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Zika Virus

Zika virus is a generally mild illness that is spread primarily through the bite of an infected mosquito. Zika virus occurs in tropical areas with large mosquito populations, and is known to circulate in Africa, Southeast Asia, the Pacific Islands, South America, Central America, the Caribbean and Mexico. To see a map of currently affected areas, visit the CDC's website.

Zika virus is spread primarily to people through the bite of an infected Aedes species of mosquito. Zika virus cannot be transmitted through casual contact.

The current Zika virus outbreak began in May 2015 in Brazil, leading to reports of a neurological disease called Guillain-Barré syndrome and pregnant women giving birth to babies with birth defects such as microcephaly. The outbreak has spread to numerous countries and areas, prompting the Centers for Disease Control and Prevention (CDC) to issue travel notices to regions where the Zika virus transmission is ongoing. In response to the emerging disease, Pennsylvania has created a Zika Response Plan.

What are the symptoms of Zika virus?

It is not clear how long it takes to become ill after being bitten by an infected mosquito, but it is likely between three to twelve days.

The most common symptoms, which are usually mild and last for two to seven days, include:  

  • Fever;
  • Rash;
  • Muscle and/or joint pain;
  • Conjunctivitis (red eyes). 

How is Zika virus diagnosed?

Symptoms of Zika virus are similar to several other diseases, so diagnosing Zika virus requires a blood and/or urine test.

See your health care provider if you develop the symptoms described above and have visited an area where Zika is found. Tell your provider when and where you traveled. 

How does Zika virus spread?

Zika virus is mainly spread from the bite of an infected mosquito to a person. Zika virus can spread through sexual contact from a partner who has been infected with Zika virus. Although less common, Zika virus can also be spread from a mother to baby during pregnancy or during the time of birth or through blood transfusion.

How dangerous is Zika virus?

Most people infected with Zika virus have mild symptoms (or no symptoms at all). However, pregnant women who are infected with Zika virus have a greater risk of babies born with microcephaly, a birth defect where the baby's head is smaller than expected, or other birth defects. Guillain-Barré Syndrome, a rare but severe and progressive neurological disorder, has been reported to be associated with Zika virus infection. People rarely die from Zika virus.

Is there a treatment or a vaccine for Zika virus?

There are no vaccines or medications available to prevent or treat Zika virus. If you are ill with symptoms of Zika virus: 

  • Get plenty of rest.
  • Drink fluids to prevent dehydration.
  • Acetaminophen may be helpful to relieve fever and pain. Do not take aspirin or other non-steroidal anti-inflammatory drugs (NSAIDS), like ibuprofen and naproxen, until dengue virus infection is ruled out.

Is it safe for me to travel to other countries?

The CDC has issued travel notices for regions where Zika virus transmission is a risk. Zika travel notices include certain countries in South America, Central America, the Caribbean, the Pacific Islands, Africa and Southeast Asia. Within the U.S., there are currently no travel notices.

Travelers to these destinations should take extra steps to protect themselves from mosquito bites.

Pregnant women, or women planning to become pregnant, should avoid travel to regions with active Zika virus transmission.

How can I protect myself from Zika virus?

The best way to prevent Zika is to avoid mosquito bites. To do this:

  • Use an EPA-registered insect repellent. EPA-registered repellents are safe for pregnant women and children to use, but be sure to check the product label for any warnings and follow the instructions closely.
  • When indoors, use air conditioning, window screens or insecticide-treated mosquito netting to keep mosquitoes out of the home.
  • Reduce the number of mosquitoes outside the home or hotel room by emptying or routinely changing standing water from containers such as flowerpots, pet dishes and bird baths. 
  • Wear long sleeves and pants when outdoors.

You can also protect yourself by avoiding sexual contact with a partner who traveled to a Zika-affected area or use a condom (or other barrier to prevent infection) correctly each time you have sex.

Have there been cases of Zika virus in Pennsylvania?

There have been cases in travelers who have returned from areas where Zika virus is common. Local transmission of Zika virus (virus acquired from local mosquitoes) has not been identified in Pennsylvania. 

Can my pets get Zika virus?

There have been no reports of pets or other types of animals becoming sick with Zika virus.

What should I do if I think I have Zika?

Contact your health care provider if you developed symptoms of Zika virus within two weeks after returning from travel to a Zika-affected area or had recent sexual contact with a partner who was exposed to Zika virus. Your health care provider may test your blood and/or urine for Zika virus and other similar illnesses.

If you are pregnant and traveled to a Zika-affected area within the last 12 weeks and have experienced symptoms associated with Zika virus, your health care provider may test your blood and/or urine for Zika virus.

I have Zika virus. How can I protect others from getting sick?

When you are infected with Zika, the virus can be found in your blood and passed to a mosquito that bites you. An infected mosquito can then spread the virus to other people. This process is called human-to-mosquito-to-human transmission. To prevent others from getting sick, strictly avoid all mosquito bites for three weeks. 

Zika virus can also be spread during sex by a partner infected with Zika virus to his or her sex partner(s). To prevent Zika from spreading, use condoms (or other barriers to prevent infection) correctly every time you have sex or abstain from sex. How long to continue using a condom or waiting to have sex depends on each couple’s situation and concerns. For couples whose beliefs and cultural values may influence contraceptive decision-making, discuss with your doctor alternate methods to prevent pregnancy.

Zika virus could also be spread through blood transfusions. If you have Zika virus, follow official guidelines on deferring blood donations.

What is Pennsylvania doing to protect its residents?

The Pennsylvania Department of Health and Department of Environmental Protection created a Zika Response Plan to prepare for Zika virus testing, to enhance surveillance and control of mosquito populations that can spread Zika virus, and to enhance surveillance for Zika cases in Pennsylvania.