Zika Virus

Context

The first cases of Zika virus disease have been reported in Africa and Asia since the 1950s. In 2007, there was an outbreak of the virus in Micronesia (Yap Island) in the southwestern Pacific Ocean. Between 2013 and 2015, other important outbreaks were reported in islands and archipelagos of the Pacific region. In 2015, the virus appeared in South America and Central America, where cases of infection have been reported locally. Since then, the Zika virus has continued to spread in the Americas. The Centers for Disease Control and Prevention (CDC) have reported local transmission of Zika virus:

  • in southern Florida since August 2016
  • in the town of Browsville, Texas since November 28, 2016

For a list of all countries affected by the Zika virus, go to the World Health Organization (WHO)’s website.

Description

The Zika virus is primarily spread through the bite of an infected mosquito. Mosquitos that most often transmit the virus is widespread, but it is not found in Québec. Climatic conditions in Québec are not conducive to its development. During the 2016 surveillance period in Canada, the 2 main types of mosquitoes that can transmit the Zika virus were identified in southern Ontario. However, neither carried the virus. Officials in Ontario believe the mosquitoes came from the United States. They have not been identified elsewhere in Canada.

The incubation period for the Zika virus is 3 to 12 days. Most people infected by the virus (75% to 80%) show little or no symptoms at all. When symptoms appear, they are generally mild and last 2 to 7 days. The main symptoms of the virus 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 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

Treatment

Currently, there is no vaccine or treatment for the Zika virus. However, experimental vaccines are under review. Most infected people recover without treatment.

Transmission

The Zika virus is usually 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 sperm 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 virus. 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 it’s rare. As a precautionary measure, Héma-Québec has added new eligibility criteria for blood donors. As of February 7, 2016, people who have travelled outside of the continental United States and 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 Zika and similar viruses, such as dengue and chikungunya.

Surveillance of the Zika Virus in Québec

Although it is not a reportable disease in Québec, it is presently under enhanced surveillance.

Cases of the Zika virus disease confirmed by the Laboratoire de santé publique du Québec are reported to regional public health officials. Public health officials communicate with infected people to know:

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

As of February 1st, 2017, 91 cases of people infected with the Zika virus have been confirmed in Québec. Nearly all of these cases were acquired after a travel to a country where there is local transmission of Zika virus by mosquitos.

Situation in Canada

According to the Public Health Agency of Canada (PHAC), the risk of contracting Zika virus disease is very low for Canadians. It is mostly limited to people who travel or who live in areas where the virus circulates. In Canada, cases of Zika virus disease have been confirmed in people who were infected outside the country, by sexual transmission or by transmission from a mother to her fetus.

Traveller Information

Travellers who visit or plan on visiting places affected by the Zika virus should take individual measures to prevent mosquito bites. For example, they should:

  • Use mosquito repellent at all times during your outdoor activities, especially 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 6 months after their trip, and women should consider using barrier methods to protect their sexual partners for at least 8 weeks after their return. These recommendations may be revised according to the evolution of the situation and of knowledge about the disease.

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 planned trips to countries where the Zika virus is circulating, including the affected areas of South Florida and Texas. As a precaution, because there is a risk of the virus being transmitted to areas adjacent to where local transmission is known, pregnant women are advised to consider postponing travel all other parts of Florida and Texas. 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

  • Women planning on becoming pregnant should postpone all planned trips to countries where the Zika virus is circulating, including the affected areas of South Florida and Texas. As a precaution, because there is a risk of the virus being transmitted to areas adjacent to where local transmission is known, pregnant women are advised to consider postponing travel to other parts of Florida ans Texas.
  • 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 sperm of infected men several weeks after infection. Women should wait 6 months after their male partner returns from a trip before having unprotected sex, or 2 months if their partner is a woman.

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Last update: February 1, 2017 2:17 PM

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