# Nationwide Parasite Outbreak Nears 7,000 Cases as Health Officials Point to Contaminated Lettuce
A fast-moving outbreak of a gastrointestinal parasite has sickened or is suspected of sickening nearly 7,000 people across the United States, federal health officials announced this week, with Michigan emerging as the epicenter of an illness that produces weeks of debilitating diarrhea.
The Centers for Disease Control and Prevention said in a health alert that it has formally confirmed 1,645 domestic cases of cyclosporiasis nationwide, while an additional 5,100 cases remain under investigation. ,In a health alert, the CDC reported it had confirmed 1,645 people nationwide have been sickened by cyclosporiasis. An additional 5,100 cases are under investigation., Combined, the confirmed and suspected cases push the national total toward the 7,000 mark.
At least 34 states have reported infections tied to the outbreak, though health officials caution that the federal case count trails behind what individual states are seeing on the ground because each case must go through a confirmation process before it’s added to the CDC’s tally. ,At least 34 states are reporting cases. The national tally lags behind what states are reporting as the agency must confirm each case.,
## Michigan Bears the Brunt
No state has been hit harder than Michigan, where health officials have independently confirmed 3,309 cases — accounting for the majority of the nationwide total. ,The bulk of the cases are in Michigan, which has confirmed 3,309 cases on its own., State data shows ,as of July 9, 2026, 44 reported cases indicated they had been hospitalized, in Michigan alone.
Nationally, the CDC reports that ,141 people have been hospitalized since cases were first reported in May, and no deaths have been reported.,
New York City has also seen a significant cluster of illness, with ,403 cases reported in the city, 374 of them recorded between May and July 10, according to the city’s health department.,
Federal investigators believe several of the outbreaks may be linked. The CDC suspects that at least 400 cases spread across Kentucky, Michigan, Ohio and West Virginia are connected to a single source, though that source has not yet been pinpointed.
## Lettuce and Salad Greens Under Scrutiny
Investigators in Michigan say they’ve made progress narrowing down a likely culprit. After conducting more than 1,000 interviews with people who tested positive for the parasite, state health officials say lettuce and salad greens have emerged as a probable source of contamination.
However, no specific supplier, distributor or retail chain has been publicly named. Dr. Natasha Bagdasarian, Michigan’s chief medical executive, said the scope of the outbreak suggests the contamination likely originated further up the supply chain rather than at any single restaurant or store. ,”We know that contamination usually occurs where the produce was grown or processed, and because distributors supply the same produce to multiple types of establishments,” she said, “it’s unlikely for there to be one single place as the exposure for all of our cases.”,
That assessment lines up with the national picture. ,Nationally, no single product, restaurant, grocer or distributor has been implicated as the source of the illnesses, and there have been no recalls issued.,
Still, at least one major chain has taken precautionary action. ,On Tuesday, Taco Bell Corp said in a statement that it had “voluntarily and temporarily removed limited ingredients at select restaurants as a precautionary measure,” though it noted that public health officials have not confirmed a link to the restaurant chain., The Food and Drug Administration confirmed last week that it has opened its own investigation into the outbreak’s origins.
## What Is Cyclosporiasis?
Cyclosporiasis is caused by Cyclospora cayetanensis, a microscopic, single-celled parasite that spreads when human waste contaminates water used to irrigate or process produce, or through unsanitary food handling practices. ,Previous outbreaks have involved raspberries, bagged lettuce or salads, cilantro, basil, green onions and snow peas.,
Once the parasite attaches to leafy greens or produce, it’s notoriously difficult to remove. ,Once the parasites latch on, they’re hard to wash away, and there’s no evidence that soaking food or dousing it with vinegar or commercial vegetable washes is enough to get rid of them — they need to be scrubbed off or cut off as much as possible.,
Symptoms typically don’t appear immediately. ,If people eat food contaminated with cyclospora, it takes up to two weeks for people to get sick, and the illness can begin with flu-like symptoms, such as fatigue, body aches and nausea., The defining symptom, however, is severe gastrointestinal distress. ,The hallmark symptom of cyclosporiasis is severe, watery diarrhea that’s sometimes uncontrollable.,
Doctors typically treat the infection with the antibiotic Bactrim, though patients who don’t seek treatment can suffer for an extended period. ,Cyclosporiasis is most commonly treated with Bactrim, an antibiotic, and left untreated, symptoms can linger for weeks., Anyone battling the illness is urged to stay well-hydrated to offset fluid loss from diarrhea.
## What Residents Should Watch For
While Michigan, New York and several Midwestern and Northeastern states have reported the highest case counts, health officials note that cyclosporiasis has surfaced in more than half the country this summer, and cases tend to spike seasonally between May and August. North Texans who develop persistent watery diarrhea, especially after eating fresh salad greens or lettuce, are advised to contact a healthcare provider for testing, particularly if symptoms include dehydration or last more than a few days.
Until the FDA traceback investigation identifies a specific grower, processor or distributor, consumers nationwide — including in North Texas — are being urged to exercise caution with pre-bagged salad mixes and to thoroughly wash, scrub or discard outer leaves of fresh produce before eating. Health officials say updates on the investigation, including any potential recalls, are expected in the coming days as case confirmations continue to roll in from state health departments across the country.