That's the world out there, little green apples and infectious disease.
He grinned. It was the sort of grin that Agnes supposed was called infectious but, then, so was measles.
Humanity shares a common ancestry with all living things on Earth. We often share especially close intimacies with the microbial world. In fact, only a small percentage of the cells in the human body...
In times of stress and danger such as come about as the result of an epidemic, many tragic and cruel phases of human nature are brought out, as well as many brave and unselfish ones.