Thank you very much, Mr. Chair.
Certainly, it's a privilege to be the very first witness, a double privilege. I have a very short deck. I'm going to go through the deck very quickly. I'm going to ask Dr. Matthew Gilmour, who is the head of our laboratory, NML in Winnipeg, to add to that. Those are basically the messages I have.
I'd like to start by conveying three key messages to you. The first key message is that our knowledge is rapidly evolving when it comes to the Zika virus. Many of the recommendations and activities that we're doing currently will likely change as the knowledge increases. The second key message is that the risk to Canadians living in Canada is low at this point in time. The third key message is that based on some of the science we have, we are certainly taking, and I think the globe is taking, a precautionary approach in terms of how we deal with the Zika virus.
Page 2 of the deck talks a bit about the virus, a bit about how it's transmitted. One of the key messages there is that only 20% to 25% of the people who are infected with the virus actually get symptoms. This virus has been around for a long time. It has been around in Africa and Asia since 1947 or 1950, but despite that, we don't know a lot about it, mostly because very few people actually got sick and very few people were hospitalized. It was one of those things that just happened and we didn't even look for it.
The current outbreak of the virus in the Americas is a little bit different, but the vast majority of the genome is the same. It's in a family of viruses, which I'm sure you've heard of, like dengue, yellow fever, and West Nile virus. West Nile virus is the virus that is in Canada, which makes some of the diagnostics a little bit difficult to do.
As I mentioned, there's very limited knowledge. We're learning more and more. You've seen reports of microcephaly and Guillain-Barré syndrome and that knowledge is gradually building. The diagnostics, and Dr. Gilmour will talk to those in a second, are extremely important. A key point here, though, is that there is no treatment. There is no vaccine for this virus and much research is needed.
The next slide is on the risk to Canadians. You've seen in the media that since the huge outbreak in the last several years, over 50 countries worldwide currently have a local circulation or outbreak of this virus and over 30 countries in the Americas at this time.
What's key to us, given that the risk to Canadians, as I mentioned, who live in Canada is very low, is the travelling public. You'll note from the slide that over three million Canadians travel every year to the countries currently affected in the Americas. As of March 7 there have been 20 confirmed cases of Zika in Canada. These are laboratory confirmed and these are all people who have acquired their infection outside the country. The key population that we're worried about is pregnant women and most of the remarks I'll make in the next little while are focused on them.
The next slide is Zika and pregnancy. Brazil, as you're aware, is reporting a serious spike in birth defects known as microcephaly, which is an abnormal head size associated with incomplete brain development. Along with microcephaly, there are other neurodevelopment changes that have been noted as well. This has not been proven yet and that's some of the difficulty.
There is an association of this virus. You've probably seen in the media reports of 5,000 or 6,000 new cases or reported cases of microcephaly. There's some evidence to suggest that those started before the Zika virus was actually in Brazil and there are only a few hundred that have been linked to the Zika virus. I emphasize linked. We will never have proof of this. You can't give a pregnant woman the virus just to see what's going on. They will always be observational studies, but that evidence is gradually building.
We do have evidence of the virus present in fetuses, in placentas. But does it cause the defect or does it just happen to be there? That's what is unknown.
We have special precautions with pregnant women specifically targeted. As you've seen in our travel health notices, we're advising pregnant women who are considering travelling to those countries to reconsider their travel and defer their travel at this time until the outbreak is over. If they must go, they should practice very careful mosquito avoidance techniques.
The other thing that's also new is sexual transmission. Prior to this outbreak, it was exceedingly rare, one or two cases reported globally. You've probably seen in the media a few more cases of sexual transmission. The virus seems to exist in semen. Our knowledge so far is up to about two weeks and there have been a few cases of men who have gone to these countries, become infected with the virus, and given it to women through sexual contact when they come back.
On slide 5 I'm going to talk a bit about our domestic response. Key to us is surveillance. We're monitoring the outbreak, compiling a national picture to find out what's going on, and we're certainly meeting our obligations under international health regulations.
We're a signatory to the International Health Regulations with the WHO. We're not obligated to the IHR to report on all cases of Zika that are acquired outside the country, but we are obligated if anyone acquires Zika inside Canada, or if it's associated with a birth defect.
We've been producing a lot of guidance, such as travel health notices, which I've alluded to. We have a public health notice going to the general public. We have CATMAT, the Committee to Advise on Tropical Medicine and Travel, a group of experts we've put together. They've been in existence for many years. They have produced a series of travel guides and put them on our website.
We also have laboratory testing and recommendations for Zika virus, which Dr. Gilmour will talk about in a second. You're probably aware that there's a 21-day deferral period in place for blood, cell tissue, and organ donations. My colleagues from Canadian Blood Services will speak to that in a minute.
Slide 6 talks about the diagnostic testing support, and I wanted to let you know that we have had the virus in Canada since 2013. It was isolated from a traveller who acquired it in Thailand in 2013. We kept a sample of it in our laboratory, which gave us a jump-start on the diagnostic tests for the virus. The virus was 99% identical.
Matt, do you want to add a few comments about our diagnostic support?