FDA declares cyclospora outbreak over but origin of 13,000 ‘diarrhea lettuce’ cases is still unknown

Michigan was the hardest hit state, recording the most reported cases and the two U.S. deaths tied to the outbreak - (Getty)

Federal health authorities have declared the largest cyclospora food poisoning outbreak in U.S. history over as questions remain about how the parasite that causes it ended up in our food supply.

Nearly 13,000 cases were tied to the multistate outbreak, representing the bulk of an unprecedented surge in the parasitic diarrheal illness this year.