Zika Virus

Zika virus disease is caused by the Zika virus. This virus is spread to people primarily through the bite of a mosquito that carries the Zika virus.

The specific variety of mosquito that carries Zika virus is not found in Canada, but it is found in many warm weather countries world-wide. No mosquito-related outbreaks have occurred in or are likely to occur in Canada as the varieties of mosquito that can pass the virus cannot survive in colder climates. Therefore, the risk of being infected while in Canada is low.

People who travel to countries with Zika virus outbreaks are at risk. Women who are pregnant or planning to become pregnant are advised to avoid this travel. Pregnant women that become infected can pass the Zika virus onto their unborn child.

Zika virus can also spread by sexual transmission through semen from infected men, or possibly through a blood transfusion (not confirmed) received from infected travellers returning from affected countries.

There is a risk of Zika infection in workplaces for those that come into contact with the blood or other body fluids of Zika-infected patients (for example: healthcare and laboratory workers).

The Zika virus is primarily spread by specific varieties of mosquitos that live in warm weather countries. As of August 2016, there are active outbreaks of Zika virus in many countries in South America, Central America, the Caribbean, and in the southern US.

The virus can also be spread by:

• Sexual transmission through semen from infected men.
• An infected, pregnant woman to her developing baby.
• Cell, blood and tissue donations from infected donors.

Many people who are infected with Zika virus will not have any symptoms. In general, only 1 in 4 people with a Zika virus infection show symptoms. People who show symptoms may have a rash, red eyes, mild fever, weakness, headaches, lack of energy, or sore joints and muscles.

Zika symptoms may appear from 3 to 12 days after infection. Symptoms, if they appear, are usually mild and may last 2 to 7 days.

Although rare, Zika virus infection during pregnancy can cause birth defects in babies including incomplete brain development and abnormally small heads (microcephaly). Also rare, Zika virus infection has been linked to occurrences of Guillain-Barré Syndrome, which is a nervous system disorder that causes muscle weakness and possibly paralysis.

Your health care provider can determine whether you should be tested for Zika virus infection based on your symptoms, places and dates of travel, and activities. Pregnant travelers returning from Zika outbreak countries should discuss concerns with their health care provider.

Currently there is no treatment or vaccine for the Zika virus infection. Treatment is provided to relieve symptoms of the infection, which can include rest and drinking plenty of fluids. Do not take acetylsalicylic acid (ASA) until a possible infection from Dengue virus has been excluded since Dengue is also common in mosquitoes in Zika outbreak areas.

The best way to avoid infection is to avoid travel to Zika-outbreak areas.

If travelling to a Zika-outbreak area avoid bites from mosquitoes by taking the following precautionary measures:

• Wear long sleeved shirts that are tucked in, and long pants.
• Wear shoes or boots (not sandals) and a hat.
• Always read the entire label carefully before using insect repellents.
• Use insect repellent on any exposed skin. Avoid spraying directly on the face or contact with lips, eyes, open cuts, or irritated skin.
• Spray clothing with insect repellent since mosquitoes may bite through thin clothing.
• Reapply repellent if biting occurs.
• Choose indoor accommodations that are air-conditioned, and that have well-screened doors and windows.

Employers that require workers to travel to Zika-outbreak areas should ensure that the workers know about the risk of Zika virus disease and how to prevent mosquito bites.

Health Canada currently advises to avoid travel to Zika-outbreak areas if you are pregnant or are planning on becoming pregnant. If travel is unavoidable, follow strict mosquito bite prevention measures. In addition, women who are pregnant should take precautions with potentially infected partners by using condoms or by avoiding sex. Women who wish to become pregnant should wait at least 2 months after travel to a Zika-outbreak area.

Males who have travelled to Zika-outbreak areas and who have sexual partners that are pregnant should avoid unprotected sex throughout the pregnancy and for at least 6 months after travel by using condoms. Males are cautioned to wait 6 months after travel before trying to conceive (trying to become pregnant with your partner).

Speak to your health care provider for more information.

More information is available from:

• Zika Virus - Health Canada
• Zika Virus - U.S. Centers for Disease Control and Prevention (CDC)
• Zika Virus - World Health Organization (WHO)