Mystery parasite leaves Americans battling ‘explosive diarrhea’ as CDC investigates

July 2, 2026 - 22:04

A mysterious parasitic outbreak is spreading across the United States, leaving dozens of people suffering from violent diarrhea and stomach cramps. The Centers for Disease Control and Prevention has confirmed 145 cases of cyclosporiasis across 17 states, with 20 patients requiring hospitalization so far. The illness, caused by the microscopic parasite Cyclospora cayetanensis, triggers explosive diarrhea that can last for weeks if untreated. Health officials are racing to identify the source of the contamination, which typically spikes during the warmer months.

The CDC notes that most infections occur between May and August, often tied to imported fresh produce like cilantro, raspberries, or salad mixes. However, the current outbreak has no clear link to a specific food item yet. Symptoms usually appear about a week after consuming contaminated food or water, and include watery diarrhea, loss of appetite, weight loss, and fatigue. While the parasite does not spread directly from person to person, it can survive in soil or water for long periods.

Doctors warn that cyclosporiasis is often misdiagnosed as a stomach bug because its symptoms mimic other infections. The standard treatment involves a specific antibiotic, but many patients recover without medical help. Still, the CDC urges anyone with persistent diarrhea to see a doctor and mention possible parasite exposure. As the investigation continues, public health experts advise washing all produce thoroughly and avoiding raw fruits or vegetables from unknown sources. The outbreak serves as a reminder that foodborne illnesses remain a serious threat, even in countries with advanced sanitation systems.