That's an excellent question.
Whenever one of these events happens, we do a risk assessment, so we look at the organism, look at transmission models, look at the outcomes, look at if there are ways to prevent it, if there is a vaccine. We look at all of those things and do a risk assessment and come up with what the risk is to Canadians. Granted, the definition of “low” versus “very low” is relatively subjective with that one, but in this case we don't have the virus in Canada. The mosquito vector doesn't exist in Canada. The only way they could infect, which we've just learned, is through sexual transmission. That's relatively new. Initially we didn't know that. Initially we didn't know about blood, because that is relatively new as well, so the estimate was that the risk to Canadians in Canada is very low.
Those risk assessments are updated on a ongoing basis, so we're looking at constantly updating. If new information comes in, research results come in, our scientists look at it again and look at our assessment and say, “Do we need to change that? Has the risk changed or not?” This is exactly the same thing we did throughout the Ebola outbreak, which is why we saw different measures for Ebola. When our assessment came it was still low, but we were watching this and acting.
It's an excellent question that gets into the core of what the agency does on an ongoing basis—constantly doing risk assessments and constantly monitoring that.