The Centers for Disease Control and Prevention said they have received reports of 843 confirmed domestic cases since May 1, and they are aware of more than 1,500 additional cases awaiting further analysis and confirmation.

The illness is caused by the microscopic parasite cyclospora, which can lead to weeks of gastrointestinal illness, including a hallmark symptom of explosive diarrhea.

Health officials say dozens of states are investigating cases, with 10 cases reported in Arizona and more than 1,500 cases and 44 hospitalizations reported in Michigan.

Dr. Natasha Bhuyan of One Medical explained that this infection is typically seen in the summer due to increased consumption of imported fruits and vegetables. Unlike many foodborne illnesses linked to meat, cyclospora is most often associated with fresh produce like raspberries, blackberries, basil, and leafy greens. "People look back and say, 'I didn't eat anything unusual yesterday or the day before,' but it might have come from fruit they ate even weeks ago," Bhuyan said.