1892, disease of birds and mammals caused by coccidia, the name of a family of parasitic insects, the scale-insect; their name is Modern Latin, from Greek *kokkidion, diminutive of kokkis, diminutive of kokkos "berry" (see cocco-). Also see -osis.
word-forming element meaning "berry, seed," or something shaped like them, from Latinized form of Greek kokkos "a grain, a seed," especially "kermes-berry, gall of the kermes oak" (actually an insect), which yields scarlet dye, a word of unknown origin, perhaps from a non-Greek source.
word-forming element expressing state or condition, in medical terminology denoting "a state of disease," from Latin -osis and directly from Greek -osis, formed from the aorist of verbs ending in -o. It corresponds to Latin -atio.
<a href="https://www.etymonline.com/word/coccidiosis">Etymology of coccidiosis by etymonline</a>
Harper, D. (n.d.). Etymology of coccidiosis. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/coccidiosis