Death due to honeybees mutated with Box Jellyfish venom.

"the venom causes cells to become porous enough to allow potassium leakage, causing hyperkalemia which can lead to cardiovascular collapse and death as quickly as within two to five minutes"

http://en.wikipedia.org/wiki/Chironex_fleckeri

For each malady you bring up, the genome can be hardened against. Humanity has enough time to iterate ;)