Multiple US states see alarming increase in cases of parasitic illness that causes ‘explosive’ diarrhea
Almost 700 cases were reported to Michigan health department by Monday, up from 170 six days earlier
Cases of cyclosporiasis – a parasitic illness that causes “explosive”, watery diarrhea – have grown exponentially in recent days, health officials said, with an abnormally large outbreak reported in Michigan.
Almost 700 cases were reported to the state’s health department by Monday, ABC News said, up from 170 six days earlier, and almost 14 times Michigan’s average annual caseload of 50.
On Friday, the Centers for Disease Control and Prevention (CDC) said there were more than 400 cases across 18 states, and that it was working with the US Food and Drug Administration (FDA) to investigate the “alarming” clusters.
“The true number of people sick with cyclosporiasis was likely higher than the number reported,” the CDC said in a bulletin, noting that many victims recover without seeking medical care or testing.
Although cyclosporiasis is rarely life-threatening, and no deaths have been reported from the current outbreak, the intestinal illness can have severe effects.
Symptoms include cramps, nausea, fatigue, loss of appetite, low-grade fever and vomiting. “Watery diarrhea with frequent and sometimes explosive bowel movements” is the most commonly reported symptom, according to the CDC.
Cyclosporiasis is caused by the parasite cyclospora, which spreads through raw produce and water contaminated with human feces. Previous outbreaks have been linked to fresh fruit and vegetables, including a surge of cases in Florida in 2022 caused by contaminated lettuce in packaged salad kits that sickened hundreds of people.
The average time from ingestion to symptoms appearing is about one week, but can range from two days to about two weeks, health officials said, noting that it is not usually transmitted from person to person.
In Michigan, experts predict cases will continue to rise as people become aware of publicity over the current outbreak and seek testing and treatment.
Dr Natasha Bagdasarian, Michigan’s chief medical executive, told ABC: “There is a significant lag time between exposure to contaminated produce or contaminated materials and development of symptoms.”
She added that the 678 cases reported as of Monday represented “a moving target”.
The ABC report on Monday also noted a significant rise in cases in Ohio, which numbered 177 as of 2 July, the state’s health department said, with 171 of those reported since 20 June.
While officials work to establish any link between clusters, which have emerged most visibly in the south-east of Michigan, including Detroit, there is no suggestion of a connection to outbreaks in other states, the CDC said.
According to the center’s most recent update on 1 July, cases had been reported in 17 states, and 20 people hospitalized. Summer months traditionally see a rise in cases, the CDC said, resulting in a “cyclosporiasis season” from 1 May to 31 August.
Health officials recommend cooking fresh produce where possible to reduce the risk of illness, or thoroughly washing it in clean, running water.

Basically almost 700 cases were reported to Michigan health department by Monday, up from 170 six days. What matters is whether anything changes because of it.
18 states is hard to ignore, no matter which side you are on.
What stands out is almost 700 cases were reported to Michigan health department by Monday, up from 170 six days. That is the part worth paying attention to.
If symptoms include cramps, nausea, fatigue, loss of appetite, low-grade fever and vomiting, then the bigger picture starts to look very different.
When you look at although cyclosporiasis is rarely life-threatening, and no deaths have been reported from the current outbreak, the intestinal illness can have severe effects, the implications are hard to ignore.
Basically although cyclosporiasis is rarely life-threatening, and no deaths have been reported from the current outbreak, the intestinal illness can have severe effects. What matters is whether anything changes because of it.
Reading that almost 700 cases were reported to the state’s health department by Monday, ABC News said, up from 170 six days earlier, and almost 14 times Michigan’s average annual caseload of 50 — hard to argue with the logic there.
18 states — and that is probably just the official count.
20 people — and that is probably just the official count.
The detail about although cyclosporiasis is rarely life-threatening, and no deaths have been reported from the current outbreak, the intestinal illness can have severe effects is something people should sit with.
When you look at almost 700 cases were reported to Michigan health department by Monday, up from 170 six days, the implications are hard to ignore.
The detail about symptoms include cramps, nausea, fatigue, loss of appetite, low-grade fever and vomiting is something people should sit with.
In other words although cyclosporiasis is rarely life-threatening, and no deaths have been reported from the current outbreak, the intestinal illness can have severe effects. Curious to see how this develops.
Almost 700 cases were reported to the state’s health department by Monday, ABC News said, up from 170 six days earlier, and almost 14 times Michigan’s average annual caseload of 50. Meanwhile although cyclosporiasis is rarely life-threatening, and no deaths have been reported from the current outbreak, the intestinal illness can have severe effects.
The detail about cyclosporiasis is caused by the parasite cyclospora, which spreads through raw produce and water contaminated with human feces is something people should sit with.