Cyclosporiasis Cases Surge Across 34 States as Officials Probe Lettuce

A widespread outbreak of cyclosporiasis, an intestinal illness caused by the parasite *Cyclospora*, has reached 34 states, with federal and state health officials actively investigating potential links to fresh produce. While the Centers for Disease Control and Prevention (CDC) has confirmed 1,645 cases since May 1, the agency is analyzing more than 5,100 additional reports to determine if they are domestically acquired.

The surge is part of a national trend, with health authorities warning that the true number of infections is likely higher than current lab-confirmed figures. Some data suggests 2026 could become the nation’s worst year for reported cases, potentially exceeding the 2019 record of approximately 4,700 illnesses.

Investigation Focuses on Lettuce and Salad Greens

The source of the current outbreak remains under investigation, but attention has increasingly turned toward lettuce. In Michigan, where more than 3,300 cases have been reported, health officials stated that early information from over 1,000 patient interviews points to lettuce or salad greens as a common factor.

“Early information has shown lettuce as a common product that regularly comes up during the investigation,” said Natasha Bagdasarian, the Michigan health department’s chief medical executive.

As a precautionary measure, the restaurant chain Taco Bell announced it has voluntarily and temporarily removed limited ingredients at select locations. Federal officials, including the Food and Drug Administration (FDA), are conducting traceback investigations on multiple produce items and locations reported by patients. Gwen Biggerstaff, deputy director of the CDC’s Division of Foodborne, Waterborne, and Environmental Diseases, emphasized that the illness does not spread through casual contact, stating: “The source of this outbreak is what we eat or drink — not casual contact with someone who’s sick.”

For more on this story, see Cyclosporiasis Cases Hit 5,000 Across 31 States With Midwest Surge.

Symptoms and Clinical Challenges

Cyclosporiasis is characterized by watery diarrhea, often described as “explosive,” along with loss of appetite, weight loss, stomach cramps, bloating, increased gas, nausea, and fatigue. Symptoms typically appear anywhere from two days to two weeks after consuming contaminated food or water, with an average onset of about one week. This delay in symptoms creates significant challenges for public health investigators attempting to trace the source of infection, as patients often struggle to recall specific meals consumed during the exposure window. The illness is generally treated with antibiotics, though many individuals may recover without medical intervention. However, the CDC cautions that symptoms can be persistent, sometimes lasting for a month or longer, and can occasionally resolve only to return later.

This follows our earlier report, Cyclosporiasis Cases Surge Across US With Michigan as Outbreak Epicenter.

Risk Factors and Prevention

Because the parasite is microscopic and cannot be detected by taste or smell, health officials urge the public to follow strict food safety protocols. To reduce the risk of infection, health authorities recommend:

Read also: Cyclosporiasis Outbreak Hits 32 States With Thousands of Confirmed Cases.

• Thorough washing: Rinse all fresh produce under running water, even if items are labeled prewashed.
• Preparation: For lettuce, consider buying whole heads and discarding the outer layers.

While the illness is rarely life-threatening, it can cause severe dehydration and electrolyte loss. Dr. Bruce Vanderhoff, director of the Ohio Department of Health, noted that the condition is a “serious illness that can cause dehydration and require people to seek emergency medical care, and it should be taken seriously.” Individuals experiencing prolonged watery diarrhea, fatigue, or loss of appetite are encouraged to seek medical attention and request specific laboratory testing for the parasite.

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