The Centers for Disease Control and Prevention (CDC) reported 10,468 laboratory-confirmed cases of cyclosporiasis in the United States since May 1, according to its weekly update on Aug. 4. That total represents an increase of more than 3,700 confirmed infections since the agency's July 28 report.
Scope Of The Outbreak
Health departments in 47 states have recorded cases, up from 45 the previous week. The CDC also noted at least 12,255 additional suspected cases that have been reported but not yet confirmed by laboratory testing. To date, the agency says there have been 517 hospitalizations and two deaths.
Michigan Cluster And State-Federal Differences
Federal investigators say they are probing multiple, separate outbreaks. The largest cluster is centered in Michigan. State officials reported 11,508 probable cases and the first two deaths attributed to this outbreak as of Aug. 4 — numbers higher than the CDC's federal count because many state-reported cases are still pending laboratory confirmation and formal submission to the CDC.
Product Traceback And Recall
Federal traceback and testing tied the largest identified cluster to iceberg lettuce produced by Taylor Farms in central Mexico. Taylor Farms initiated a recall of that lettuce on July 17. Confirmed illnesses linked to the recalled lettuce have been reported in nine states: Illinois, Indiana, Kansas, Kentucky, Michigan, Ohio, Oklahoma, Pennsylvania and West Virginia.
Where Cases Have Been Reported
Only three states — Delaware, Hawaii and Montana — had not reported cases in this series at the time of the update. Michigan and Ohio remain among the most affected states, and Washington, D.C., has reported a small number of illnesses.
Symptoms, Risks And Treatment
Cyclosporiasis is caused by the parasite Cyclospora cayetanensis and typically spreads through contaminated food or water. The most common symptom is frequent, watery and sometimes "explosive" diarrhea. Other symptoms can include vomiting, loss of appetite, bloating or gas, stomach cramps, extreme fatigue, fever and nausea.
Most healthy people recover without hospitalization, but the infection can be more severe in people with weakened immune systems or underlying health conditions. Standard treatment for confirmed cyclosporiasis is the antibiotic combination trimethoprim-sulfamethoxazole (TMP-SMX); patients should consult a healthcare provider for diagnosis and care.
Why Tracing Cyclosporiasis Is Difficult
Public health experts say tracking cyclosporiasis is challenging for several reasons: the incubation period can be long (often days to weeks), stool samples are difficult to obtain and test, and the parasite lacks the straightforward genetic markers used to link outbreaks of bacteria such as E. coli or listeria. Because of testing, verification and reporting processes, the CDC notes there is often about a six-week lag between illness onset and the case appearing in federal data.
Ongoing Investigation
The CDC and the Food and Drug Administration (FDA) continue to investigate multiple clusters. While the Taylor Farms iceberg lettuce has been linked to the largest identified cluster, investigators have not yet identified a single common source for all reported cases.
What You Can Do: Wash fresh produce thoroughly, follow recalls and food-safety guidance, seek medical care if you have severe or persistent diarrhea, and tell your clinician about recent produce consumption so appropriate testing and treatment can be considered.
