// Biological

Zika Virus

What is Zika virus disease? Zika virus disease is caused by the Zika virus, a type of flavivirus.

What is Zika virus disease?

context Zika virus disease is caused by the Zika virus, a type of flavivirus. This virus is spread to people primarily through the bite of a mosquito that carries the Zika virus. The Zika virus is related to dengue fever, West Nile, yellow fever, and encephalitis.

How is Zika virus transmitted?

The Zika virus is primarily spread by specific varieties of mosquitos (Aedes aegypti and Aedes albopictus) that live in tropical and sub-tropical regions, including Africa, Asia and the Pacific, South and Central America, the Caribbean, and the southern United States. When an infected mosquito bites a person, the virus is injected into the blood stream along with the mosquito’s saliva. No mosquito-related outbreaks have occurred in or are likely to occur in Canada as the varieties of mosquitos that carry the virus cannot survive in colder climates. Therefore, the risk of being infected while in Canada is currently low. Climate change may increase the domestic risk of mosquito-borne diseases such as Zika, if Aedes populations become established in the future. The virus can also be spread by:

context Sexual transmission through contact with infected semen, vaginal fluid, blood, other body fluids, and sex toys during vaginal, anal, or oral sex without a condom.
context An infected, pregnant woman to her developing baby.
context Cell, blood, tissue, sperm, and organ donations from infected donors.

Who is at risk?

People at greater risk of Zika virus infection include:

context All travellers to regions with active Zika virus outbreaks.
context Sexual partners of infected persons.
context Pregnant women who become infected can pass the Zika virus onto their unborn child.
context Medical patients who receive blood, cells, tissue, sperm, or organs from an infected donor.
context Workers who come into contact with the blood or other body fluids of Zika-infected patients (for example healthcare and laboratory workers).

What are the signs and symptoms of Zika infection?

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: The Zika virus can remain in the body and be transmitted through bodily fluids and tissues for a prolonged period of time after the onset of illness (with or without symptoms). Although rare, Zika virus infection during pregnancy can cause birth defects in babies including incomplete brain development, abnormally small heads (microcephaly), and other malformations that when seen together are called congenital Zika syndrome (CZS). Pregnancy complications including pre-term birth and miscarriage may also occur. Also rare, Zika virus infection has been linked to occurrences of neuropathy (damage to nerves), myelitis (inflammation of the spinal cord), and Guillain-Barré Syndrome (nervous system disorder that causes muscle weakness and possibly paralysis).

context skin rash
context red eyes (conjunctivitis, pink eye)
context mild fever
context weakness
context headaches
context nausea and vomiting
context lack of energy
context sore joints and muscles

How do I know if I have a Zika virus infection?

context 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.

Can Zika virus infections be treated?

context 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, drinking plenty of fluids, and taking medication to reduce pain and fever. 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.

How can Zika virus infection be prevented?

The best way to avoid infection is to avoid travel to Zika-outbreak areas. Consult the Government of Canada’s ‘Travel Advice and Advisories' website to find out if your destination has a risk of Zika virus disease, and visit a travel health clinic at least 6 weeks before you travel. 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. The mosquitoes that carry Zika virus are especially active during daytime and early evening hours. If travelling to a Zika-outbreak area avoid bites from mosquitoes by taking the following precautionary measures: Health Canada also advises travel and sexual activity precautions for Zika virus. All travellers should take precautions by using condoms or by avoiding sexual contact when in countries or areas with a risk of Zika virus. Women who are pregnant should: Women who wish to become pregnant should: Males who have travelled to Zika-outbreak areas should: Speak to your health care provider for more information.

requirement Wear long sleeved shirts that are tucked in, and long pants.
requirement Wear closed-toe shoes or boots (not sandals) and a hat.
requirement Always read the entire label carefully before using insect repellents.
requirement Use insect repellent on any exposed skin. Avoid spraying directly on the face or contact with lips, eyes, open cuts, or irritated skin.
requirement Spray clothing with insect repellent since mosquitoes may bite through thin clothing.
requirement Reapply repellent if biting occurs.
requirement Choose indoor accommodations that are air-conditioned, and that have well-screened doors and windows.
requirement Use mosquito netting (bed net) when sleeping outdoors or in a building that does not have well-screened windows and doors.
elimination Eliminate mosquito breeding sites near the workplace and living quarters, such as containers of standing water and refuse piles.
requirement Discuss potential travel plans with their health care provider, and may choose to postpone or avoid travel to regions with potential Zika risk. Note that the Public Health Agency of Canada continues to recommend that pregnant women avoid travelling to areas with a current Zika virus outbreak.
requirement Consider postponing or avoiding travel to regions with potential Zika virus risk or an active outbreak.
requirement Wait at least 2 months after travel to a Zika-outbreak area or after illness due to a Zika infection before trying to conceive.
requirement Avoid unprotected sex for at least 3 months after travel by using condoms or avoiding sexual contact.
requirement Wait 3 months after travel before trying to conceive (trying to become pregnant with your partner).
requirement Take precautions to not infect a pregnant partner, by avoiding unprotected sex throughout the pregnancy.