Zika Virus

Topic Overview

What is Zika virus?

Zika virus is a type of virus that is spread by mosquitoes. The mosquitoes that carry Zika are most active during the day but can bite at night.

You're more likely to get the virus if you travel to parts of the world where it's more common. This includes parts of South America, Central America, Mexico, the Caribbean, and the Pacific Islands.

Zika infection is usually mild and may not cause symptoms. But it can be more serious for women who are pregnant because it can cause birth defects.

Experts have found that infection with Zika virus can cause Guillain-Barré syndrome (GBS). But only a small number of people who are infected with Zika virus will get GBS.

To learn more

Doctors are quickly learning more about what happens when people are infected with Zika virus. The most current information about Zika virus is available from the Public Health Agency of Canada (PHAC), the U.S. Centers for Disease Control and Prevention (CDC), and the World Health Organization (WHO). If you are planning international travel, you can learn about the risk of Zika in the area you're travelling to. Contact:

  • The PHAC at its Zika virus: Symptoms and treatment website (www.canada.ca/en/public-health/services/diseases/zika-virus.html) to learn more.
  • The U.S. CDC at its website (www.cdc.gov/zika).
  • Your doctor or local health unit.

How is Zika virus spread?

Travellers who have Zika can spread it if they are bitten by a certain type of mosquito and then these mosquitoes bite other people. These mosquitoes are not found in Canada at this time.

A pregnant woman who gets infected with Zika can pass it to her unborn baby.

Zika can be spread through sexual contact even if the person does not have symptoms. But it is most often spread through a bite from an infected mosquito.

What are the symptoms?

Most people infected with Zika don't have any symptoms.

The main symptoms are fever, rash, painful joints, and red eyes. Symptoms are usually mild. They most often start within a week after the bite.

Some people also have a headache and muscle pain.

How is it treated?

There is no treatment for Zika virus. Symptoms usually go away on their own after about a week.

Treating your symptoms may help you feel better.

  • Ask your doctor before you take an over-the-counter pain medicine, such as acetaminophen (Tylenol), ibuprofen (Advil, Motrin), or naproxen (Aleve).
  • Get extra rest.
  • Drink plenty of fluids.

What if you're pregnant or thinking about becoming pregnant?

Experts believe that babies born to women infected with Zika virus are at risk for birth defects, including microcephaly (say "my-kroh-SEF-uh-lee"). Microcephaly means that the baby's head is smaller than normal. It causes problems in how the baby's brain develops.

The Public Health Agency of Canada (PHAC) and U.S. Centers for Disease Control and Prevention (CDC) recommend that pregnant women wait until after they give birth before they travel to areas where there are Zika outbreaks.

Zika can spread through sexual contact even if the person does not have symptoms. If your male partner has been to an area where there is a Zika outbreak, the PHAC and CDC recommend you delay having sex until the baby is born or use condoms every time you have vaginal, anal, and oral sex.

If you are pregnant and have travelled to an area with an outbreak of Zika, talk to your doctor about getting tested for the Zika virus.

Women who are thinking about becoming pregnant and their male partners should talk to their doctor about their risk of travelling to areas where there are Zika outbreaks. Experts recommend that you avoid pregnancy if you or your male partner has been to an area with ongoing Zika transmission.

After returning from the area:

  • A women should wait 2 months before getting pregnant, or 6 months if she or her partner has symptoms of Zika infection.
  • A man should wait 6 months before getting his partner pregnant.

How can you prevent Zika virus?

There is no vaccine to prevent Zika virus. But you can protect yourself from mosquito bites, especially when you travel. Remember that the mosquitoes that spread Zika are active during the day.

  • Wear long pants and long-sleeved shirts.
  • Use insect repellent with DEET or icaridin (Picaridin):
    • You can buy DEET in Canada at strengths up to 30%. It is available in greater strengths in other parts of the world. But using strengths greater than 50% does not significantly increase protection. DEET is not recommended for use on children younger than 6 months. For older children up to age 12 years, use the lowest concentration available (10%).
    • You can buy icaridin (Picaridin) in Canada at strengths up to 20%. Icaridin is not recommended for use on children younger than 6 months.
    • Where the risk of disease is high, PHAC recommends using higher concentrations of repellent and using repellent on children younger than 6 months but only for short periods of time.
  • If you are pregnant or breastfeeding and are concerned about using DEET or icaridin, talk with your doctor. There is no evidence that the use of DEET by pregnant or lactating women poses a health hazard to developing babies or children who are breastfeeding.
  • Spray clothing with DEET or icaridin. Mosquitoes may bite through thin clothing. (Remember that DEET can damage plastic, such as watch crystals, eyeglass frames, and some synthetic fabrics.) Icaridin is less likely to cause skin irritation than DEET and does not damage synthetic fabrics or plastics.
  • Sleep under mosquito netting if you sleep during daylight hours.
  • Use flying-insect spray indoors around sleeping areas.
  • Do not leave puddles or open containers of water near where you are staying. Mosquitoes breed in standing water.
  • Avoid areas where there is an outbreak, especially if you are pregnant.

If you have been to an area where there is a Zika outbreak, use condoms or do not have sex for at least 2 months for women and 6 months for men.

If you do get infected with Zika, protect yourself from mosquito bites, especially during the first week. Men or women should use condoms or not have sex for at least 6 months after symptoms begin. This will help prevent the virus from spreading to other people.


Current as of: August 22, 2019

Author: Healthwise Staff
Medical Review:
Adam Husney MD - Family Medicine
Thomas M. Bailey MD - Family Medicine
Kathleen Romito MD - Family Medicine
Elizabeth T. Russo MD - Internal Medicine
E. Gregory Thompson MD - Internal Medicine
W. David Colby IV MSc, MD, FRCPC - Infectious Disease

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