CDC investigates parasite that’s caused cases of ‘explosive’ diarrhea in 18 US states | US healthcare
The U.S. Centers for Disease Prevention is working to find the source of a parasitic disease that causes “explosive,” watery diarrhea, with more than 400 cases of the disease reported in 18 states.
The cyclospora parasite spreads through raw produce and water contaminated with human feces and causes the intestinal disease cyclosporiasis, whose symptoms include cramps, nausea, fatigue, loss of appetite, low-grade fever and vomiting. The most commonly reported symptom is “watery diarrhea with frequent and sometimes violent bowel movements.” CDC.
Between May 1 and June 16, 145 cases of cyclosporiasis were reported in 17 states. CDC in question. 20 of these cases resulted in hospitalization.
Cyclosporiasis is generally not life-threatening and no deaths were reported in the recent outbreak.
New York, Texas, Illinois and Michigan were the hardest hit. Other states with reported cases include Alaska, Colorado, Connecticut, Florida, Georgia, Louisiana, Massachusetts, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia and Wisconsin.
Outside of the CDC’s counting dates, health officials in Michigan are investigating an unusually high number of cases as part of a “large and growing outbreak.” In the state, where approximately 50 cases of cyclosporiasis are usually detected annually, more than 300 cases have been reported since Friday, June 22. according to the health department.
And since May 1, there have been 107 cases in New York. According to the New York state health department, 500 to 700 cases are typically recorded annually statewide. Health officials in New York City reported that cases there roughly doubled from January to June compared to the same period in 2025, according to the New York Times.
The CDC said it is working with the U.S. Food and Drug Administration (FDA) and local officials to investigate clusters of cases in several states. These people became ill after eating in the United States and did not report any travel in the two weeks before they became ill.
The CDC said there is no direct evidence of a single, multi-state outbreak connecting all the cases. Therefore, researchers were trying to identify various potential disease clusters and disease sources across multiple states.
In the United States, the disease is seasonal, with cases generally peaking between May and August. During the spring and summer months, people consume lots of fresh produce, such as basil, cilantro, spinach and berries, which have often been linked to past epidemics.
The CDC said the latest cases are concerning at this time because of the unusually high numbers and as yet unidentified sources.
The CDC said it can usually take two days to two weeks for symptoms to develop after contracting the parasite, and not everyone experiences symptoms.
In more serious cases, the infection is usually treated with antibiotics. However, most people with healthy immune systems recover from cyclosporiasis on their own within days or weeks.
The CDC advises people to wash all fresh produce thoroughly before eating and to also wash hands and kitchen surfaces thoroughly. The CDC said people should contact their healthcare provider if they have symptoms of cyclosporiasis, and if they test positive, they should report it to their local health department. Those who are sick should drink plenty of water and other fluids to prevent dehydration.
The disease is not usually transmitted from person to person.
