What is cyclosporiasis, the parasitic illness causing ‘explosive’ diarrhea?

Cyclosporiasis, a parasitic illness causing 'explosive' diarrhea, has surged in Michigan and 18 U.S. states, with Michigan reporting its largest outbreak in history (nearly 1,000 cases) compared to its usual annual 50 cases. Ohio has also seen a sharp rise, with 177 cases as of July 2. The CDC notes it is rarely life-threatening but can have severe effects.