Cyclospora Outbreak Expands in United States

Hawaii reports new cyclospora cases amid a national surge in infections from the foodborne parasite. Federal officials indicate that recalled produce linked to the largest outbreak is no longer available. Recent data from the Centers for Disease Control and Prevention (CDC) shows 18,445 confirmed cyclosporiasis cases since May 1, up from 17,180 cases last week, marking an increase of 1,265 cases. Now, 49 states and the District of Columbia report confirmed cases.

Previously exempt from the national map, Hawaii confirms multiple cyclosporiasis infections, adding to the national tally. Newsweek sought comment from Hawaii’s Department of Health by email.

State Cyclospora Counts

Michigan remains the hardest-hit, with 4,000 to 6,999 cases reported by the CDC. Hawaii joins the CDC map with 1 to 49 confirmed cases. The CDC reports cyclospora in all states except Delaware. Delaware officials note activity in their state, despite CDC’s report showing zero confirmed cases due to sequencing requirements. Specimens from Delaware are currently pending sequencing results at the CDC.

The CDC reassures that iceberg lettuce linked to a multistate outbreak has exited the food supply. Despite the recall, infections continue, suggesting other outbreak sources. As of August 27, over 11,400 illnesses in 20 states have tied to the lettuce outbreak, with 495 hospitalized and two fatalities. Beyond the lettuce outbreak associated with central Mexico, the CDC is examining other cyclospora clusters.

Cyclospora and Its Impact

Cyclospora cayetanensis, the parasite causing cyclosporiasis, is transmitted through contaminated food or water, often fresh produce consumed raw. It does not spread from person to person as the parasite matures in the environment first. In the U.S., most cases occur from May to August, but reports may come later due to delays in diagnosis and reporting.

Common Symptoms of Cyclospora

Signs of cyclosporiasis include prolonged watery diarrhea, stomach cramps, bloating, nausea, loss of appetite, fatigue, weight loss, and increased gas, with possible vomiting or low-grade fever. Symptoms appear one week after exposure, ranging from two days to two weeks. Without treatment, the illness persists for weeks, with symptoms sometimes improving before returning.

Recalled Products

This year’s primary outbreak linked to processed iceberg lettuce from central Mexico was distributed by Taylor Farms de Mexico. The recall was announced on July 17, with federal assurances that the lettuce is no longer available. Despite the absence of positive cyclospora tests in Taylor Farms’ products, federal officials confirm its removal from the market. Hawaii notes the lettuce was not distributed in-state, suggesting a possible link to other outbreaks or unique sources.

Comparing Cyclospora Seasons

This year’s cyclospora outbreak significantly surpasses previous years. Since May 1, the CDC reports 18,445 confirmed cases, along with 990 hospitalizations and two deaths. In the same period in 2025, there were 1,180 confirmed cases nationwide. Experts caution that even current figures likely underestimate the true outbreak scope, due to unreported or undiagnosed cases. The 2026 season’s end is expected to draw further case increases as additional reports are processed and investigations continue.