There is sickness in the spiritual world, but there are no infectious germ diseases.
In fact, all the Sickness there is in the Spiritual world is due to the violation of natural and spiritual laws.
These violations become less frequent as the spirit-life evolves and becomes more enlightened and developed and may be said to disappear entirely in the second Spiritual Zone.
In the first spiritual zone, however, sickness is comparatively frequent due in part to the fact that the spirit-life is still imperfectly developed and inclined to evil, and in part to the nearness of earthbound spirit-lives and of the spirit-lives of the physical material worlds.
This sickness that is in the spiritual world varies from that of mere restlessness and unhappiness to actual spiritual suffering, according to the frequency with which laws have been violated and the spirit-life's general attitude toward these laws and the purpose of life.
The spirit-lives of the spiritual world soon learn how best to live—through seeing and experiencing—that restlessness, unhappiness and suffering, which are the result of living otherwise, and through constantly being urged on—by something within them—to the joy of a higher life.
Benjamin F. Woodcox, Fragments of Spiritual Knowledge Pertaining to the Spiritual World, Woodcox & Fanner, Battle Creek, Michigan, 1923