Your model doesn't account for racial profiling of the bio-weapon.

That could skew any results derived mathematically... a lot!

Until a cross-section of victims is developed which is based on race, this important piece of information is lacking.

Also, bio-weapons will mutate quicker than wild strains, presumably... as in a family of six who are all infected, showed different strains detected individually.

My opinion... is a weapon being developed to use on us got used on them, and somehow, the tables were turned... perhaps by our "remarkable" American researchers!