HARTFORD–A national increase in incidents of the intestinal illness Cyclosporiasis has struck in Connecticut, where health officials report that cases have almost doubled so far this year over last.

The Connecticut Department of Public Health (DPH) today announced that 35 cases of the disease have been confirmed in the state as of today, compared with 19 cases reported at the same last year.

People become infected by consuming food or water that contains the Cyclospora parasite, the DPH said. The most common symptom is frequent, watery diarrhea, though some individuals may experience no symptoms at all, the department said.

The department has not identified any specific food source of the disease and urges residents to follow safe food-handling, including carefully washing produce, to reduce the risk of catching it. 

“Connecticut’s surveillance system is doing exactly what it should: identifying cases, tracking exposures, and helping us stay ahead of this illness,” said Commissioner Manisha Juthani, M.D. “We want to reassure residents that cyclosporiasis is treatable and we have not identified a Connecticut-specific source. At the same time, we encourage everyone, especially those at higher risk, to take a few simple precautions with fresh produce this summer. Washing your produce thoroughly, buying whole heads of lettuce instead of pre-washed bagged varieties, and cooking herbs and leafy greens when possible are steps that go a long way.”

Illness typically begins within one week of exposure but can range from two days to more than two weeks. Most healthy people will recover from cyclosporiasis without treatment although their illness may be prolonged. Cyclosporiasis is treatable with antibiotics, rest, and adequate hydration.

State and federal agencies offer conflicting information on the extent of the disease across the country. The Connecticut health department says the cyclosporiasis has been reported in 17 states, with the most significant cluster occurring in Southeast Michigan. The Michigan Department of Health and Human Services reports 2,460 cases.

The U.S. Centers for Disease Control and Prevention (CDC) reported 843 domestic cases, but from 31 states. The agency says state counts are sometimes higher because they include probable and confirmed cases, with “initial case counts” that may not have been reported to the CDC yet.

The CDC reports an additional 343 cases that apparently were contracted from food and drink consumed while traveling in other countries.

Five of Connecticut’s 35 cases also were linked to international travel, the DPH said. Officials are still investigating where the remaining cases developed.

No specific produce grower, supplier, or food item has been identified as the source of that outbreak to date. Historically, United States outbreaks of cyclosporiasis have been linked to fresh produce, including bagged salad mixes, fresh cilantro, fresh basil, raspberries, snow peas, and green onions, the DPH said.

Cyclosporiasis is a reportable condition in Connecticut; healthcare providers and clinical laboratories are required by law to report cases to DPH. DPH conducts statewide surveillance and interviews all reported cases to identify any exposure patterns or common food sources. Connecticut’s first cyclosporiasis case of 2026 was reported on May 2. While cyclosporiasis is not usually life-threatening, dehydration from frequent diarrhea can cause serious complications, particularly for young children, older adults, and individuals with weakened immune systems, such as those undergoing chemotherapy or organ transplant recipients, DPH said. Anyone experiencing sudden, ongoing watery diarrhea is encouraged to contact their healthcare provider promptly.

Safe Produce Practices to Reduce Your Risk

DPH recommends the following food safety steps, particularly for higher-risk individuals:

• Wash all fresh produce under clean running water before eating, even if you plan to peel it.
• Buy whole heads of lettuce rather than pre-washed, bagged salad mixes. Remove and discard the outer two to three layers of leaves and wash inner leaves under running water.
• Wash cilantro, basil, and green onions thoroughly under running water, separating leaves. These items are safest when cooked.
• Cook produce when possible. Heating food to 158°F (70°C) or higher kills Cyclospora.

General Food Safety Reminders

• Wash hands with soap and water before and after handling or preparing food.
• Scrub firm fruits and vegetables, such as melons and cucumbers, with a clean produce brush.
• Wash and sanitize cutting boards, surfaces, and utensils before and after handling food.
• Refrigerate cut, peeled, or cooked fruits and vegetables as soon as possible.

If You Become Ill

People experiencing sudden and persistent diarrhea, particularly watery or explosive diarrhea, are encouraged to contact their healthcare provider. Cyclosporiasis is treated with antibiotics along with rest and adequate fluids to maintain hydration. 

More information is available on the CDC website at www.cdc.gov/cyclosporiasis.