The Lillith Virus, named for Adam's first wife, was first found in an ice core sample from Antarctica. It's spread through the human population was rapid.
A primitive sibling of EDS, Electromagnetic Sensitivity is a rare affliction that grew to prevalence in the late Petroleum Era, and persists into the Cosmic Era. What was formerly a psychosomatic form of hypochondria is a recognized, and paradoxically, officially discredited disease.
Of creatures great and small
The Omen Plague has other names. It is known as The Star Plague and even The Mundane Plague. It is still with us today, now known by the common name of the Shaking Death. To set the stage, the stars were aligned in all the wrong signs. Everyone new something bad was going to happen. When winter set in hard and early, they thought that was it. They were wrong.
A Cloak of Shadows that causes mushrooms to grow in its own shadow. A crouching theif might find himself in a ring of poisonous toadstools, an interesting thing for a sentry to find after the thief has left hiding place.