Health
Massachusetts is among more than a dozen states with documented cases of cyclosporiasis, a stomach-churning parasitic infection spread through food or water.
Past cyclospora outbreaks in the U.S. have been linked to fresh produce, including raspberries, basil, cilantro, scallions, snow peas, and bagged salads, according to DPH. Darko Vojinovic / AP, File
July 8, 2026 | 12:43 PM
3 minutes to read
More fearsome than a bowl of unrefrigerated potato salad, the stomach-churning cyclospora parasite has officially made an appearance in Massachusetts.
Spread through contaminated food or water and treatable with antibiotics, cyclospora can cause weeks of explosive diarrhea, cramping, nausea, and fatigue, according to the state’s Department of Public Health.
Massachusetts is among more than a dozen states with documented cases of cyclosporiasis — the infection caused by cyclospora — since May 1, according to the U.S. Centers for Disease Control and Prevention. The CDC reports 145 cyclosporiasis cases nationwide through June 16, though the agency’s tracker notably doesn’t include a massive outbreak in Michigan, which has logged nearly 800 cases in recent weeks.
Across the U.S., there have been 20 hospitalizations linked to cyclospora, but no deaths, according to the CDC.
Public health officials in Massachusetts say there have been 18 reported cases of cyclosporiasis among Bay Staters between May 1 and July 7, which is in line with the number of cases typically seen statewide during the same period. In fact, Massachusetts previously saw more than 100 cases of cyclosporiasis during an outbreak in the spring and summer of 2019.
“Because we know that diagnosis does not always occur promptly following onset of symptoms, we anticipate that there will be additional cases reported that fall in this time frame,” DPH acknowledged.
The delayed reporting is partially because not every lab or hospital may test for cyclospora right off the bat, given the parasite is relatively uncommon, explained Dr. Zoe Weiss, director of clinical microbiology at Tufts Medical Center.
Moreover, cyclosporiasis “can be really challenging to distinguish, especially in the beginning, because a lot of foodborne illnesses can cause watery diarrhea,” Weiss noted.
“I think one important feature for cyclospora is that the diarrhea can be frequent and prolonged,” she added. “Most people will get over a foodborne illness in a couple of days, but if it’s going on for 10 days, two full weeks, or longer, that could suggest that you have a parasite infection, potentially.”
While cyclospora spreads through food or water contaminated with feces, Weiss noted the parasite needs about one to two weeks to mature outside the human body before it can become infectious, making it unlikely someone with cyclosporiasis could spread it directly to a family member or close contact. On the other hand, she noted, the parasite has a longer period for symptom onset, which can make it difficult for public health officials to pinpoint a source.
“A lot of the other bacterial foodborne illnesses, like salmonella, Shigella, Campylobacter, they tend to have a short onset, like one to five days of onset from when you get exposed, whereas cyclospora is about a week to two weeks, and that can actually make it even more challenging to figure out where it came from,” Weiss explained. “How is someone supposed to remember that two weeks ago they ate a strawberry, or a raspberry, or something?”
Past outbreaks in the U.S. have been linked to fresh produce, including raspberries, basil, cilantro, scallions, snow peas, and bagged salads, according to DPH. State health officials say there’s no clear evidence of a cluster of cases in Massachusetts at this time, and the CDC likewise reports there is nothing to suggest a single, multi-state outbreak linking all cyclosporiasis cases.
According to DPH, washing fruits and vegetables with water and a brush may help get rid of cyclospora, though cooking produce will kill the parasite outright. Peeled fruits and vegetables should also be safe to eat, the agency noted.
So, should Massachusetts residents be concerned about cyclospora cases ramping up?
“I think it’s reasonable to be vigilant about if you are developing new, sudden-onset diarrhea, and you’re not aware that you ate anything unusual, and it’s kind of consistent,” Weiss said. “While previously the focus was on testing just in the Michigan area, now that we have cases in other places, I actually think health care providers need to be more aware of this being a possibility.”
Abby Patkin is a general assignment news reporter whose work touches on public transit, crime, health, and everything in between.
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