Horrifying map reveals massive true scale of ‘explosive diarrhea’ parasite outbreak:
The true scale of America’s explosive diarrhea parasite outbreak may be far worse than official figures suggest.
An exclusive Daily Mail investigation has uncovered nearly 5,400 cases of cyclosporiasis – more than three times the 1,645 infections currently listed by the Centers for Disease Control and Prevention (CDC).
The disparity raises questions over whether the nation’s leading public health agency is significantly underestimating the scale of the outbreak.
Cases of cyclosporiasis – an infection caused by the Cyclospora parasite that can trigger explosive diarrhea – first began rising in the US in May, with infections reported across several states throughout June as public health officials raced to identify the source.
In its first report on the domestic outbreak, published last month, the CDC recorded 145 cases across 17 states, including 20 hospitalizations.
Yet at the same time, the Michigan Department of Health alone was reporting 150 cases.
The discrepancy prompted the Daily Mail to request data from all 50 state health departments.
Forty-eight responded, with 41 confirming cases, revealing a dramatically different picture of the outbreak – as our exclusive state-by-state map shows.
Insiders told the Daily Mail that deep cuts to CDC funding and widespread staff burnout are likely contributing to the undercount and hampering outbreak surveillance.
People become infected with cyclosporiasis by eating food or drinking water contaminated with the Cyclospora parasite, most commonly through fresh produce such as leafy greens, herbs and berries.
In the US, most cases are typically linked to international travel or imported produce from regions where the parasite is common, including Mexico, Central America, South America and the Caribbean.
So when people with no recent travel history began falling ill across several states this spring, it raised fears contaminated food was circulating through the US supply chain. Public health officials have spent weeks trying to identify the source, but no single food item has yet been linked to the outbreak.
The figures obtained by the Daily Mail from individual state health departments are not directly comparable with the CDC’s totals because some states distinguish between domestically acquired and travel-related infections, while others combine them.
Even so, the state data suggests the overall burden of cyclosporiasis is substantially greater than the CDC’s public figures indicate.
‘The CDC numbers are almost certainly an undercount,’ Dr Amy Edwards, assistant professor of pediatrics at the School of Medicine at Case Western Reserve University, told the Daily Mail.
‘While most patients require treatment, some will clear the infection on their own and are therefore unlikely to receive a diagnosis.’
Cases have been confirmed to the Daily Mail by every state except New Hampshire and Nebraska, whose health departments did not respond to requests for comment.
Georgia officials said they had recorded cases but declined to provide an exact figure. Hawaii, Minnesota, Mississippi, Utah and Vermont all confirmed they had recorded no cases.
The CDC does not specify which states classify cyclosporiasis as a reportable disease. However, Idaho told the Daily Mail the infection is not reportable there, meaning the state keeps no official records.
Looking only at states that provided figures dating back to May 1, several reported far more infections than appeared in CDC data.
California confirmed 41 cases, compared with 10 or fewer reported by the CDC. Florida recorded 40 cases, versus 11 to 30 in federal data, while Indiana logged 206 compared with 31 to 80.
Elsewhere, Iowa and Maryland each confirmed 28 cases despite the CDC listing 10 or fewer. Louisiana reported 23 cases under investigation, compared with 10 or fewer in the federal data, while Ohio confirmed 177 cases versus 10 or fewer.
The biggest discrepancy was in Michigan, where the state confirmed 3,762 cases to the Daily Mail, compared with the CDC’s reported range of 501 to 900.
In its latest update on July 14, the CDC said: ‘CDC is aware that states are likely to report higher case counts of cyclosporiasis than reflected in CDC data and is working closely with states to update numbers as additional cases are confirmed.
Cyclospora is typically found on fresh produce, such as lettuce, that come into contact with water contaminated by feces
‘Since May 1, 2026, CDC has received reports of 1,645 confirmed domestic cases of cyclosporiasis and is aware of more than 5,100 cases that require further analysis to confirm the illness as domestically acquired cyclosporiasis.
‘So far this year, multiple states have reported an increase in cases compared to the same period in 2025.’
The agency also said it ‘is concerned about the increase in cases since the start of May.’
Experts told the Daily Mail that while some lag between state and federal reporting is expected during any multistate outbreak, the current gap appears unusually large.
‘Local authorities are always faster because they are boots on the ground,’ said Dr Amy Edwards.
‘However, the CDC is particularly slow this time because of significant cuts made recently to both budget and staff.’
Dr Darin Detwiler, a food safety expert at Michigan State University, said the CDC verifies every case before adding it to its national totals, creating an inevitable delay.
‘What makes this situation unusual is the scale of the gap,’ he said.
Tracing the source of the outbreak has also proved difficult because Cyclospora has an incubation period of one to three weeks.
By the time investigators interview patients, they are asking them to remember every salad, herb or berry they ate weeks earlier. In many cases the food has already been eaten or discarded, while the supply chain may span multiple farms, distributors, retailers and even countries.
No source of the current outbreak has been identified, though Michigan health officials say early evidence points to lettuce or salad greens as a possible culprit.
No specific variety, grower or supplier has been named.
However, federal and state health officials are reportedly investigating Taco Bell as a possible source, two people familiar with the investigation told The Washington Post on condition of anonymity.
Previous outbreaks have been linked to bagged salad kits, cilantro, basil and other leafy greens.
Fresh produce can become contaminated if it is washed or irrigated with water contaminated by human sewage.
‘Cyclospora is a parasite that only infects humans,’ Edwards said.
The cyclospora parasite (pictured above) causes cyclosporiasis, an infection that leads to diarrhea, severe cramping, nausea and vomiting and fatigue
Once contaminated, produce cannot be reliably cleaned by simply rinsing it.
‘Rinsing is not a very good way of getting rid of microbial contamination, whether it’s a virus, bacterium or parasite,’ said Dr Donald W. Schaffner, chair of the Department of Food Science at Rutgers University.
He estimates washing removes about 90 percent of microorganisms, but said that may still leave enough parasites behind to cause illness. Cooking produce, however, reliably kills the parasite.
Cyclosporiasis typically causes explosive diarrhea, abdominal cramping, nausea, vomiting and fatigue.
Unlike norovirus or routine food poisoning, however, symptoms often come and go rather than resolving after a few days.
‘The symptoms of Cyclospora are somewhat unusual in that they consist of watery diarrhea, followed by periods of recovery, followed by periods of recurrence,’ Schaffner said.
Without treatment, experts say the illness can persist for weeks or repeatedly return.
‘People often mistake Cyclospora for a stomach bug that will quickly pass, when in reality it may not,’ Detwiler said.
Anyone with diarrhea lasting more than a few days should seek medical care and specifically ask for a Cyclospora test, as it is not routinely ordered, said Dr Swapnil Patel, vice chair of medicine at Hackensack Meridian Jersey Shore University Medical Center.
The test detects Cyclospora DNA in stool samples and typically requires one to three samples.
Treatment consists of the antibiotic trimethoprim-sulfamethoxazole, sold under the brand names Bactrim, Septra and Cotrim.
Patel also advised patients to stay hydrated with water, sports drinks and clear broths, and to stick to bland foods such as bananas, rice, applesauce and toast while recovering.
He also warned against taking over-the-counter anti-diarrheal medicines such as Imodium without first consulting a doctor, as they may slow the body’s ability to clear the parasite.
Brelynn Daniels contracted cyclosporiasis and said her stomach cramping was ‘viscous’ and she thought she ‘felt my liver rip’
For one Ohio woman, the illness struck within hours of eating lettuce she said looked brown and wilted.
Brelynn Daniels, from Ohio – where 171 cases of cyclosporiasis have been reported since June – said she became violently ill after eating a salad from a local restaurant on June 24.
‘By that night, I was deathly ill,’ she told WTVG. ‘It was just all water, very violent diarrhea.’
After five days her symptoms appeared to ease, only to return with a vengeance – a hallmark of untreated Cyclospora infection.
‘I thought I was on the mend, and then it just took another turn,’ she said. ‘I was back with violent diarrhea, an upset stomach, severe abdominal cramping and nausea. I couldn’t keep any solid food down.’
It wasn’t until the 10th day of her illness, after seeing news reports about the outbreak, that she went to the emergency room.
Tests on a stool sample confirmed Cyclospora, and doctors prescribed antibiotics.
Nearly three weeks later, Daniels said she was still experiencing occasional symptoms and remained on medication.
‘It was pretty bad. It’s embarrassing how bad it was,’ she said. ‘There were moments where I was literally just camped out in the bathroom.’
She added that the abdominal pain was so intense she ‘felt my liver rip.’