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.
In Québec, the risk of contracting the Zika virus is low. It is mainly limited to people who travel or live in regions where the virus is circulating.
The Zika virus has been the subject of vigilance by Québec public health since January 2016. It was added to the list of notifiable diseases in October 2019.
In 2016, 88 cases were reported in people residing in Québec, while a major outbreak of Zika virus infection was underway in South and Central America. Since then, the number of cases has varied between 0 and 23 per year but has remained very low since 2017.
Nearly all these cases were infected following a mosquito bite during a trip outside Canada, since the vector is not present in Québec.
Transmission
The Zika virus is mainly transmitted by the bite of an infected mosquito, generally the Aedes aegypti mosquito. This mosquito is most active during the day and early evening. The presence of this mosquito is largely restricted to tropical and subtropical regions. This mosquito is therefore not present in Québec or elsewhere in Canada. Our climatic conditions are not conducive to its development.
An infected person can transmit the infection through vaginal, anal and oral sex, or by sharing sex toys, for 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.
These measures protect against mosquito bites, which can transmit several diseases, such as Zika virus infection, chikungunya, malaria, dengue fever, etc.
In addition to measures to protect themselves from mosquito bites, people traveling to areas where there is active transmission of the Zika virus should also adequately protect themselves during sexual intercourse by using a barrier method (e.g. a condom) to prevent transmission of the virus. Condom use is recommended during vaginal, anal and oral sex, or when sharing sex toys with any partner, for the duration of the trip. Males should continue to use a condom for three months after returning from travel, and females for at least two months.
For recommended health advisories for people planning to travel to countries with active Zika virus transmission, please consult the Government of Canada's travel health advisories.
Specific precautions for people who are pregnant or planning to become pregnant, and their partners.
People who are pregnant or planning a pregnancy should postpone any planned trip to a country where there are recent and ongoing cases of Zika virus infection.
Pregnant people who are unable to postpone their trip should discuss this with the healthcare professional monitoring their pregnancy. They should also rigorously apply the recommended personal protection measures against mosquito bites.
Pregnant people are advised to use a barrier method (e.g. a condom) during vaginal, anal or oral sex, or when sharing sex toys with any partner who has been back from a Zika virus transmission zone for less than three months.
People traveling to an area of active Zika virus transmission should use effective contraception for the duration of their trip. They should also continue contraception for up to two months after their return to avoid becoming pregnant.
People planning a pregnancy should wait three months after their male partner's return from travel before having unprotected sex, or two months if the partner is female.
Symptoms
The incubation period for the Zika virus is 3 to 14 days. The majority of people infected with this virus (75-80%) show few or no symptoms. When symptoms are present, they are generally mild and last from 2 to 7 days. The main symptoms are:
fever;
muscle or joint pain, with possible swelling of hand and foot joints;
red eyes (conjunctivitis);
reddening of the skin, with small bumps on the face and body;
weakness, lack of energy;
headaches.
In rare cases, the Zika virus can cause more serious complications such as:
Guillain-Barré syndrome (a problem associated with the nervous system);
premature birth, miscarriage or abnormalities in the newborn (e.g. baby's head smaller than normal) when a woman is infected with the virus during pregnancy.
Treatment
There is currently no treatment or vaccine against the Zika virus.
Severely ill people may need to be hospitalized. They then receive care to stabilize and improve their state of health.