Zika virus disease (Zika) is a disease caused by Zika virus that is spread to people primarily through the bite of an infected Aedes species mosquito. The most common symptoms of Zika are fever, rash, joint pain, and conjunctivitis (red eyes). 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. Once a person has been infected, he or she is likely to be protected from future infections.
Through mosquito bites
Zika virus is transmitted to people primarily through the bite of an infected Aedes species mosquito (A. aegypti and possibly A. albopictus). These are the same mosquitoes that spread dengue and chikungunya viruses.
- These mosquitoes typically lay eggs in and near standing water in things like buckets, bowls, animal dishes, flower pots and vases. They prefer to bite people, and live indoors and outdoors near people.
- Mosquitoes that spread chikungunya, dengue, and Zika are aggressive daytime biters. They can also bite at night.
- Mosquitoes become infected when they feed on a person already infected with the virus. Infected mosquitoes can then spread the virus to other people through bites.
- The Zika virus can also be spread through sexual contact and blood transfusion. In known cases of sexual transmission, men had Zika symptoms and spread the virus to sex partners. Research shows the virus might persist in semen longer than in blood; studies to determine the duration of persistence in semen are not yet completed.
Symptoms, Diagnosis and Treatment
- About 1 in 5 people infected with Zika virus become ill (i.e., develop Zika).
- The most common symptoms of Zika are fever, rash, joint pain, or 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.
- See your healthcare provider if you are pregnant and develop a fever, rash, joint pain, or red eyes within 2 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 symptoms of Zika are similar to those of dengue and chikungunya, diseases spread through the same mosquitoes that transmit Zika.
- See your healthcare provider if you develop the symptoms described above and have visited an area where Zika is found.
- If you have recently traveled, tell your healthcare provider when and where you traveled.
- Your healthcare provider may order specialized blood tests to look for Zika or other similar viruses like dengue or chikungunya.
- There is no vaccine to prevent or specific medicine to treat Zika infections.
- Treat the symptoms:
- Get plenty of rest.
- Drink fluids to prevent dehydration.
- Take medicine such as acetaminophen (Tylenol®) to relieve fever and pain.
- Do not take aspirin and other non-steroidal anti-inflammatory drugs.
- If you are taking medicine for another medical condition, talk to your healthcare 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.
- Zika can also be spread through sexual transmission.
Steps to prevent mosquito bites
When traveling to countries where Zika virus or other viruses spread by mosquitoes are found, take the following steps:
- Wear long-sleeved shirts and long pants.
- Stay in places with air conditioning or that use window and door screens to keep mosquitoes outside.
- Sleep under a mosquito bed net if you are overseas or outside and are not able to protect yourself from mosquito bites.
- Use Environmental Protection Agency (EPA)-registered insect repellents. When used as directed, EPA-registered insect repellents are proven safe and effective, even for pregnant and breast-feeding women.
- Always follow the product label instructions.
- Reapply insect repellent as directed.
- Do not spray repellent on the skin under clothing.
- If you are also using sunscreen, apply sunscreen before applying insect repellent.
- If you have a baby or child:
- Do not use insect repellent on babies younger than 2 months of age.
- Dress your child in clothing that covers arms and legs, or
- Cover crib, stroller, and baby carrier with mosquito netting.
- Do not apply insect repellent onto a child’s hands, eyes, mouth, and cut or irritated skin.
- Adults: Spray insect repellent onto your hands and then apply to a child’s face.
- Treat clothing and gear with permethrin or purchase permethrin-treated items.
- Treated clothing remains protective after multiple washings. See product information to learn how long the protection will last.
- If treating items yourself, follow the product instructions carefully.
- Do NOT use permethrin products directly on skin. They are intended to treat clothing.
Steps to prevent Sexual Transmission
The CDC also recommends that:
- Pregnant women and their male sex partners should discuss the male partner's potential exposures and history of Zika-like illness with the pregnant woman's health care provider.
- Men with a pregnant sex partner who reside in or have traveled to an area of active Zika virus transmission and their pregnant sex partners should consistently and correctly use condoms during sex or abstain from sexual activity for the duration of the pregnancy.
- Couples in which a man resides in or has traveled to an area of active Zika virus transmission who are concerned about sexual transmission of Zika virus may consider using condoms consistently and correctly during sex or abstaining from sexual activity.
Prevent Mosquito Breeding
Although Zika is not present in the US. It is important to still practice source reduction in your backyard. The potential vectors of Zika are backyard breeding mosquitoes that breed primarily in artifical containers.
- At least weekly empty or get rid of cans, buckets, old tires, pots, plant saucers and other containers that hold water.
- Keep gutters clear of debris and standing water.
- Remove standing water around structures and from flat roofs.
- Change water in pet dishes daily.
- Rinse and scrub vases and other indoor water containers weekly.
- Change water in wading pools and bird baths several times a week.
- Maintain backyard pools or hot tubs.
- Cover trash containers.
- Water lawns and gardens carefully so water does not stand for several days.
- Screen rain barrels and openings to water tanks or cisterns.
- Treat front and back door areas of homes with residual insecticides if mosquitoes are abundant nearby.
- If mosquito problems persist, consider pesticide applications for vegetation around the home.