Definition

A Zika infection is caused by a virus. It is often passed from an infected mosquito. It may cause flu-like problems in some, but does not cause problems in most people. It can cause serious birth defects in babies who are still in the womb.

Causes

A specific type of mosquito can pick up Zika when it bites a person with the infection. The mosquito can then pass the virus to the next person it bites. Most Zika infections pass this way.

Zika can also pass from person to person. It may pass:

• During sex with a man with Zika who may or may not have any signs of being sick
• To an unborn baby if the mother had Zika during or just before pregnancy

Risk Factors

The risk is greater in those who have spent time in a high-risk place without mosquito protection. Zika happens in:

• South America, mostly Brazil; Colombia, Bolivia, Ecuador, French Guiana, Guyana, Paraguay, Suriname, and Venezuela
• Mexico and Central America, mostly Guatemala, El Salvador; Honduras, and Panama
• The Caribbean, mostly Barbados, Dominican Republic, Guadeloupe, Haiti, Martinique, Puerto Rico, and Saint Martin
• Southeast Asia and the Pacific Islands
• Africa

Symptoms

Symptoms do not always happen. If they do, they may show up a few days after the bite. These problems may last a few days to a week:

• Fever
• Rash
• Eye redness and irritation
• Headache
• Joint and muscle pain

Zika infection in pregnant women may cause these problems for the baby:

• Microcephaly—a small head due to poor growth of the brain
• Brain defects
• Eye problems
• Hearing loss
• Slow growth
• Muscle stiffness and spasms
• Seizures
• Joints that are not normal

Diagnosis

The doctor will ask about your risk of exposure to Zika from travel or sex.

A blood test is needed to confirm Zika. It will look for the virus or signs that the body has fought the virus. It may be given to pregnant women who:

• Are at risk and have symptoms of Zika
• Have not had symptoms of Zika but who are at risk
• May have been exposed and have had abnormal ultrasounds during pregnancy

A woman with a positive test will need to see a maternal-fetal or infectious disease specialist.

Treatment

Medicine cannot treat Zika. Symptoms should pass on their own in a week. Rest and fluids can help.

Acetaminophen may be given to ease fever or pain. Nonsteroidal anti-inflammatory drugs (NSAIDs) and aspirin can cause problems in women with dengue infection.

If a mosquito bites a person who is infected, it can pass the infection to someone else. Steps will be needed to avoid mosquito bites for about a week.

Family Planning

The Zika virus may stay in the body or in sperm for a short time even after symptoms go away. To lower the risk of passing the virus to a new fetus:

• Women who have been infected or suspect an infection should wait at least 8 weeks before trying to get pregnant.
• Men who have been infected or had possible exposure to Zika should wait at least 3 months before trying to have a child with their partner.

Prevention

Pregnant women who live in areas without Zika should not travel to places where it is spreading. Those in areas with Zika should take steps to not get bit by mosquitoes. They should also use a condom during sex or not have sex with a male partner who has lived in or traveled to an area with Zika.