I think part of the difficulty relates to the fact that viruses are the troublemakers, and Dr. Khan alluded to this. The troublemakers tend to be RNA viruses, that's their genetic material that comes from animals. RNA viruses are very good at mutating. What we see with this virus, which is a cousin of SARS 1, and bears a lot of similarity to SARS 1, is that it behaves differently in important ways. Being 80% similar can still translate into some very important differences, but some very important similarities.
What we tend to see, what we almost always see with infectious diseases as they emerge, is we find out about hot spots first. Typically we have this sense of the virus being more virulent than it ultimately turns out to be. That's certainly been the case with some outbreaks. What we saw with this virus, also initially, was it looked a lot like SARS based on the information we knew from China. I've acknowledged publicly I think my biggest mistake was thinking it really was looking like SARS in China. We did some forecasting on how the Chinese seemed to be doing in controlling it, and we accurately forecasted that it would be done in Wuhan by early March. That was right, but the difficulty was we didn't see Iran coming. Once you saw this in Iran, you knew the game was over, and this was going to disseminate around the world.
They're all the same, but they're all different. When you look at some of the key parameters, as we talk about, with these diseases, which let you sort of predict how things are going to play out, some important numbers include the reproduction number of the disease, the number of new cases per old case. This virus turns out to be a real trickster, in that it's got what's called an overdistributed reproduction number, where many cases are dead ends but some individual cases make 40 secondary cases. You see that play out again and again, whether it's in nursing homes, on cruise ships or in restaurants. As you know, there's the single individual in Korea who infected 40 secondary cases and sparked a massive outbreak in the city of Daegu.
That makes it difficult. It also provides a potential vulnerability for the virus in terms of control, because once you get rid of those large gatherings that make super-spreading events difficult, the virus becomes much less transmissible. The initial case fatality that we saw coming out of China—that's deaths per case—was listed as 2.4%. Of course, deaths go up slowly with this thing, because people die in the ICU. The China case fatality I think at this point is 5% or 6%. We're at 7% in Canada.
As for what we know now, we've been helped a lot in this regard by data from Spain from last week, from a national seroprevalence study, where they were able to find both the recognized and the unrecognized infections. About 5% of the country of Spain has had this, with 27,000 deaths. Now we're able to go from a case fatality in Spain, which is deaths per recognized case, down to an infection fatality rate, which in Spain we now are pretty sure is about 1.2%, based on seroprevalence data.
The fact that Spain is at 5% prevalence 30,000 deaths in, with an infection fatality rate of 1%, makes me very concerned about some of Dr. Schabas's remarks in terms of moving towards herd immunity. We think that we'd hit herd immunity at 60% to 70% of Canadians infected. Seventy per cent of Canadians infected is 28 million people, and 1% of that is 280,000 Canadians dead. I would note that the failure to have mass mortality in Canada to date relates to the public health response.
I would also note that we can do this because we've shown around the country that we can control this disease without just letting it rip and pushing for herd immunity, as they're doing in Sweden. We've seen competence in British Columbia. We've seen tremendous competence in Atlantic Canada and on the Prairies. We can do this. We just need to get the job done.
Throwing your hands up and saying that we're going to follow Stockholm, Sweden, which is currently leading Europe in per capita mortality, is not the way to go, in my opinion.
