Michigan is the hardest hit, now reporting over 1,200 cases

Cases of cyclosporiasis, which causes explosive diarrhea and other food poisoning symptoms, have topped 1,000. See which states have the most.

Cases have risen quickly as officials are working to identify a common source.

An unprecedented 700-plus cases have been reported in Michigan alone

In neighboring Ohio, cases have reportedly reached over 500.

A "large and growing outbreak"