What is Zika virus?

Zika is a virus that is primarily spread by mosquitoes. It’s similar to West Nile virus and yellow fever. Zika has been spreading rapidly through tropical areas in South and Central America. The mosquitoes that carry it are mainly limited to the southern United States, but some can range as far north as New York, so experts expect the virus to become established here. Sexual transmission is also possible.

Most people who become infected have no symptoms, and when symptoms do occur, they’re usually mild. People may experience fever, muscle or joint pain, a rash and headaches. The virus usually clears up in a few days and causes no lasting damage.

Experts have become increasingly concerned about Zika, however, because it can cause a birth defect called microcephaly, in which babies are born with unusually small heads and brain damage. Many of these babies die in the womb or at birth, or are severely disabled. The defect has been increasing rapidly in areas that have had a major Zika outbreak, particularly Brazil. Other types of viruses can cause microcephaly if the mother is infected during pregnancy, especially during the first trimester. The Centers for Disease Control and Prevention (CDC) has advised pregnant women to avoid travel to areas where the outbreak is ongoing, or to take steps to avoid mosquito bites when they’re there.

It’s not easy yet to test for Zika virus. A blood, urine or tissue sample must be sent to an advanced lab for testing during the first weeks of the illness. No treatment or vaccine is available yet, so the best way to protect yourself is to avoid getting bitten: Wear long pants and sleeves when outside in the evening, use insect repellant and empty any areas of standing water on your property. 

Zika is a virus that is spread by a type of mosquito called Aedes aegypti. There are two reasons why we are seeing more Zika infections now:
  • more people are moving into areas where there are mosquitoes
  • global warming is encouraging these types of mosquitoes to grow (or breed)
The virus causes pink eye, fever, skin rash and joint pain. It might spread by having sex. If a pregnant women catches the virus, her baby may be born with an extremely small head (microcephaly) and brain damage. This devastating problem is most often seen when the mom-to-be is infected during the first 3 months of pregnancy, but may occur later.

Zika is a virus that is spread by a mosquito, and has been found mostly in Africa, Southeast Asia, and South and Central America. It is related to dengue and yellow fever viruses. The CDC recently issued a travel alert for Mexico, Central America, South America and the Caribbean due to its association with microcephaly, a severe birth defect. 

Dr. Sanjay Gupta, MD
Fitness Specialist

Zika is a virus that has been around since the late 1940s. It was identified in the primates in the Zika Forrest of Uganda. That’s where it got its name.

In the 1950s it was found in human beings. It started to spread in part because of the globalized world in which we live. Most likely, what happened is somebody who had the Zika virus in their system, but probably wasn’t sick, got on a plane, traveled to a place where the type of mosquitos that can spread Zika virus lived and that person got bit by a mosquito. That same mosquito subsequently bit somebody else and that started the transmission. On the little island of Yap in Micronesia, 73% of the population was infected.

From there, it started hopscotching and zigzagging around the world. When a population of people has never been exposed to a virus before, they don’t have any natural immunity to it. The body doesn’t try and fight it. When a virus shows up all of a sudden that a population has never seen before, it can spread much more quickly because it gets into the body and replicates itself. That makes it easier for mosquitoes to bite someone, take some of that virus into their body and then subsequently give it to somebody else. 

Zika virus is spread to people primarily through mosquito bites. Outbreaks of Zika have occurred in areas of Africa, Southeast Asia, the Pacific Islands, and the Americas. Because the Aedes species mosquitoes that spread Zika virus are found throughout the world, it is likely that outbreaks will continue to spread to new countries. Zika first appeared in Brazil in May 2015. In December 2015, the Commonwealth of Puerto Rico reported its first confirmed Zika virus case. Locally transmitted Zika has not been reported in the continental United States, but cases of Zika have been reported in returning travelers.

There have been reports of microcephaly (a birth defect in which the size of a baby's head is smaller than expected) and other poor pregnancy outcomes in babies of mothers who were infected with Zika virus while pregnant. However, additional studies are needed to further characterize this relationship. More studies are planned to learn more about the risks of Zika virus infection during pregnancy.

Until more is known, the CDC recommends special precautions for pregnant women and women trying to become pregnant:

  • Pregnant women in any trimester should consider postponing travel to the areas where Zika virus transmission is ongoing.
  • Pregnant women who do travel to one of these areas should talk to their doctor or other healthcare provider first and strictly follow steps to avoid mosquito bites during the trip.
  • Women trying to become pregnant should consult with their healthcare provider before traveling to these areas and strictly follow steps to prevent mosquito bites during the trip.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.