Zika Information


What is Zika virus infection?
Zika virus infection is a viral disease primarily spread to people through bites of infected mosquitoes, but sexual transmission has also been documented. Mosquitoes become infected by feeding on infected persons. Zika virus is transmitted primarily by Aedes aegypti (Yellow fever mosquito). Aedes albopictus (Asian tiger mosquito) can also spread the virus.

Where does Zika virus occur?
Outbreaks of Zika virus infection have occurred in Africa, Southeast Asia, the Pacific Islands, Central America, South America, the Caribbean and Mexico. For a map, see http://www.cdc.gov/zika/geo/index.html. Because the mosquitoes that spread the virus are found around the world, it is likely that outbreaks will spread to new countries. There has not been any reported mosquito-borne transmission of Zika virus in the continental U.S. For a map of where the mosquitoes that could spread Zika virus are located in the U.S., see http://www.cdc.gov/zika/vector/range.html.

Who gets Zika virus infection?
Anyone traveling to an area where Zika virus is found can become infected. Infections have been reported in travelers returning to the U.S. from affected areas. Those who do not travel to affected areas are not currently at risk of becoming infected because local spread by mosquitoes in the continental U.S. has not been reported.

What are the symptoms of Zika virus infections?
About 80% of people who are infected do not become sick. For the 20% who do become sick, the most common symptoms include fever, rash, joint pain, and conjunctivitis (red eyes). The illness is usually mild and the symptoms typically last several days to a week.

How soon do symptoms occur?
Evidence from case reports and experience from related flavivirus infections indicate that the incubation period for Zika virus disease is likely 3–14 days. This means that symptoms are likely to occur from 3 to 14 days after exposure to Zika virus.

How dangerous is Zika virus infection?
Scientists at the Centers for Disease Control and Prevention (CDC) have concluded, after careful review of existing evidence, that Zika virus is a cause of microcephaly and other severe fetal brain defects. Microcephaly describes a baby or child with a smaller than normal brain and head. Increasing evidence from a number of recently published studies and a careful evaluation using established scientific criteria supports these conclusions. It does not mean, however, that all women who have Zika virus infection during pregnancy will have babies with problems. CDC’s media statement on this new conclusion can be found here. In other past Zika virus outbreaks, there have been reports of neurologic syndromes, such as Guillain Barre Syndrome, in a small number of patients. Studies are still underway to learn more about health conditions associated with Zika virus and the effects of Zika virus infection during pregnancy.

What special precautions should pregnant women take to prevent Zika virus?
The role of Zika virus infections during pregnancy is being studied. Out of an abundance of caution, the Centers for Disease Control and Prevention (CDC) advises that pregnant women avoid traveling to countries with ongoing Zika virus infections. If pregnant women need to travel to a country with Zika virus, it is recommended they take the following steps to avoid mosquito bites:

  • Choose an EPA?registered insect repellent and use according to the product label. Use the
  • repellent day and night because the mosquito species that transmit Zika virus are daytime biters
  • that will also enter buildings and bite at night
  • Use permethrin?treated clothing
  • Cover exposed skin by wearing long sleeves, pants, and hats
  • Sleep indoors in rooms screened windows or air?conditioning, o or use a bed net if you sleep in
  • an room that is exposed to the outdoors

How is Zika virus spread?
Zika virus is mainly spread in a person to mosquito to person cycle. An infected mosquito bites a person. The person infected by the mosquito will have Zika virus in their blood, especially in the first week of illness. Another mosquito bites that infected person, becomes infected and can then bite another person. People who are infected but who are not sick may still pass the virus on to mosquitoes that bite them. Zika virus can also spread from mother to baby during pregnancy or during the time of birth.

An MMWR from February 26, 2016, reported 6 new cases of sexual transmission of Zika virus investigated by CDC and state public health departments. CDC continues to emphasize that the primary mode of Zika virus transmission is through the bite of an infected mosquito. There is still more to be learned regarding sexual contact as a mode of transmission for Zika virus. Based on what we know now, sexual partners can protect each other by using condoms to prevent spreading sexually transmitted infections. People who have Zika virus infection can protect others by preventing additional mosquito bites. Further guidance will be released as information becomes available.

Current recommendations about the specific timeframes to consider for the prevention of sexual transmission of Zika virus can be found here. Also, guidelines for men and women attempting conception after potential exposure to Zika virus can be found here.

What is the treatment for Zika virus infection?
There is no specific treatment for Zika virus infection. Healthcare providers primarily provide supportive care to relieve symptoms. This may include rest, fluids, and use of over the counter medicine. Infected people should also stay indoors or wear protective clothing and mosquito repellent for the first week after they begin to feel sick. This will help prevent mosquitoes from biting them and potentially spreading the virus to others in the community.

How can a Zika virus infection be prevented?
There is no vaccine to prevent Zika virus infection. Infections can be prevented by avoiding mosquito bites. This includes wearing long sleeved shirts, long pants and socks, using insect repellent or permethrin treated clothing (especially during the daytime when mosquitoes are active), using air conditioning or window/door screens to keep mosquitoes outside, and eliminating standing water from containers in yards (including bird baths, flower pots, buckets) to stop mosquito breeding.

What should I do if I think I have Zika virus infection?
If you have symptoms of Zika virus infection and have been to an affected area in the past two weeks, contact your healthcare provider. Your healthcare provider may test your blood for Zika virus and other similar mosquito borne illnesses.

Where can I get more information?
For additional information, please visit the CDC website: http://www.cdc.gov/zika/.  You may also call your local health department. A directory of local health departments can be found at:

www.vdh.virginia.gov/local-health-districts/. If you have questions about mosquito control programs, you may also contact the see the Virginia Mosquito Control Association: http://www.mosquito-va.org