Nearly 3,000 individuals have reported a gastrointestinal illness known as cyclosporiasis, which is characterized by severe, watery diarrhea, as per state health departments nationwide. The Centers for Disease Control and Prevention (CDC) announced on Friday that 31 states have documented cases, resulting in 86 hospitalizations.
While health officials are racing to identify the source of these illnesses, the CDC mentioned that it’s uncertain if the outbreaks in various states are linked.
These figures show a significant increase compared to last year. So far, the agency has confirmed 843 cases, all of which were contracted in the U.S., and investigations are ongoing for over 1,500 additional cases. Fortunately, there have been no reported fatalities.
Michigan has been particularly hard hit, with 1,562 confirmed cases as of Friday. The cyclospora parasite has also been reported in neighboring Ohio, along with other states like Colorado, Illinois, New York, North Carolina, Texas, and Wisconsin.
Dr. Natasha Bagdasarian, Michigan’s chief medical executive, described the sudden increase as “highly unusual,” noting that the state typically encounters about 40 to 50 cases yearly. She explained that labs are currently working to sequence the parasite’s genome to trace its origin.
“By determining if the isolates are closely related, we can ascertain if there was a common source, allowing us to investigate the contamination more thoroughly,” she added.
Fresh produce has a history of being linked to such outbreaks, as cyclospora parasites tend to adhere to fruits, vegetables, and herbs, which are challenging to rinse completely.
According to Dianna Blau, acting chief of the CDC’s Parasitic Disease Branch, investigating these outbreaks is made difficult because symptoms can take a week or more to manifest. “In an average year, only a small percentage of cases are traced back to a specific food item,” she indicated.
Whatever is currently causing illnesses was likely consumed more than a week prior. Often, the tainted food is mixed with others—like cilantro in salsa or bagged lettuce in salads—making it easy to overlook afterwards.
The Food and Drug Administration (FDA) stated it is “actively engaged” with state partners, although no product recalls related to these outbreaks have been issued.
Where is it spreading?
This summer, Michigan has been the most impacted, a time when cases of cyclosporiasis typically rise. By Friday, the state had confirmed 1,562 cases with at least 36 hospitalizations, mostly clustered in the southeast region near Ohio, which is also facing an outbreak.
As of July 2, the Ohio Health Department reported 177 cases and 28 hospitalizations, and recent numbers from the Toledo-Lucas Health Department indicate an additional 306 cases. New York has reported 394 cases, while Illinois has accounted for 141 thus far.
An NBC News survey of state health departments reveals that 2,912 cases have been reported or confirmed nationwide. Last year, there were around 2,700 cases. Typically, cases rise from May 1 to August 31.
What is cyclosporiasis and what are its symptoms?
Cyclosporiasis is a foodborne disease caused by a microscopic parasite called cyclospora, usually associated with fresh produce. Previous outbreaks have involved raspberries, bagged lettuce, salads, cilantro, and sometimes even contaminated water.
Symptoms usually start about a week after exposure and can begin with flu-like issues such as fatigue and body aches.
The hallmark of cyclosporiasis is severe, watery diarrhea that can be overwhelming. Additional symptoms may include gas, stomach cramps, and nausea, which often result in a loss of appetite. Low-grade fevers are not common.
The illness is treated with antibiotics, typically Bactrim. If left untreated, symptoms can persist for weeks. Staying hydrated is crucial, particularly due to diarrhea. On average, about 10% of patients end up hospitalized, usually due to dehydration. Vulnerable groups include young children, older adults, and individuals with weakened immune systems.
Typically, test results are available in about 24 hours, but high demand for testing in some areas has stretched wait times to two to three days.
How is the illness tracked?
Last July, the CDC made tracking cyclospora optional when it scaled back its Foodborne Diseases Active Surveillance Network, raising concerns among food safety experts that such changes would hinder outbreak identification and responses.
Donald Schaffner, a food microbiology professor, said it’s unclear if this has affected the current outbreaks. “Could we have identified these issues sooner? Could we be uncovering more?” he questioned, stressing the need for improved tracking.
Blau mentioned that there haven’t been changes in how cyclosporiasis cases are reported. State and local health departments are tasked with interviewing affected individuals to determine their recent food intake and analyzing grocery receipts for similar products. The CDC is providing technical support to states and assisting in sample analysis as part of the investigation to find potential connections between outbreaks.
How does it spread?
Unlike respiratory viruses, cyclosporiasis does not transmit from person to person. Even when a person sheds the parasite, it isn’t immediately infectious to others.
It requires days or weeks in the environment to become capable of causing a new infection. Although cyclospora don’t typically persist on surfaces, food safety experts recommend cleaning counter spaces and cutting boards with soap and water.
Staying safe from cyclosporiasis
The only guaranteed method to eliminate the parasite is by cooking food. While washing produce can lower the risk of cyclosporiasis, it doesn’t completely remove it.
Janet Buffer, a senior manager at the Institute for Food Safety and Nutrition Security, suggests avoiding dish soap to prevent residue on produce that could cause stomach issues.
She recommends vigorously agitating the surface of fruit and vegetables instead.
Cleaning raspberries can be tricky due to their tiny hairs that help the parasite cling on. While there is no current evidence to suggest berries are involved in these outbreaks, Driscoll’s, the leading berry supplier, has reported no inquiries from health authorities about a potential link.
The Michigan Health and Human Services Department advises considering cooking raspberries in dishes like pies or jams. Freezing might kill the parasite, but it’s not a given.
To reduce the risk of cyclosporiasis, Michigan health officials offer these tips:
- Choose whole heads of lettuce over prewashed, bagged varieties and rinse the remaining leaves after removing the outer ones.
- Separate and thoroughly wash cilantro and basil leaves under running water.
- Trim green onions by cutting off the root end and removing the outer layer before washing.
Until a source is identified, Rutgers’ Schaffner points out the importance of not avoiding fresh fruits and vegetables. “We recognize fresh produce contributes to a healthy diet. Cyclosporiasis tends to peak between May and August, which coincides with fresh produce season,” he stated. “Personally, I’m not changing my eating habits.”
