The Cyclospora outbreak has turned deadly, with Michigan health officials reporting that two people have died after becoming infected with the parasite that causes cyclosporiasis, an intestinal illness known for severe diarrhea.

Officials said both individuals had serious underlying health conditions.

According to the Centers for Disease Control and Prevention, more than 18,000 cases have been identified nationwide. Health experts stress that deaths from cyclosporiasis are rare, and most people recover with proper treatment.