Zika virus disease is caused by a virus transmitted primarily by Aedes mosquitoes, which bite during the day.
Zika virus is similar to dengue fever, yellow fever and West Nile virus. Carried by infected Aedes aegypti mosquitos, Zika is largely transmitted through bites, but can also occur through intrauterine infection.
The rash associated with the Zika virus is a combination of flat blotches (macules) and raised tiny reddish bumps (papules). The technical name for the rash is “maculopapular.” It’s often itchy.
Causes
The virus was first identified in the Zika Forest in Uganda in 1947, but outbreaks have since been reported in southeastern and southern Asia, the Pacific Islands and the Americas.
The Zika virus is transmitted primarily through the bite of an infected aedes species mosquito, which can be found throughout the world.
When a mosquito bites a person infected with the Zika virus, the virus enters the mosquito. When the infected mosquito then bites another person, the virus enters that person's bloodstream.
The virus enters your lymph nodes and bloodstream. Your immune system’s reaction to the virus can be expressed in a maculopapular rash.
The virus can also spread to the fetus during pregnancy.
Spread of the virus through sexual contact and blood transfusion have been reported.
Symptoms
As many as 4 out of 5 people infected with the Zika virus have no signs or symptoms. When symptoms do occur, they usually begin two to seven days after a person is bitten by an infected mosquito.
Signs and symptoms of the Zika virus most commonly include:
- Mild fever
- Rash
- Joint or muscle pain
- Headache
- Red eyes (conjunctivitis)
Most people recover fully, with symptoms resolving in about a week.
Diagnosis
Infection with Zika virus may be suspected based on symptoms of persons living in or visiting areas with Zika virus transmission and/or Aedes mosquito vectors.
A diagnosis of Zika virus infection can only be confirmed by laboratory tests of blood or other body fluids, such as urine or semen.
Treatment
There is no special treatment for the Zika virus or for the rash. Recommended treatment is similar to that for other flu-like ailments:
- medication for pain and fever
- rest
- plenty of fluids
- acetaminophen to reduce fever and pain
Prevention
Protecting yourself against mosquito bites is the first line of defense against the Zika virus.
In areas where there’s a risk of Zika, take steps to reduce the mosquito population. This means getting rid of any standing water near the house that could breed mosquitoes, from plant pots to water bottles.
If you live in or are traveling to a region where there’s a risk of Zika:
Wear protective clothing including long sleeves, long pants, socks, and shoes.
Use an effective mosquito repellent that has at least a 10 percent concentration of DEET.
Sleep under a bed net at night and stay in places with window screens.
Risk factors
Factors that put you at greater risk of developing the Zika virus include:
Living or traveling in countries where there have been outbreaks;
Being in tropical and subtropical areas increases your risk of exposure to the virus that causes the Zika virus. Especially high-risk areas include several islands of the Pacific region, a number of countries in Central, South and North America, and islands near West Africa. Because the mosquito that carries the Zika virus is found worldwide, it's likely that outbreaks will continue to spread to new regions.
Having unprotected sex:
The Zika virus can spread to another person through sex. If male sex partners or a couple that includes a male and female partner travel to an area with a Zika risk, the Centers for Disease Control and Prevention (CDC) suggests using condoms or avoiding sex for three months. If female partners travel to an area with a Zika risk, the CDC suggests using condoms or avoiding sex for at least two months. Also, the CDC advises abstinence from sexual activity during pregnancy or condom use during all sexual contact for a pregnant woman or her partner who have traveled to or lived in an area of active Zika virus transmission.