Maxis Fixing SimCity Traffic Issues, Lack of Persistence a Design Decision

So, here's a question. Say a sim is sick due to his neighbor being sick. Say he ends up going to work, then finding a new home (since there is no persistence) will he then spread the germ to that other part of down? Doesn't this sort of defeat that part of the simulation of how a virus can spread? This may be a moot point, but it really plays down on the level of realism I was hoping to expect from the Simcity franchise.