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Cyclospora Cases Are on the Rise: What Older Adults Should Know
The intestinal parasite can cause weeks of diarrhea, and routine stool testing may miss it
Cyclospora cayetanensis is a bacteria that can cause watery diarrhea, cramps, nausea and other symptoms that may last for weeks without treatment.
Courtesy CDC.gov
Key takeaways
- Cases of cyclosporiasis, which can cause severe, explosive diarrhea, continue to rise in the U.S.
- Federal health officials have linked an outbreak to iceberg lettuce sourced from central Mexico, and are investigating the source of other outbreaks.
- Dehydration from the illness is a chief concern for older adults.
This summer, thousands of people across the United States have been sickened — and two have died — from cyclospora, a microscopic parasite that can trigger weeks of severe diarrhea.
Since May 1, more than 18,200 cases have been confirmed or are under investigation across 45 states, according to the Centers for Disease Control and Prevention (CDC). The two deaths occurred in Michigan, state health officials said, and both involved people with “significant underlying health conditions.”
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One multistate outbreak involving at least 1,947 cases and nearly 100 hospitalizations has been traced to iceberg lettuce sourced from central Mexico, prompting the supplier, Taylor Farms de Mexico, to recall products sold to restaurants, retail stores and food distributors. Consumers who bought any recalled lettuce should not eat it and should throw it away, health officials say.
Officials are also investigating other unrelated outbreaks and cases of cyclosporiasis, the illness caused by cyclospora. The parasite spreads through food or water contaminated with feces and tends to peak in the summer months.
Here’s what older adults need to know.
What to know about cyclospora
Cyclospora can upset your gut and cause watery diarrhea that lasts much longer than the typical stomach bug, the CDC says.
Bowel movements can be frequent and sometimes explosive. Other symptoms can include loss of appetite, weight loss, stomach cramps, bloating, gas, nausea and fatigue. Some people may also have vomiting, body aches or a low-grade fever.
Symptoms usually start about a week after exposure, though they can begin sooner or take more than two weeks to appear. Without treatment, the illness can last from a few days to more than a month. Symptoms can also seem to go away, then come back.
“Cyclospora characteristically causes a waxing and waning pattern of diarrhea. It comes and goes but never fully resolves,” Dr. Cory Fisher, a family medicine physician at Cleveland Clinic, tells AARP.
Cyclospora infections are most common in the U.S. during warm-weather months, health officials say, and cases are expected to continue rising through late August.
What this means for older adults
The CDC says cyclosporiasis can last longer or become more severe in people with poor health or weakened immune systems. Older adults are also at high risk for severe illness because of what persistent diarrhea can do to the body.
“The primary concern is dehydration resulting from prolonged, watery diarrhea,” says Dr. Luis Marcos, an infectious disease physician and professor of medicine at Stony Brook Medicine in New York. “Older adults are more vulnerable to the complications of dehydration because they are more likely to have underlying medical conditions and take medications that affect fluid balance.”
Those complications can include electrolyte problems, acute kidney injury, weakness, dizziness, falls and worsening of chronic conditions, Marcos says. According to health officials, the two deaths in Michigan occurred in people with “significant underlying health conditions that may have been impacted by cyclosporiasis and dehydration.”
Warning signs of dehydration can include excessive thirst, dry mouth or skin, little or no urination, weakness, dizziness, lightheadedness, fatigue and dark-colored urine. If left untreated, dehydration from diarrhea can be life-threatening, the Mayo Clinic says.
Health experts say you should call a doctor if diarrhea is severe (more than six to eight episodes per day, Fisher says) or lasts more than two to three days without improvement. And Marcos says you should call sooner if there is dizziness, confusion, decreased urination, dry mouth or a rapid heartbeat, even after just one or two days of diarrhea.
Seek medical attention promptly for blood in the stool, persistent vomiting, high fever with chills, severe abdominal pain or an inability to keep fluids down, Marcos adds.
How cyclospora spreads
People can get cyclospora by eating contaminated food or drinking contaminated water. In the U.S., past outbreaks have been linked to fresh produce, according to the CDC.
Cyclospora also does not usually spread directly from one person to another. The parasite has to spend time outside the body before it can make someone else sick, according to the CDC.
Testing can be tricky
If you have diarrhea that is not going away, ask your health care provider whether cyclospora could be the cause.
That question matters because routine stool testing may miss it. “Cyclospora is not detected by many routine stool cultures or standard gastrointestinal tests,” Marcos says.
The CDC says a specialized lab test that is not always included in a standard stool test may be required.
Cyclosporiasis is usually treated with trimethoprim-sulfamethoxazole (TMP-SMX), a combination antibiotic.
Marcos says clinicians should review a patient’s medication list before starting TMP-SMX because it can interact with blood thinners, some diabetes medications and drugs that affect potassium levels or kidney function. People with a sulfa allergy may need an infectious disease specialist because effective alternatives are limited, he says.
How to lower your risk
There are a few things you can do to lower your risk of getting sick with cyclosporiasis and other foodborne illnesses.
Follow public health advisories about outbreaks and recalled products, and follow basic food safety steps, especially when handling fresh produce.
The CDC recommends these steps:
- Cooking kills the parasite; heating food to 158°F or 70°C or higher is effective.
- Wash your hands with soap and water before and after handling or preparing raw fruits and vegetables.
- Wash fruits and vegetables under running water before eating, cutting or cooking them.
- Scrub firm produce, such as melons and cucumbers, with a clean produce brush.
- Cut away bruised or damaged areas before preparing or eating fruits and vegetables.
- Refrigerate cut, peeled or cooked fruits and vegetables within two hours.
Editor's Note: This story, first published July 7, has been updated to reflect new information.
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