Zika virus

The first cases of Zika virus infection were reported in Africa and Asia in the 1950s. In 2007, the first major outbreak of the virus occurred in Micronesia (Yap Island) in the southwestern Pacific Ocean. Between 2013 and 2015, other significant outbreaks were reported on islands and archipelagos in the Pacific region. In 2015, the virus appeared in Brazil in South America. It then spread to Central America, the Caribbean and Mexico, where cases of local infection were reported. In 2016, local transmission of the Zika virus was identified for the first time in Brownsville, Texas, and in Miami-Dade, in Florida. Transmission was limited. No other cases of infection in the continental United States have been reported since 2018.

To find out where there is a risk of Zika virus transmission, go to the Government of Canada’s list of countries with recent or ongoing risk of Zika virus infection .

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
• 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 neurological complication)
• Birth defects (microcephaly, for example) that can affect the unborn child when a woman is infected with the virus during pregnancy

Currently, there is no vaccine or treatment for Zika virus infection. However, experimental vaccines are being evaluated. Most infected people recover without treatment.

The Zika virus is usually spread through the bite of an infected mosquito. It can also be transmitted sexually during vaginal, anal and oral sex. The virus has been found in the semen of infected men up to several weeks after infection. It has also been found in women’s genital secretions for about 10 days after the onset of the illness. Little is known about how long the virus stays in women’s genital secretions.

Pregnant women can also transmit the virus to their fetuses during pregnancy.

The virus can be transmitted during a blood transfusion, but this is very rare. As a precautionary measure, Héma-Québec has added a new eligibility criterion for blood donors. As of February 7, 2016, people who have travelled outside of the continental United States or in Europe must 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.

Although it is not a reportable disease in Québec, Zika virus infection has been under surveillance since January 2016.

Cases of Zika virus infection confirmed by the Laboratoire de santé publique du Québec are reported to regional public health authorities. Public health authorities contact the infected people to find out:

• Where they were infected (region, country)
• How they got infected (mosquito, sexual transmission, etc.)
• The signs, symptoms and complications

As of March 7, 2019, no cases of Zika virus infection have been reported since the beginning of the year. The cumulative number of cases reported since surveillance began is 118, distributed as follows:

• 88 cases in 2016
• 23 cases in 2017
• 7 cases in 2018

Nearly all of these cases developed after travel to a country where there is local transmission of Zika virus by mosquitos.

According to the Public Health Agency of Canada (PHAC), 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 fetus. Information on these cases is provided on the Government of Canada’s Surveillance of Zika page.

Travellers who visit or plan on visiting countries with recent or ongoing risk of Zika virus infection should take individual measures to prevent mosquito bites. For example, they should:

• Use mosquito repellent at all times during outdoor activities, even during the day
• Wear protective clothing (long-sleeved shirts and long pants)
• Put screens on doors and windows

More examples of measures to prevent mosquito bites are available on the Protecting yourself from mosquito and tick bites page.

These measures protect against mosquito bites that can spread several diseases, including the Zika virus, chikungunya, malaria and dengue.

People who travel to areas where the Zika virus is circulating should also protect themselves properly by using a barrier method during sex (a condom, for example) in order to prevent transmission of the virus. The use of a condom is recommended during vaginal, anal and oral sex with all partners for the duration of the trip. Men should continue wearing a condom up to 3 months after their trip and women should consider using barrier methods to protect their sexual partners for at least 2 months after their return. These recommendations were revised by the Public Health Agency of Canada on January 18, 2019, based on developments in the situation and knowledge about the disease. However, male travellers who have a pregnant partner are still advised to avoid unprotected sex for the duration of the pregnancy.

For health advice for people planning to travel to countries where there is active transmission of the Zika virus, see the Government of Canada’s travel health notices .

Special precautions

Pregnant women

• Pregnant women should postpone all travel to an area or a country with recent or ongoing risk of Zika virus infection by mosquito bite .
• As a precaution, because there is a risk of the virus being transmitted to areas adjacent to where active local transmission of the Zika virus by mosquitos is known, pregnant women are advised to also consider postponing travel to those areas. Pregnant women who cannot postpone their trip should discuss it with their prenatal health-care professional. They should also strictly apply personal measures to prevent mosquito bites. Upon their return, their doctor may recommend a blood test. Depending on the results, special prenatal care could be provided.
• As current knowledge of sexual transmission of the Zika virus is limited,it is recommended that pregnant women use, throughout their pregnancy, a barrier method (condoms, for example) during vaginal, anal or oral sex with any partner who has travelled to a Zika-affected destination.

Women planning on becoming pregnant and their partner

• Pregnant women should postpone all travel to an area or a country with recent or ongoing risk of Zika virus infection by mosquito bite .
• As a precaution, because there is a risk of the virus being transmitted to areas adjacent to where active local transmission is known, pregnant women are advised to also consider postponing travel to those areas.
• Women who travel to a Zika-affected area should use effective contraception throughout their trip. They should also continue using contraception for two months after their return in order to prevent pregnancy.
• Women who wish to be pregnant should also protect themselves if they have sex with a partner who has travelled to a Zika-affected area. Indeed, the presence of Zika has been detected in the semen of infected men several weeks after infection. Women should wait 3 months after their male partner returns from a trip before having unprotected sex, or 2 months if their partner is a woman.

• Zika virus: Symptoms and treatment
  Public Health Agency of Canada
• Travel health notices
  Government of Canada
• Virus Zika  (in French only)
  Institut national de santé publique du Québec (INSPQ)
• Zika virus
  World Health Organization (WHO)