Explosive Diarrhea Parasite Sickens Hundreds Across Multiple States: What We Know So Far

Health officials are investigating a growing outbreak of Cyclospora, a foodborne parasite that has sickened hundreds of people across multiple U.S. states and sparked concern as investigators work to identify the source.

The outbreak, caused by the microscopic parasite Cyclospora cayetanensis, has led to an unusually high number of illnesses this summer. While several states have reported cases, Michigan has experienced one of the largest surges, with health officials saying reported infections have climbed far above the state’s typical annual total.

As of this week, investigators have not identified the specific food responsible for the outbreak, leaving consumers and public health officials searching for answers.

What Is Cyclospora?

Cyclospora is a microscopic parasite that infects the small intestine. People become infected by consuming food or water contaminated with the parasite, most often fresh produce.

Unlike many foodborne illnesses, Cyclospora is not commonly spread directly from one person to another because the parasite must first mature in the environment before it can infect someone else.

Previous Cyclospora outbreaks in the United States have been linked to foods such as:

• Fresh cilantro
• Basil
• Bagged salad mixes
• Lettuce
• Snow peas
• Raspberries and other fresh berries

At this time, however, health officials have not linked the current outbreak to any specific fruit, vegetable, brand, farm, or retailer.

Symptoms Can Last for Weeks

Symptoms typically begin about one week after exposure and can range from mild to severe.

Common symptoms include:

• Explosive watery diarrhea
• Frequent bowel movements
• Severe stomach cramps
• Nausea
• Loss of appetite
• Fatigue
• Weight loss
• Low-grade fever

One of the challenges with Cyclospora is that symptoms may improve, then return days later. Without treatment, illness can last several weeks or even months.

Hundreds of Cases Reported

Health departments across multiple states have reported an increase in Cyclospora infections this summer, prompting an ongoing investigation by state and federal officials.

Michigan has seen one of the most dramatic spikes. According to state health officials, the number of reported infections has risen to hundreds of cases, far exceeding what the state typically records in an entire year.

The Centers for Disease Control and Prevention (CDC) is also monitoring a multistate outbreak as investigators interview patients and trace where they purchased or consumed food before becoming ill.

Because many fresh produce items are distributed nationally through complex supply chains, it can take weeks before investigators identify a common source.

Who Is Most at Risk?

While many healthy adults recover with treatment, some groups face a greater risk of serious illness, including:

• Older adults
• Young children
• Pregnant people
• Individuals with weakened immune systems

Anyone experiencing prolonged diarrhea should seek medical attention, especially if signs of dehydration develop.

How Is Cyclospora Treated?

Doctors often prescribe the antibiotic trimethoprim-sulfamethoxazole (TMP-SMX), which is considered the standard treatment for Cyclospora infections.

Because severe diarrhea can quickly lead to dehydration, patients are also encouraged to drink plenty of fluids and seek medical care if symptoms worsen.

What Consumers Should Know

Since investigators have not yet identified the contaminated food responsible for the outbreak, health officials recommend taking extra precautions when preparing fresh produce.

Consumers should:

• Wash fruits and vegetables before eating them.
• Refrigerate perishable produce promptly.
• Follow any future recall notices issued by health officials.
• Contact a healthcare provider if diarrhea lasts more than a few days or becomes severe.

Although washing produce is an important food safety practice, experts note that it may not completely remove Cyclospora, making it especially important to stay informed if officials announce recalls or identify the outbreak’s source.

Investigation Continues

Public health officials continue interviewing patients and analyzing food distribution records in an effort to determine exactly where the parasite originated.

Until a source is identified, consumers are encouraged to remain vigilant, practice safe food handling, and monitor updates from local health departments and the CDC.

As investigators gather more information, officials expect additional details—including whether a specific produce item is responsible—to emerge in the coming weeks.

This is a developing story and will be updated as new information becomes available.

Daniel Mayer, CC BY-SA 3.0, via Wikimedia Commons

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