Zika Virus

Zika is a virus transmitted by the bite of an infected Aedes mosquito. It typically causes a mild illness. Zika infection during pregnancy can cause a serious birth defect called microcephaly, as well as other severe fetal brain defects.


Zika is transmitted primarily by the bite of an infected Aedes species mosquito. These are the same mosquitoes that spread Dengue and Chikungunya viruses. These mosquitoes are aggressive daytime biters but can also bite at night. Mosquitoes become infected when they feed on a person already infected with the virus and can then spread the virus to other people through bites.

 From mother to child

  • A pregnant woman can pass Zika to her fetus during pregnancy
  • A pregnant woman already infected with Zika near the time of delivery can pass on the virus to her newborn
  • To date, there are no reports of infants contracting Zika through breastfeeding

Through infected blood or sexual contact 

  • The spread of Zika from blood transfusions have been reported in Brazil and during an outbreak in French Polynesia. These reports are currently being investigated.  
  • Zika can be spread by a man to his sex partners. The virus is present in semen longer than in blood.


Most people infected with Zika will not have symptoms, but for those that do, the symptoms are mild and last several days to a week after being bitten by an infected mosquito.

Common Symptoms

  • Rash
  • Joint pain
  • Conjunctivitis (red eyes)
  • Fever

Less Common Symptoms

  • muscle pain
  • headaches
  • vomiting
See a healthcare provider if you develop symptoms and have visited an area where Zika is found. The healthcare provider may order blood tests for Zika or other similar viruses. Healthcare providers may contact the Health Department at 610-344-6452 to facilitate testing.


There is no vaccine or medicine to prevent or treat Zika. 

Treat the symptoms

  • Get plenty of rest
  • Drink fluids to prevent dehydration
  • Take fever and pain relievers if needed such as acetaminophen. 
  • Do not take aspirin and other non-steroidal anti-inflammatory drugs until Dengue Fever can be ruled out to reduce the risk of bleeding.


Pregnant women should contact their healthcare provider if they or their male sex partners recently traveled to an area with Zika, even if they don’t feel sick.

Women and their partners who are thinking about pregnancy should talk with their doctor or healthcare provider about
  • plans for having children
  • potential risk of getting Zika during pregnancy
  • partner’s potential exposures to Zika
Use condoms or abstain from sex to prevent sexual transmission of Zika. 

If you are infected with Zika virus, protect yourself from mosquito bites. Mosquitoes spread Zika by biting an infected person and then passing their blood onto someone else through a bite. An infected mosquito can then spread the virus to other people.

Travel Notices

CDC has Zika travel notices posted for many destinations. If you are traveling to an area with Zika, be sure to follow CDC recommendations to stay healthy and safe. All travelers to areas with Zika should prevent mosquito bites. Zika can also be spread by a man to his sex partners, so travelers should use condoms if they have sex. 

Because Zika during pregnancy can cause serious birth defects, pregnant women should not travel to areas with Zika. Couples who are trying to become pregnant should talk to their doctor about their travel plans and see CDC guidance for how long you should wait to get pregnant after travel to an area with Zika. 

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