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(NEXSTAR) — There have been more than 1,600 cases of cyclosporiasis confirmed in the U.S. since May 1, the Centers for Disease Control and Prevention reports, but the true case count could be much, much higher, the agency warns.
As of Monday, 1,645 confirmed cases of cyclosporiasis across 34 states have been reported to the CDC. That’s almost six times the 249 cases reported this time last year.
In an alert to health care providers, the CDC warned that there are more than 5,100 cases that require further testing to confirm the illness was locally acquired.
The true number of people who have fallen ill could be even higher than that, as “cyclosporiasis is often underdiagnosed and underreported,” the CDC says.
While cyclosporiasis cases can occur in people who travel to countries where the cyclospora parasite is more prevalent, the CDC says that all 1,645 cases were reported among patients who did not leave the U.S. before becoming sick.
The CDC says it has not yet identified a common cause between the cases, but health officials in Michigan – where the outbreak is the worst – suspect lettuce or salad greens may be to blame. Outbreaks of cyclosporiasis in the U.S. have previously been linked to fresh produce.
In its alert Tuesday, the CDC urged health care providers to “specifically request diagnostic testing” for the “explosive” diarrhea-causing parasite when it is suspected among patients.
In 47 states, the District of Columbia and New York City, cyclosporiasis is considered a nationally notifiable condition.
Where cyclosporiasis cases have been reported
As of July 14, a review of local reports and state health data shows 39 states have reported at least one case of cyclosporiasis this year.
How states are reporting data varies. Some are using year-to-date data, while others are reporting more recent cases. Not all cases are linked to the recent surge, and some are considered probable, not confirmed. The CDC only reports the latter.
Michigan, the apparent hotspot in the outbreak, has now reported more than 3,000 cases.
What to know if you get cyclosporiasis
Not everyone who becomes ill has symptoms or will require treatment. Among those who do have symptoms, as the CDC and Cleveland Clinic explain, the main issue is frequent, watery diarrhea that can be loud and “sometimes explosive.”
Other symptoms can include a loss of appetite, nausea, vomiting, stomach cramps, “bloating, including burping and farting,” low-grade fever, and extreme tiredness. These symptoms can set in between two days and two weeks after infection.
For some people, illness will “self-resolve after a few days,” Dr. Katie Theoktisto of Baylor Scott & White told Nexstar’s KXAN.
“If you’re having a diarrheal illness that’s lasting over a week or two, it’s probably something unusual,” she warned, saying that “those with prolonged symptoms should seek care from their health care providers.”
A stool test is necessary to determine whether you have cyclosporiasis.
Young children, pregnant women, elderly people, and those with weakened immune systems may be more severely impacted by the parasite, Theoktisto said. They may also experience a recurrence of symptoms.
Woman describes feeling ‘sickest I’ve ever been’
A Southern California woman who told Nexstar’s KTLA that she had recently recovered from cyclosporiasis said the parasite made her “the sickest I’ve ever been.” She described days of severe gastrointestinal illness, saying she suffered intense stomach pain and was unable to keep food down.
“It was coming out of both ends,” she said. “Every time I tried to eat, it was like a stabbing pain in my stomach, and I couldn’t keep anything down.”
After several days of taking antibiotics, the woman said she started to feel better.
“I would not wish that on my worst enemy,” she remarked.
KTLA’s Josh DuBose contributed to this report.
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