is especially important, even if the person does not have symptoms.

For people who live in areas where there is Zika, experts suggest continuing to use condoms for as long as the outbreak is happening.

Another way Zika can be spread is through donated blood or tissues. If you want to donate blood, stem cells, eggs, or sperm, and have been to an area where there is Zika virus or had sexual contact with someone who has, tell the donation center staff. Then they can decide how long you should wait before donating.

There is not yet a vaccine for Zika virus infection, although experts are working on this.