We Asked An Expert How the Zika Virus Affects Canada

There have been four confirmed cases here.

by Manisha Krishnan
Feb 3 2016, 8:43pm

The Zika virus is transmitted through mosquitos. Photo via Flickr user John Tann

By now you've probably seen at least a handful of sensational headlines about the Zika virus, which was recently declared a global emergency by the World Health Organization.

Perhaps, like me, all you've picked up is that it can spread through mosquito bites or sex and it may cause babies to be born with underdeveloped heads.

But is there really cause for the average Canadian to be concerned?

A Zika virus outbreak that originally took place in Brazil in May 2015, is now expected to impact four million people by the end of this year, according to the WHO, which notes the virus is active in about 24 countries in the Americas.

It's being declared an emergency because of how quickly it's spreading and the link to a birth defect called microcephaly. A baby with microcephaly would have a smaller than normal head and depending on which part of their brain was impacted, could suffer from developmental delays, cognitive delays and seizure disorders—impairments that could last a lifetime.

The two have not been definitively linked though there are strong indicators of a relationship between them.

In 80 percent of cases, however, Zika doesn't cause any symptoms.Those that do develop are generally mild—rash, fever, joint pain—and only last a few days. Here are some things Canadians should know:

How many confirmed cases of Zika have affected Canadians?

At least four—two in BC, one in Alberta and one in Quebec. In all of these cases, the virus was contracted by travelling to affected regions such as South and Central America. Due to privacy reasons, not much is known about the infected Canadians, but Horacio Arruda, the director of health for Quebec, told reporters the woman who was infected in that province was not pregnant and is recovering.

Is the Canadian government issuing travel advisories over areas affected by Zika?

Yes. At the end of January, the Public Health Agency of Canada issued an advisory telling Canadians travelling to South and Central America to protect themselves against mosquito bites e.g. wear repellent, dress appropriately and use mosquito netting. Pregnant women or those considering getting pregnant should discuss travel plans with their doctors and "consider postponing travel to areas where the Zika virus is circulating in the Americas." The advisory maintains that risk to Canadians is low.

Is there a concern that the virus could spread in Canada?

No. The virus is transmitted via Aedes mosquitoes, which we don't have here. "Canadians can travel to Zika-virus affected areas, get bitten, get infected, return to Canada, and get bitten by a mosquito," said Issac Bogoch, of Toronto General Hospital, "but the mosquitos here just don't have the right machinery to transmit the virus."

Should everyone who comes back from affected areas get tested?

"Not at all," said Bogoch. There are guidelines for pregnant women coming back from travel—blood tests and ultrasounds that can be used for screening. But a Toronto woman who recently returned home from Brazil says she is considering an abortion because she was refused the blood test due to not showing symptoms. Instead, her health care providers have offered to track the development of her fetus' head with ultrasounds. The woman said she may terminate the pregnancy because "we are just completely unwilling to take the chance."

Can it spread from person to person? What about through sex?

The vast majority of times, the virus is spread through mosquitos, although there is one recent case out of Texas that is confirmed to have spread through intercourse. In that case, the partner of the person who contracted the virus had recently travelled to Venezuela.

"By no means should anyone discount that this could be sexually transmitted," said Bogoch. "If you have symptoms you should obviously wear a condom and get tested. If you come back from a Zika-virus infected area, you should wear a condom for a month."

What is Canada's role in responding to the public health emergency?

According to the Public Health Agency of Canada, the government will coordinate with global agencies like WHO to monitor the virus and share information. The agency's microbiology lab is also equipped to help diagnose the virus. Gregory Taylor, Canada's chief public health officer, told journalists that Canadian and American researchers have paired up to try to develop vaccines for the virus at Laval University.

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