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Zika virus disease

Zika virus infection; Zika virus; Zika

Zika is a virus passed to humans by the bite of infected mosquitoes. Symptoms include fever, joint pain, rash, and red eyes (conjunctivitis).


The Zika virus is named after the Zika forest in Uganda, where the virus was first discovered in 1947.


Mosquitoes spread the Zika virus from person to person.

Zika can be passed from a mother to her baby.

The virus can be spread through sex.

Zika can also be spread through:


Before 2015, the virus was found mainly in Africa, Southeast Asia, and the Pacific Islands. In May 2015, the virus was discovered for the first time in Brazil.

It spread to many territories, states, and countries in:

The virus was confirmed in Puerto Rico, American Samoa, and United States Virgin Islands.

The disease has been found in travelers coming to the United States from affected areas.

However, there are no documented cases of Zika at this time in the United States.

To find the most up-to-date information on area where Zika may be found, please see the CDC page Zika Travel Information.


Only about 1 in 5 people infected with Zika virus will have symptoms. This means that you can have Zika and not know it.

Symptoms tend to occur 2 to 7 days after being bitten by an infected mosquito. They include:

Symptoms are usually mild, and last for a few days to a week before going away entirely.

Exams and Tests

If you have symptoms of Zika and have recently traveled to an area where the virus is present, your health care provider may do a blood test to check for Zika. You also may be tested for other viruses spread by mosquitoes, such as dengue and chikungunya.


There is no treatment for Zika. Like the flu virus, it has to run its course. You can take steps to help relieve symptoms:

Possible Complications

A Zika infection during pregnancy can cause a rare condition called microcephaly. It occurs when the brain does not grow as it should in the womb or after birth and causes babies to be born with a smaller-than-normal head.

Intense research is currently being done to understand how the virus may spread from mothers to unborn babies and how the virus may affect babies.

Some people infected with Zika have later developed Guillain-Barré syndrome. It is unclear why this may occur.

When to Contact a Medical Professional

Call your provider if you develop symptoms of Zika. Let your provider know if you have traveled recently in an area where the virus is spread. Your provider may do a blood test to check for Zika and other mosquito-borne illnesses.

Call your provider if you or your partner has been to an area where Zika is present or live in an area with Zika and you are pregnant or thinking about becoming pregnant.


There is no vaccine to protect against Zika. The best way to avoid getting the virus is to avoid getting bitten by mosquitoes.

The CDC recommends that all people traveling to areas where Zika is present take steps to protect themselves from mosquito bites.

When you return from travel to an area with Zika, you should take steps to prevent mosquito bites for 3 weeks. This will help ensure you don't spread Zika to mosquitoes in your area.

The CDC makes these recommendations for women who are pregnant:

The CDC makes these recommendations for women who are trying to become pregnant:

The CDC makes these recommendations for women and their partners who are NOT trying to become pregnant:

Zika can't be spread after the virus has passed from the body. However, it's unclear how long Zika may remain in vaginal fluids or semen.

Areas where the Zika virus occurs are likely to change, so be sure to check the CDC website for the most recent list of countries affected and for the latest travel advisories.

All travelers to risk areas for Zika should avoid getting mosquito bites for 3 weeks after returning, to prevent the spread of Zika to mosquitoes that could spread the virus to other people.


Centers for Disease Control and Prevention website. Zika virus. Updated February 25, 2022. Accessed June 6, 2022.

Johansson MA, Mier-Y-Teran-Romero L, Reefhuis J, Gilboa SM, Hills SL. Zika and the risk of microcephaly. N Engl J Med. 2016;375(1):1-4. PMID: 27222919

Oduyebo T, Polen KD, Walke HT, et al. Update: interim guidance for health care providers caring for pregnant women with possible Zika virus exposure - United States (Including U.S. Territories), July 2017. MMWR Morb Mortal Wkly Rep. 2017;66(29):781–793. PMID: 28749921

Polen KD, Gilboa SM, Hills S, et al. Update: interim guidance for preconception counseling and prevention of sexual transmission of Zika virus for men with possible zika virus exposure - United States, August 2018. MMWR Morb Mortal Wkly Rep. 2018;67:868-871. PMID: 30091965


Review Date: 3/10/2022  

Reviewed By: Jatin M. Vyas, MD, PhD, Associate Professor in Medicine, Harvard Medical School; Associate in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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