Zika Virus


Overview Of Zika Virus

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

Commonly Associated With

Zika virus infection; Zika

Causes Of Zika Virus

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


Mosquitoes spread the virus from person to person.

Mosquitoes acquire the virus when they feed on infected people. They then spread the virus when they bite other people. The mosquitoes that spread Zika are the same type that spread dengue fever and chikungunya virus. These mosquitoes usually feed during the day.

Zika can be passed from a mother to her baby. This can happen in the uterus or at the time of birth. Zika has not been found to spread through breastfeeding. The virus can be spread through sex. People with Zika can spread the disease to their sex partners before symptoms begin, while they have symptoms, or even after symptoms end. The virus can also be passed during sex by people with Zika who never develop symptoms.

No one knows how long Zika remains in sperm and vaginal fluids, or how long it can be spread during sex. The virus remains in semen longer than in other body fluids (blood, urine, vaginal fluids).

Zika can also be spread through:

  • Blood transfusion
  • Exposure in a laboratory


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 has now spread to many territories, states, and countries in:

  • Caribbean Islands
  • Central America
  • Mexico
  • South America
  • Pacific Islands
  • Africa
  • 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. Zika has also been discovered in one area in Florida, where the virus is being spread by mosquitoes.

Symptoms Of Zika Virus

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:

  • Fever
  • Rash
  • Joint pain
  • Red eyes (conjunctivitis)
  • Muscle pain
  • Headache
  • Symptoms are usually mild and last for a few days to a week before going away entirely.

Exams & 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. You also may be tested for other viruses spread by mosquitoes, such as dengue and chikungunya.

Treatment Of Zika Virus

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

  • Drink plenty of fluids to stay hydrated.
  • Get plenty of rest.
  • Take acetaminophen (Tylenol) to relieve pain and fever.
  • Do not take aspirin, ibuprofen (Motrin, Advil), naproxen (Aleve, Naprosyn), or any other nonsteroidal anti-inflammatory drugs (NSAIDs) until your provider confirms that you do not have dengue. These medicines can cause bleeding in people with dengue.