Cyclospora Outbreak: The ‘Explosive Diarrhea’ Parasite Hits 18 States
The parasite spreads through contaminated fruits and vegetables — and with cases surging past 1,200 in Michigan alone and no source yet identified, here’s what to watch for and how to protect yourself.
A foodborne protozoan parasite known as Cyclospora, which causes the disease cyclosporiasis and infects the small intestine, is on the rise across 18 states. The seasonal stomach bug endemic in most tropical regions, which typically spans May through August each year, is transmitted through feces-contaminated water and produce, including basil, cilantro, musclun lettuce, raspberries, and snow peas in the U.S.
The most notable symptom is diarrheal illness, which can include watery diarrhea, abdominal cramps, nausea, and vomiting. According to the Centers for Disease Control and Prevention (CDC), the timeframe between infection and illness ranges from two days to two weeks. Symptoms can last just as long.
How Far Has the Cyclospora Outbreak Spread?
Michigan has been hit the hardest by far, with 1,251 cases as of July 9 — a staggering jump for a state that typically sees only about 50 cyclosporiasis cases in an entire year. At least 36 people there have been hospitalized, and no deaths have been reported.
Outside Michigan, the CDC counted 145 cases across 17 other states since May 1, plus another 45 among Americans who had traveled abroad — figures that lag the states’ own faster-moving counts. Investigators haven’t confirmed whether the outbreaks are linked or identified a common source, and the true number is likely higher, since many people who get sick never seek testing.
Is Cyclosporiasis Dangerous?
Not really. While outbreak numbers can seem scary, the bigger issue is identifying what caused them rather than the outbreaks themselves. For example, Michigan normally sees only about 50 cases in a full year, so the real story is the unusual surge and its source — not that cyclosporiasis is suddenly more dangerous.
While cyclosporiasis is certainly unpleasant to endure and can cause even more severe gastrointestinal distress in immunocompromised individuals and children, it is not life-threatening. Furthermore, because the parasite requires sporulation to be problematic for humans, person-to-person transmission of the disease is unlikely, as an infected person will excrete it in an unsporulated form.
Cyclospora Symptoms: How Do You Know If You Have It?
While you should always thoroughly wash your hands and rinse raw produce before cooking or consuming it, checking for Cyclospora in food or water is not feasible because the parasite is microscopic. Relying on the CDC Food Safety Alerts can better inform you of what foods to potentially avoid during a known outbreak.
There is no surefire way to confirm if you have cyclosporiasis solely from symptoms. If you are suffering from diarrhea or other intense gastrointestinal distress, it is likely best to consult a doctor. The only way to confirm if the parasite is present is through a stool sample.
There are some treatments for cyclosporiasis, including the antimicrobial trimethoprim-sulfamethoxazole, which has been shown to stop diarrhea in infected individuals, and the antibiotic ciprofloxacin, though with a slightly lower success rate.
Taking a more safe-than-sorry approach is also likely to help others, since cyclosporiasis is a nationally notifiable disease that requires doctors, labs, and hospitals to report cases to local and state health departments, which in turn report to the CDC.
