The United States is facing its largest cyclosporiasis outbreak in years. As of July 9, 2026, CDC has counted 843 domestically acquired cases in 31 states, as well as another 343 cases linked to travel outside the country, reported by 32 states. Combined, the number of confirmed infections now exceeds 1,100, and officials expect the number to continue rising.
The parasite responsible, Cyclospora cayetanensis, causes intestinal illness that includes watery diarrhea, cramps, nausea, fatigue, and loss of appetite. Household cases range in age from 5 to 88 years, with the average age being 44 years, and 59% of patients are female. According to available data, out of 843 domestic patients, 86 required hospitalisation, although no deaths have been reported.
Investigators are struggling to catch the culprit
Unlike many foodborne outbreaks, this one has resisted easy tracing. Symptoms usually emerge a week or more after exposure, so patients often cannot remember what they ate during the relevant window. CDC also believes There is a lag of about six weeks between when someone falls ill and when a case is officially reported, meaning current figures likely underestimate the true scale of the outbreak.
As of July 7, health officials found no evidence that the rising number of cases represented a single, multistate outbreak linked to a contaminated product. Instead, several small groups, including a rapidly growing group in Michigan, appear to have evolved together without any definite common source.
Historically, Cyclospora has been detected in imported fresh produce. Basil, cilantro, spinach, berries and lettuce have been repeatedly implicated in past outbreaks as items consumed raw, particularly during the warmer months when demand for fresh produce increases.
Challenges of diagnosis and how to protect yourself
standard diarrhea test panel Remember the parasite again and again. Clinicians should request modified acid-fast staining or PCR testing to detect this, especially in patients with persistent, unexplained watery diarrhea.
Trimethoprim-sulfamethoxazole remains the preferred treatment, although options for patients with sulfa allergy are less well established, and untreated disease can drag on for weeks with the possibility of relapse even after apparent recovery.
For prevention, health officials recommend washing produce thoroughly under running water, cutting off bruised parts before eating, washing hands before and after handling raw fruits and vegetables, and avoiding accidental ingestion of water from pools, lakes or untreated sources. No recalls have been issued as investigators continue to search for answers.
