Graft-versus-host disease (GVHD) is a common side effect of an allogeneic bone marrow transplant. An allogeneic transplant uses blood cells from a family member, unrelated donor or cord blood unit.
Nearly all vertebrate animals host one or more species of the protozoan parasites that produce the infection referred to as coccidiiasis or coccidiosis. Thousands of coccidian species of herbivorous, omnivorous, and carnivorous animals have been described, and many more exist that remain unnamed.
Other causes include: 1  A fall against a hard surface in the seated position, such as a fall from a horse. 2  A direct blow to the coccyx, such as in contact sports.  Straining or dislocating the coccyx. This can happen due to poor posture while driving, or repetitive injury from sports such as rowing or cycling.