Zika is a mosquito-borne virus. It was first discovered in the Zika Forest of Uganda in 1947. For many decades, it was thought to be a rare cause of viral infection. It was found only in small areas of Africa, the Yap Islands in the Pacific, and Easter Island. But in April 2015, it was found in Brazil. It has since spread quickly to many countries in South America and Central America, and to the Caribbean and Mexico.
A number of cases have also been found in the U.S. Most of these people got the virus while visiting other parts of the world where mosquitoes are spreading it. But in some cases the virus had been spread by mosquitoes in the U.S.
The Zika virus is mostly passed on by the bite of the mosquito species Aedes. Pregnant women who have it can also pass it on to their unborn child. People may also get it through sexual contact and blood transfusion.
The time it takes from exposure to the Zika virus to the appearance of symptoms (called the incubation period) is not definite, but it is believed to be a few days. But most people infected with the Zika virus have no symptoms. For the 1 out of 5 people who do have symptoms, they are often very mild. They last 2 to 7 days and then go away completely. They may include:
Extreme tiredness (fatigue)
Joint and muscle pain
Conjunctivitis, when the eyes become red, irritated, and inflamed
Blood or urine testing can detect the Zika virus. Pregnant women who live in or have traveled to areas where the virus is active, or who are sexually active without a condom with someone who lives in or traveled to a Zika area, should talk with their healthcare provider about if they should be tested. More testing may be needed to check on the health of the unborn child, or the health of a newborn whose mother has recently traveled to those areas. Anyone who is not pregnant but may have been exposed to the Zika virus, or has current or recent symptoms of Zika, should also be tested.
Experts update information weekly on who should be tested. Check the CDC website for the latest advice.
There is no medicine to cure the Zika virus. Treatment is aimed at easing symptoms. Rest and drinking plenty of fluids are helpful. Acetaminophen can help ease fever and pain.
For pregnant women, Zika can be a far more serious concern. A woman can pass the virus on to her unborn child. This is true even if she has no symptoms. The virus can cause a condition called microcephaly in these infants. Babies with this serious birth defect are born with a smaller than normal head and a less developed brain. That can lead to developmental problems, learning disabilities, and neurological problems. These risks have led the CDC to issue recommendations that pregnant women not travel to areas with active Zika virus transmission.
The Zika virus may also very rarely cause Guillain-Barré syndrome (GBS) in adults. GBS causes muscle weakness or paralysis. If the muscle weakness is severe enough or widespread enough, the person may need to use a machine to breathe (ventilator). Most people with GBS recover. But it may take months. Sometimes recovery is not complete. Researchers are looking more closely at the possible link between Zika and GBS.
Zika can be prevented in the same way as other mosquito-borne diseases. That means taking steps to protect against mosquito bites:
Wear long-sleeved shirts and pants when outdoors in areas where mosquitoes are active.
Put on insect repellent before going outdoors.
Use air conditioning or screens on doors and windows to keep mosquitoes out of your home.
Empty water from any containers so mosquitoes have fewer places to breed. Even small items like bottle caps can hold enough water for mosquitoes to multiply.
Don’t travel to places where there is a Zika outbreak, especially if you are pregnant or plan to become pregnant.
If you have traveled to an area where Zika is found, or you have already been infected with the virus, practice safe sex. Use a condom for at least 6 months so that you don’t spread the virus.
Zika virus infections are new—at least in their current widespread form. If you plan to travel to places with known Zika outbreaks get the latest travel recommendations from the CDC website or the World Health Organization (WHO) website before you go.
Zika is a mosquito-borne virus.
The virus has spread quickly to many countries in South America and Central America, the Caribbean, and Mexico. Many cases have also been found in the U.S.
The Zika virus is mostly passed on by the bite of the mosquito species Aedes. People may also get it through sexual contact and blood transfusion.
A pregnant woman can pass the virus on to her unborn child, even if she has no symptoms. The virus can cause a birth defect called microcephaly.
There is no medicine to cure the Zika virus. Treatment is aimed at easing symptoms.
Article Last Updated: February 12, 2019
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