Have you ever performed any live blood cell analysis, or specifically dark field microscopy?
There is no room for doubt that it's rather common for yeast to exist in the blood stream in a very healthy person. The degree of which the fungal forms are able to propegate or infect the host runs along a wide scale, so to simply state that 50% of people don't survive this is a fundamentally flawed statement. I suppose if you mean x number of patients who have greater than x number of yeast cells per 5 grams of venous blood has a statistical fact within a study where 50% of patients survived....well then you might have something.
Just pointing out that there is sufficient proof out there which states the opposite of your opinion here.