New infections with cyclospora, the “explosive” diarrhea-causing parasite that’s sickened thousands of Americans this summer, appear to be on a downward trend, according to new data
The parasitic illness, also known as cyclosporiasis, normally ramps up during the warmer months in the United States. But this year, cases have surged to record-high levels
More than 17,100 confirmed cases have been reported by 48 states since May 1, according to the latest data from the U.S. Centers for Disease Control and Prevention published on Aug. 25. Some 11,800 probable cases are still under investigation
During the same time period last summer, only 1,180 cases were reported to the CDC. In recent decades, the U.S. has seen an average of 2,000–3,000 cyclosporiasis per year
The stomach-churning infection causes episodes of severe, watery diarrhea, and it usually isn’t life-threatening. However, more than 900 people have been hospitalized and two people have died from the infection in the U.S. since May
Fueling the recent surge of cyclosporiasis cases is a massive, multistate outbreak linked to contaminated iceberg lettuce from Mexico supplied by Taylor Farms, which issued a nationwide recall of all its affected products in July
Although the case count continues to rise in Michigan and other states, there are promising signs that new diagnoses are slowing, Dr. Kavita Patel, health policy expert and NBC News medical contributor, said on TODAY in a segment aired Aug. 19
“The curve are showing us that the cases and the diagnoses are slowing down,” she added
However, the CDC and U.S. Food and Drug Administration are still investigating at least six other cyclosporiasis outbreaks and potential
In the meantime, many Americans are left wondering what’s safe to eat. As cyclospora is often linked to raw produce, is it still necessary to avoid certain fruits and vegetables?
Cyclosporiasis is caused by Cyclospora cayetanensis, a microscopic parasite which infects the small intestine
People become infected with cyclospora by consuming food or water contaminated with particles of feces from an infected person, Kali Kniel, Ph.D., professor of microbial food safety at the University of Delaware, tells TODAY.com
Person-to-person spread is extremely unlikely. That’s because after the parasite is shed in feces, it takes one to two weeks living outside the body to mature and become infectious, says Kniel
Cyclospora can get into produce if it’s grown in soil or washed with water contaminated with feces; fresh fruits and vegetables are common culprits, she adds
It can take anywhere from two days to two weeks after being exposed to cyclospora to show signs of illness
The hallmark symptom of cyclosporiasis is watery and sometimes “explosive” diarrhea, per the CDC. If left untreated, the diarrhea can last for several weeks, says Kniel
Other common signs include abdominal cramping, bloating, appetite loss, increased flatulence and fatigue, per the CDC
Most healthy people will recover from cyclosporiasis on their own without medical care, Kniel notes. However, the diarrhea can persist and occur in cycles, known as relapses, for up to a month or longer if left untreated
Cyclosporiasis can be treated effectively with a combination antibiotic. “We are seeing hospitalizations, so if you do get sick, good hydration is critical, and so is getting clinical care because this can be treated,” Kniel explains
Cyclosporiasis cases and diagnoses may be slowing down, says Patel, but outbreaks of the parasitic infection are not over
Currently, four of the seven cylcospora outbreaks under investigation by the FDA are considered ongoing, according to the agency’s foodborne illness tracker. In six of these outbreaks, including the three listed as “ended,” the
“There are still a number of outbreaks that do not have an identified thick of it,” said Patel
In the U.S., cyclosporiasis season usually lasts from May through Aug. 31, per the CDC. However, cases could continue to rise later than usual this year
So far, only one outbreak — the nation’s largest — has been linked to a particular food, iceberg lettuce. The lettuce was supplied by Taylor Farms de Mexico and served at restaurants and retailers, but has since been recalled and is no longer available
More than 10,900 cases associated with this outbreak have been reported across 17 states, per the FDA: Arkansas, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Massachusetts, Michigan, Missouri, Nebraska, New Hampshire, North Carolina, Ohio, Oklahoma, Pennsylvania, and West Virginia
In Michigan, the hardest-hit state, cyclosporiasis case reports and diarrhea-related emergency department visits are slowing down, NBC News reported previously
The FDA has not specified where the other outbreaks under investigation are located, and it’s unclear if these are connected
“There may be multiple unrelated outbreaks going on at the same time,” Donald Schaffner, Ph.D., professor of food microbiology in the Department of Food Science at Rutgers University, tells TODAY.com. There’s likely more than one food or water
Cyclospora is a particularly challenging parasite to track. Due to its long incubation period and lags in testing, it can take weeks for cases to be confirmed and investigated
As a result, only a small portion of cyclosporiasis cases reported every year get traced back to a particular food
Nearly 29,000 confirmed and probable cases of cyclosporiasis have been reported in 48 states (including the District of Columbia) since May 1, per the latest CDC data
Only two states have reported zero cases since May 1: Hawaii and Delaware
The true number of cyclospora infections in the U.S. is likely higher than the numbers currently being reported — that’s because many people recover on their own and never get tested for cyclospora, per the CDC
Here’s which states are reporting the most infections:
Michigan is being hit the hardest. As of Aug. 20, the state has reported over 14,277 cyclosporiasis cases, 335 hospitalizations and two deaths, per the Michigan Department of Health and Human Services
Neighboring Ohio has reported over 5,800 cases this summer, per information from the state’s health department obtained by NBC News
Indiana has recorded over 2,090 cyclosporiasis cases since May 1, according to the Indiana Department of Health
Missouri’s cyclosporiasis case count has surpassed 2,000, per thestate’s health department
Illinois reported nearly 1,000 cyclosporiasis cases this summer, per the latest data from the Illinois Department of Public Health
So far, one recall has been issued due to cyclospora concerns
On Aug. 17, Taylor Fresh Foods announced it was voluntarily removing all its iceberg lettuce
However, the recalled products have expiration dates up to Aug. 3, which means they’re long-expired, says Schaffner
“The best-by dates for these recalled products have passed and they should no longer be available in stores or restaurants,” the FDA said
The affected products (see a full list) were distributed through July 16 to food service locations and retailers in 31 states, per the FDA. These include Taco Bell and Walmart, which sold two recalled items under the brand Marketside:
- Iceberg Salad: 12 oz., 24 oz.; best if used by July 18–Aug. 3, 2026
- Shredded Lettuce: 8 oz., 16 oz.; best if used by July 18–Aug. 3, 2026
Health officials have urged consumers who purchased recalled lettuce and still have it in their fridge or freezer to discard it immediately
If you’ve been nervous to enjoy salad this summer, you’re not alone. Fortunately, lettuce is generally safe to eat, the experts say
“I haven’t changed my habits. I had a salad for dinner last night. I’m going to have a salad for dinner tonight,” Schaffner says
Due to its limited shelf life, the contaminated iceberg lettuce linked to the 17-state outbreak is long gone
The recalled Taylor Farms lettuce is no longer available in stores or being served at restaurants, per the FDA. Taco Bell removed all affected lettuce from its supply chain in mid-July
Michigan health officials have also lifted lettuce warnings, encouraging residents to resume their normal habits
“We still may see new cases (reported) in that outbreak, but that’s from people that ate lettuce weeks ago,” Schaffner says
Food safety experts recommend people stay up to date on recalls and food safety alerts
“Almost all servings of fresh fruits and vegetables that you can buy on the market today are not linked to this outbreak,” says Schaffner
Historically, past cyclospora outbreaks in the U.S. have been linked to certain types of produce — specifically, fruits and vegetables that are eaten raw and hard to clean thoroughly. These include lettuce, cilantro, basil, raspberries and green onion
Avoiding foods implicated in past outbreaks isn’t necessary, says Schaffner, but the choice is up to consumers
Any food could become tainted if it comes into contact with soil, water or unwashed hands contaminated with feces from an infected person
“No fresh produce is completely risk-free,” Wade Syers, a food safety specialist with Michigan State University Extension, tells TODAY.com
However, some types of fruit and vegetables are considered lower-risk because they are less likely to become contaminated and haven’t been linked to past cyclospora outbreaks
These include:
- Fruits and vegetables that are cooked
- Commercially blanched and frozen produce
- Canned fruits and vegetables
- Produce with a removable peel
- Produce with a thick, smooth surface
The best way to prevent cyclospora is by cooking food to least 158 degrees Fahrenheit, as heat destroys the parasite
Washing produce thoroughly can reduce the risk of foodborne illness, but it won’t eliminate cyclospora entirely
- Wash your hands with soap and hot water before and after handling raw produce.
- Scrub all fresh vegetables and fruits with a produce brush under clean, running water.
- Opt for whole head lettuce over bagged or boxed salad.
- Remove the outer layer of leaves or the peel, if possible. Run the inner leaves under running water.
- Cut or peel off damaged areas of produce before eating.
People with weakened immune systems may need to take extra precautions and should consult their doctor about how to avoid foodborne illness, says Kniel
If you develop cyclospora symptoms, contact your doctor
