The point is to slow it down, not actually know which ritual failed. We aren't worried about how you or I really get it, it doesn't matter if it actually was c

The point is to slow it down, not actually know which ritual failed. We aren't worried about how you or I really get it, it doesn't matter if it actually was carried by a supernatural deity following certain people around or if someone has a death note that uses 5g radio waves to target individuals in the phone book. We only know that crowds and ignoring hygeine carry it faster and we just need time to treat it. If you are personally in an at-risk group and are avoiding it like the plague that it is, none of the policies have real answers you. We are operating on probabilities, not absolutes.