Well, the sickness spread slowly, despite my efforts at intentional contagion, so I'm guessing germ theory doesn't hold in the VS universe.

Luckily, I only had to "sacrifice" three of my tribe before I received the birth I was hoping for. Once that happened I rushed back to heal the remaining sickies and gently carried them in their weakend state to the garden for some rejuvenation time. I swear they must wonder at the capriciousness of the gods.