Zika virus

The first cases of Zika virus infection were reported in Africa and Asia in the 1950s. In 2015, the virus appeared in Brazil, in South America. It then spread to Central America, the Caribbean and Mexico. In 2016, a Zika virus outbreak was reported for the first time in Brownsville, Texas, and in Miami-Dade, in Florida. This outbreak caused few cases. No other outbreak has been reported since 2018 in the continental United States.

To find out if a country is at risk of Zika virus transmission, go to the page Travel advice and advisories by destination on Health Canada’s website and select the country. The information on diseases spread by insects, like the Zika virus, are under the “Health” tab.

The Zika virus is primarily spread through the bite of an infected mosquito. The mosquitos that most often transmit the virus are found in many countries but are not found in Québec or in other parts of Canada. Our climate conditions are not conducive to their development.

The incubation period for the Zika virus is 3 to 14 days. Most people infected by the virus (75 to 80%) do not have symptoms or have only mild symptoms. When symptoms appear, they are generally mild and last 2 to 7 days. The main symptoms are:

• Low-grade fever (38.5°C or lower)
• Muscle or joint pain, with possible swelling of the joints of the hands and feet
• Red eyes (conjunctivitis)
• Skin rashes with small bumps on the face and body
• Weakness, lack of energy and headaches

In rare cases, the Zika virus can cause more serious illnesses such as:

• Guillain-Barré syndrome (a problem associated with the nervous system)
• Premature birth, miscarriage or abnormalities in newborns (ex., the baby’s head is smaller than normal) when a woman is infected with the virus during pregnancy

Currently, there is no vaccine or treatment for Zika virus infection. Most infected people recover without treatment.

The Zika virus is usually spread through the bite of an infected mosquito.

It can also be transmitted during vaginal, anal and oral sex, or when sharing sex toys up to several weeks after infection. A person who is pregnant can also transmit the virus to their fœtuses during pregnancy.

The virus can be transmitted during a blood transfusion, but this is very rare. As a precautionary measure, Héma-Québec requires people who have travelled outside of the continental United States or in Europe wait 21 days after their return to Canada to donate blood. This measure is intended to prevent the risks associated with the transmission of the Zika virus and similar viruses, such as the dengue fever and chikungunya viruses.

Public health has been monitoring the Zika virus since 2016 and the virus was added to the list of reportable diseases in October 2019.

In 2016, a large number of cases were reported (88) during a significant Zika outbreak in Central and South America. Since then, the number of cases has varied between 0 and 23 per year.

Nearly all of these cases developed after a mosquito bite during a trip outside Canada.

According to the Public Health Agency of Canada, the risk of contracting the Zika virus is low for Canadians. It is mostly limited to people who travel or who live in Zika-affected areas. In Canada, cases of Zika virus infection have been confirmed  in people who were infected outside the country, by sexual transmission or by transmission from a mother to her fœtus. Information on these cases is provided on the page Surveillance of Zika  on the Government of Canada’s website.