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Skip Navigation LinksPennsylvania Department of Health > My Health > A-Z Health Topics > U-Z > Zika virus > About Zika Virus
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.
The virus was first discovered in 1947. Zika outbreaks have probably occurred in many locations in the past, but the first documented outbreak occurred in 2007. In May 2015, the current Zika virus outbreak started in Brazil. Since then, it has been reported in many other countries and territories. It will likely continue to spread to new areas.
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.

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).

Severe illness requiring hospitalization is uncommon. Deaths from Zika virus are rare.

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.

There have also been rare reports of Guillain-Barré Syndrome and other neurological conditions.

Diagnosing Zika Virus
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. 

Testing is available at most commercial labs. The Pennsylvania Department of Health can provide testing if certain criteria for testing have been reached.

Treating 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.