Zika Virus

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History and Spread of Zika

The Zika virus, originally identified in 1947 from the Zika forest of Uganda, is transmitted to people primarily through the bite of an infected Aedes species mosquito. These mosquitoes are found throughout tropical regions of the world and are the same mosquitoes that spread the dengue and chikungunya viruses. Mosquitoes become infected with the Zika virus when they feed on a person already infected with the virus. Infected mosquitoes can then spread the virus to other people through bites. There is no vaccine to prevent or medicine to treat Zika virus infection.


Local, state and federal health agencies are monitoring the spread of Zika virus through reports of possible human cases since the Zika virus must first be introduced into a mosquito population by someone who is infected.

If a positive case for the Zika virus is reported in the community, Richardson Health Department workers will follow Centers for Disease Control protocol by treating the area for mosquitos in and around the home of the individual or individuals reported. Because the mosquito connected with carrying the Zika virus does not travel far, the area is treated to significantly reduce the mosquito population of those mosquitoes that may have come in contact with an infected individual.

Visit a doctor if you have recently traveled abroad to areas where the Zika virus is reported and are showing symptoms.


The Zika virus can be transmitted in the following ways:

Through Mosquito Bites
The Zika virus is transmitted to people primarily through 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.
From Mother to Child
A pregnant woman can pass the Zika virus to her fetus during pregnancy. To date, there are no reports of infants getting the Zika virus through breastfeeding.
Through Sexual Contact
The Zika virus can be spread through sexual activity. The virus can be spread before symptoms start and after symptoms resolve. It is unclear how long the virus is present in semen.
Through Blood Transfusion
As of Feb. 1, 2016, there have not been any confirmed blood transfusion transmission cases in the United States but there have been multiple cases reported in Brazil.
Infographic showing additional information about the Zika virus. All information is provided in other areas on this web page.
  • Avoid travelling to areas where Zika outbreaks are occurring.
  • Avoid mosquito bites through effective use of mosquito repellants or proper clothing.
  • If your sexual partner has traveled to areas with Zika, use condoms even if they do not feel sick.
  • The CDC does not yet know how long the virus can stay in semen.

Approximately 80 percent of people infected with the Zika virus do not become ill. For those who do develop symptoms, illness is generally mild and typically lasts a few days to a week. The most common symptoms of Zika virus disease are fever, rash, joint pain and conjunctivitis (red eyes). Other common symptoms include muscle pain and headache. The incubation period (the time from exposure to symptoms) for Zika virus disease is not known, but is likely to be a few days to a week.

Traveling while Pregnant

Women who are pregnant should not travel to areas with Zika. If you must travel to one of these areas, talk to your healthcare provider first and strictly follow steps to prevent mosquito bites during your trip.

See your health care provider if you are pregnant and develop a fever, rash, joint pain or red eyes within two weeks after traveling to a place where Zika has been reported. Be sure to tell your health care provider where you traveled.

  • The illness is usually mild with symptoms lasting for several days to a week after being bitten by an infected mosquito.
  • People usually don’t get sick enough to go to the hospital, and they very rarely die of Zika. For this reason, many people might not realize they have been infected.
  • Zika virus usually remains in the blood of an infected person for about a week but it can be found longer in some people.
  • Once a person has been infected, he or she is likely to be protected from future infections.

The U.S. Centers for Disease Control and Prevention (CDC) is currently advising pregnant women to delay travel to foreign countries where Zika is being transmitted. To prevent the spread of the disease, people traveling to those areas should carefully follow steps to avoid mosquito bites while there and for seven days after returning home.

Attempting Pregnancy

The Centers for Disease Control and Prevention have several recommendations for women trying to become pregnant. For more information and steps to protect yourself, please visit the "For Pregnant Women" section of the Official CDC Zika Website.


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

Treat the symptoms:

  • Get plenty of rest.
  • Drink fluids to prevent dehydration.
  • Take medicine such as acetaminophen/paracetamol (Tylenol®) to relieve fever and pain.
  • Do not take aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs).
  • If you are taking medicine for another medical condition, talk to your health care provider before taking additional medication.
  • If you have Zika, prevent mosquito bites for the first week of your illness.
  • During the first week of infection, Zika virus can be found in the blood and passed from an infected person to a mosquito through mosquito bites.
  • An infected mosquito can then spread the virus to other people.
More Information

Centers for Disease Control

Zika in Texas - Texas Department of State Health Services

The City practices integrated mosquito control with the intent to disrupt the mosquito life cycle in its early stages to eliminate the number of adults and mosquito breeding habitats through proper water drainage. Mosquito control activities are conducted year-round but are increased from April through October, the most active mosquito season in North Texas.

How to Protect Yourself
Follow the Four D's of protection:

  • DRAIN standing water around the home
  • Use insect repellent containing DEET
  • Avoid being outdoors at DUSK and DAWN
  • DRESS to protect yourself with long sleeves and pants