Michigan's Cyclospora hospitalization count rose again this week, a week after state health officials told shoppers they could put lettuce back in their grocery carts.
The Michigan Department of Health and Human Services reported 13,909 cases on August 13, an increase of roughly 11 percent from the 12,485 counted a week earlier. Hospitalizations reached 314, up 35 from the 279 counted as of August 6. The death toll remains at two. For scale, Michigan typically records around 50 cases of cyclosporiasis per year.
Those two figures pull in different directions, and reconciling them is the practical question for households. State officials say new case reports and diarrhea-related emergency department visits are declining, and most of the newly logged cases reflect illnesses that began weeks ago and are only now being cleared from laboratory backlogs. The hospitalization increase, however, represents people whose illness became severe enough to require inpatient care, which is a harder number to explain away as a reporting artifact.
Two Official Counts That No Longer Match
A reader comparing headlines this week will find figures that appear to contradict each other, and the explanation is not an error.
The CDC reported 13,895 laboratory-confirmed cases of domestically acquired cyclosporiasis across 47 states, the District of Columbia, and Puerto Rico, counted from May 1 through August 10. Michigan alone reported 13,909 as of August 13. One state's total now exceeds the entire national laboratory-confirmed tally.
Both numbers are correct because they measure different things. The CDC counts laboratory-confirmed cases meeting its formal reporting criteria, and its surveillance page notes that states may report higher counts because they include cases that do not meet those criteria. The agency also says it is aware of at least 10,455 additional cases that are not laboratory-confirmed or require further investigation, and that many of those continue to be reported by Michigan. That single line accounts for most of the gap. The federal figure updates weekly on Tuesdays; Michigan updates on Thursdays.
For context on scale, the CDC reported 1,180 cases nationally between May 1 and August 31 of 2025. Nationally this season it has counted 740 hospitalizations and two deaths among domestically acquired cases, with a median patient age of 45.
The Reason Officials Cleared Lettuce
The recall that anchored this outbreak is closed, which allowed the guidance to change on August 6.
Taylor Farms recalled iceberg lettuce sourced from central Mexico on July 17, covering product sold at retail and served in restaurants, including Taco Bell locations and Marketside-brand products at select Walmart stores. The CDC and FDA said on August 5 that the FDA remains confident all iceberg lettuce related to this outbreak is off the market, and the best-by dates on the recalled products have since passed. Michigan health officials then lifted the precautionary recommendation to avoid bagged salad mixes and are now encouraging residents to continue eating fresh produce while taking ordinary food safety steps.
The reason cases keep appearing despite that is incubation and lag rather than ongoing exposure. Symptoms typically begin about a week after infection, and the CDC estimates a six-week lag between when someone becomes ill and when the case is reported to the agency. MedicalDaily previously reported that Michigan attributed a large single-day addition to delayed laboratory reporting rather than new infections.
Washing produce reduces risk but does not eliminate it for this parasite, which is why source removal mattered more than any consumer step.
The Symptom Pattern That Sends People to the Hospital
The rise in hospitalizations is the part of this update that should change household behavior, because it points to a specific failure mode.
Cyclosporiasis produces frequent watery diarrhea, loss of appetite, bloating, nausea, and fatigue, sometimes with body aches, headache, or vomiting. The distinguishing feature is that without treatment, the illness can last for weeks and may come and go, appearing to resolve before returning. People who assume they had a passing stomach bug can cycle through that pattern for a month.
The complication driving hospital admissions is dehydration, particularly in older adults and people with underlying conditions. Michigan officials said both deaths involved people with significant underlying health conditions.
The parasite does not spread from person to person, so household members do not need to isolate from one another. What they do need is testing, and this is where many cases are missed. Routine stool panels frequently do not detect Cyclospora. Testing must be ordered specifically, which means patients should mention the outbreak by name when seeking care. An untested person with lingering symptoms is still at risk because treatment with the appropriate antibiotic shortens an illness that would otherwise persist.
Anyone with diarrhea lasting more than a few days, signs of dehydration such as dizziness, reduced urination or confusion, or symptoms that resolve and return should contact a clinician rather than waiting it out.
The Questions Investigators Have Not Closed
Several things remain unresolved despite the reassuring tone of the produce guidance.
The CDC says it is investigating multiple clusters of Cyclospora cases nationally, and only the iceberg lettuce investigation has an identified source. The others have not been publicly linked to a food, and whether they are connected to the lettuce outbreak has not been established.
Michigan's case count will continue rising for reasons unrelated to current risk, and readers should expect that. The more meaningful indicators to watch are the weekly change in hospitalizations and whether the FDA names sources for the remaining clusters. Michigan posts updated figures on Thursdays by 11 a.m. Eastern: The CDC refreshes on Tuesdays.
The bottom line is narrow. Officials say the implicated lettuce has been removed and that fresh produce is safe to buy. The people who still need to act are those who have been sick for weeks and never had a Cyclospora-specific test ordered.
Key Questions Answered
What is new in this update? Michigan reported 13,909 cases and 314 hospitalizations as of August 13, an increase of 35 hospitalizations in one week, while new case reports and emergency visits declined.
Why is Michigan's count higher than the CDC's national count? The two use different criteria. The CDC counts only laboratory-confirmed cases that meet its formal reporting definition and separately notes more than 10,000 additional cases awaiting confirmation, many of which are from Michigan.
Is lettuce safe to buy now? Michigan health officials lifted the precautionary advisory on August 6 and are encouraging residents to continue eating fresh produce. The FDA has said all iceberg lettuce tied to this outbreak is off the market.
Why do case numbers keep rising, then? Reported cases reflect when laboratory results reach the state, not when people got sick. The CDC estimates a six-week lag between illness and reporting.
What symptoms should people watch for? Watery diarrhea that recurs rather than resolves, with cramping, nausea, bloating, loss of appetite, and fatigue. Symptoms usually begin about a week after exposure.
Why might a stool test come back negative? Routine stool panels frequently miss Cyclospora. Testing must be ordered specifically, so patients should mention the outbreak when seeking care.
Does it spread between people? No. It spreads through contaminated food or water, not person-to-person.
