Cyclospora Infections Reach Record Levels in 2026
The Centers for Disease Control and Prevention announced on Tuesday that the U.S. has seen over 2,500 additional cases of cyclospora infections, marking 2026 as the most severe year for this parasitic illness on record.
Since May 1, there have been 4,173 confirmed cases in 41 states, plus 767 infections linked to international travel. The CDC is also looking into more than 7,400 unconfirmed cases. Thankfully, there have not been any reported deaths, though 308 individuals have needed hospitalization.
The previous high was in 2019, with 4,703 cases. Since 2016, the CDC reported an average of around 2,800 cases annually.
Health officials are still trying to figure out the causes of this surge in cyclospora cases, a parasite spread through contaminated food and water. They suspect there are multiple sources but have identified one outbreak responsible for at least 1,644 cases across Michigan, Ohio, West Virginia, Indiana, and Kentucky, linked to shredded iceberg lettuce produced by Taylor Farms in central Mexico.
Experts believe the actual infection numbers may be even higher. Many individuals with cyclosporiasis may not seek testing, and because there’s often a delay in state reporting to the CDC, the counts at the state level frequently surpass those federally. The New York Times contacted state health departments, and they reported a collective total exceeding 11,000 infections.
On Tuesday, Michigan reported 6,148 cases—far more than any other state, with an 85 percent increase compared to the previous week. Typically, Michigan sees about 50 cases annually.
Other states are also experiencing unusual spikes. North Carolina reported an 83 percent increase, while Indiana’s cases rose by 150 percent within the same timeframe.
Last Friday, Taylor Farms initiated a recall of various packaged products containing iceberg lettuce sold in 27 states. However, the company didn’t specify how customers could identify the contaminated items. Federal health experts have warned that other food products may also be involved.
If that recalled lettuce is indeed a primary source of infections in the U.S., cases should start to decline within a week or two following the recall, said Keith R. Schneider, a food safety expert at the University of Florida. Symptoms of cyclosporiasis can take up to two weeks to appear.
A spokesperson from Michigan’s Department of Health noted that it’s premature to say if cases are beginning to decrease.
The FDA is examining several other clusters of cyclosporiasis cases nationwide. Kyle Diamantis, the agency’s acting commissioner, shared this information during a briefing with reporters.
While this year’s surge in cases is significant, it might partly be due to increased awareness of the outbreak, suggested Craig Hedberg, a public health expert. When outbreaks are reported, more people tend to seek medical help, which can drive up testing.
Additionally, doctors may be more inclined to request cyclospora tests for patients, explained Melvin Kramer, an epidemiologist. Not all standard stool tests include cyclospora, making it necessary for doctors to specifically ask for it.
Availability of cyclospora tests has also improved compared to past outbreaks, which might be contributing to the increased case numbers, Dr. Hedberg noted. However, he acknowledged it’s challenging to determine how much these factors are impacting the rise. Future research could look into this, but likely won’t occur during the ongoing investigation, especially with state and local health departments facing budget cuts and staffing issues.
