Cyclospora Infections Hit Record Highs in the U.S. for 2026

The year 2026 has seen a significant rise in cyclospora infections, surpassing all previous records in the United States. Over 30 states have reported outbreaks, with current figures exceeding the previous high of approximately 4,700 cases recorded in 2019. While cyclospora infections are usually not life-threatening, antibiotics often treat them. The exact source of the outbreak remains unknown, although infection patterns show variations across different states. At least four states—Michigan, Ohio, Kentucky, and West Virginia—are believed to have linked cases.

Michigan Cases Point to Lettuce

Michigan stands out with over 3,300 reported cases, prompting officials to suspect lettuce as a potential source. Natasha Bagdasarian, Michigan’s chief medical executive, noted that interviews with over 1,000 patients frequently referenced lettuce as a common factor. Based on this, Michigan health officials recommend buying whole lettuce heads, removing the outer layers, and thoroughly washing the inner leaves. Bagged lettuce and pre-mixed salad kits are advised against.

As a precaution, Taco Bell temporarily removed select ingredients from specific restaurants and continues to work closely with health authorities. Despite queries about the source, federal health officials did not confirm investigating Taco Bell or similar entities. Donald Prater, Acting Deputy Commissioner for Food at the FDA, confirmed ongoing traceback investigations into multiple produce items reported by patients.

Understanding Cyclospora

The cyclospora parasite is a microscopic organism linked with watery diarrhea characterized by frequent bowel movements. According to the Centers for Disease Control and Prevention (CDC), infections often occur in late spring and summer. The parasite thrives in warm conditions, spreading usually through feces, and contaminates fruits and vegetables via irrigation water.

Compared to other foodborne diseases like salmonella and E. coli, cyclospora is less common. Historically, due to testing limitations, many cases were underreported. A notable increase in reported cases occurred in 2018 and 2019, attributed to climate change and improved detection techniques.

Previous Outbreak Records and Current Investigations

The U.S. had its worst year in 2019, with 4,700 infections reported. However, 2026 has surpassed this record, as indicated by CDC alerts. Since May 1, over 1,645 confirmed domestic cases have been identified, with more than 5,100 requiring further evaluation. These reports involve 34 states, with no deaths reported so far.

The total number of infections is likely underestimated; many people with milder symptoms do not seek medical help. Symptoms of cyclospora can take weeks to manifest, and it remains uncertain when and where exposures occurred. According to Gwen Biggerstaff from the CDC, numbers are expected to rise through August.

The CDC’s alert outlined investigation efforts concerning the outbreak in four states. Specific state data include more than 3,300 cases in Michigan, over 1,100 in northwest Ohio, more than 400 in New York City, and over 200 in Illinois. Not all of these cases share a common source. For example, in Illinois, many infected individuals reported traveling abroad, suggesting possible overseas infections. Michigan officials, however, suspect a domestic outbreak within their state.

Associated Press writer Dee-Ann Durbin also contributed to this report. The AP Health and Science Department is supported by the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation, with AP maintaining sole responsibility for content.