The cyclosporiasis outbreak has expanded to four new states, the U.S. Centers for Disease Control and Prevention reported.

Some US states are facing a large and growing outbreak of diarrhea caused by cyclospora, a microscopic parasite that can contaminate fresh food or water.

CDC confirms 4,173 U.S. Cyclospora cases as it investigates a lettuce-linked outbreak. More than 7,400 additional reports remain under review.

More than 12,000 cases of cyclosporiasis have been reported across 40 states

Investigators believe additional states will help them better construct how cyclosporiasis moved through the nation's food supply.