Information updated in January 2017
Zika virus causes infection in humans and is transmitted by mosquitoes found in South and Central America, the Caribbean, Mexico and in southern parts of the United States, as well as many tropical and sub-tropical areas around the world. The virus was originally only found in Africa and Asia, and first reported in the Western Hemisphere in 2015. Outbreaks of Zika virus infection have now been reported in many countries in the Americas, including the United States, and it is likely that transmission will continue to occur in countries where the mosquitoes are found.
The infection is usually mild and lasts for a week or less. People usually don't get sick enough to seek medical care, and they very rarely die of Zika. However, Zika virus infection during pregnancy is of particular concern as the infection may affect the baby and result in birth defects. There is also a link between Zika and Guillain Barré syndrome – a rare condition where the body's immune system attacks the nervous system causing weakness or paralysis of the muscles. Although Zika is not a new virus, our knowledge about it continues to advance.
This disease is particularly relevant to Canadian women of child-bearing age and their sexual partners who travel to countries with Zika transmission.
See the Top Five Facts about Zika Virus
For recent updates, including travel health notices, visit the Public Health Agency of Canada website.
How Zika virus spreads
Zika is spread mainly through the bite of infected Aedes mosquitoes, the same mosquitoes that spread dengue and chikungunya viruses. These particular mosquitoes are not generally found in Canada due to our cold winters. Studies on the ability of other mosquitoes to carry the virus continue.
The virus can be spread from a pregnant mother to her baby during pregnancy or around the time of birth. Transmission can also occur through blood transfusion. However, persons in Canada will not be allowed to donate blood for 21 days after returning from travel to a risk area. Zika virus can be transmitted sexually.
Symptoms
Approximately 80 per cent of people with Zika virus infection may not be aware that they have been infected. If symptoms occur, these may include fever, rash, joint pain and conjunctivitis (red eyes).
Who is at risk
Anyone who lives in or travels to areas where Zika virus is found and has not already been infected can get it from mosquito bites. The virus has spread to many countries in the Americas where the Aedes mosquito is present. There have also been outbreaks in tropical Africa, Southeast Asia and the Pacific Islands.
Because there is a link to birth defects, such as microcephaly, in babies, becoming infected with Zika is of particular concern to women who are pregnant, those who are planning to become pregnant and their sexual partners.
See the pregnancy poster from Public Health Agency of Canada for details.
Testing
The recommendations for testing may change as the situation evolves.
Testing may be considered for individuals with a history of travel to an area where Zika is found AND one or both of the following criteria:
- Is pregnant;
- Presents with a clinical illness compatible with Zika virus infection.
Countries and Territories with Zika Virus Transmission
Review a list of countries with active Zika virus transmission (U.S. Centers for Disease Control and Prevention).
Information for Travellers
Refer to Public Health Agency of Canada's website for various travel health fact sheets.
Insect bite precautions are explained in detail in the Travel Health and Safety - Insect Bite Prevention section on Government of Canada's website.
If you become ill after having travelled and see your health care provider, remember to tell them that you have travelled.
See the Public Health Agency of Canada's Travel Health Notices
Resources for Health Care Providers
Remember:
- Zika is primarily a risk for travellers. Refer to the Zika Virus – Counselling Travellers fact sheet from Public Health Agency of Canada to assist in providing pre-travel advice.
- Ask your patients about their travel history.
Prevention, Treatment, Diagnosis and Laboratory Testing
- Canadian recommendations on the prevention and treatment of Zika virus (Committee to Advise on Tropical Medicine and Travel)
- Canadian recommendations for diagnosis and laboratory testing of Zika virus infection
- Saskatchewan Disease Control Laboratory (SDCL) update on Zika testing
Currently all laboratory specimens collected in Saskatchewan for testing of Zika virus infection are sent to the National Microbiology Laboratory (NML) in Winnipeg.
All laboratory specimens must be accompanied with the necessary information on the accompanying viral zoonoses requisition form which can be downloaded from the NML's Guide to Services.
Clinical Management
Additional guidance on clinical management of pregnant women and women of reproductive age with possible Zika virus exposure and infants with possible congenital Zika virus infection is available at U.S. Centers for Disease Control and Prevention. Please refer to the Canadian Pediatric Society for additional information.