Cyclospora Outbreak 2026: What You Need to Know About the Parasite Sickening Hundreds Across the US

Hundreds of Cyclospora Infections Reported Across Multiple States

A significant outbreak of cyclosporiasis, caused by the microscopic parasite Cyclospora cayetanensis, is sweeping across the United States in what health officials are describing as one of the most notable foodborne illness events of the summer. As of early July 2026, over 680 cases have been confirmed in Michigan alone, with additional cases reported in at least 17 other states including New York, Illinois, Texas, and North Carolina.

The U.S. Centers for Disease Control and Prevention (CDC) is actively monitoring the situation in coordination with the Food and Drug Administration (FDA) and state health departments. While no single contaminated food source has been identified across all cases, investigators are working to trace clusters of infections to their origin.

What Is Cyclospora?

Cyclospora cayetanensis is a microscopic, single-celled parasite that infects the small intestine and causes a diarrheal illness known as cyclosporiasis. The parasite is transmitted through the fecal-oral route, meaning people become infected by ingesting food or water contaminated with feces containing the parasite.

Unlike many other foodborne pathogens, Cyclospora requires time outside the body — typically one to two weeks — before it becomes infectious. This means person-to-person transmission is extremely unlikely, and infections almost always stem from contaminated food or water consumed days to weeks earlier.

In the United States, Cyclospora outbreaks have historically been linked to fresh produce items such as:

• Basil and cilantro
• Raspberries and blackberries
• Snow peas and sugar snap peas
• Bagged salad mixes and romaine lettuce

The parasite thrives in tropical and subtropical regions but is increasingly detected in domestically grown and imported produce across the United States.

Current Outbreak Statistics

The CDC reports that as of June 16, 2026, at least 145 domestically acquired cases had been recorded across 17 states. However, these figures do not include the explosive surge of cases reported in Michigan in late June and early July, where infections jumped from 170 to over 681 in a matter of days across at least eight counties: Monroe, Lenawee, Washtenaw, Wayne, Shiawassee, Jackson, Oakland, and Livingston.

Michigan typically sees only about 50 cases of cyclosporiasis in an entire year, making this year’s spike particularly alarming to state health officials.

In North Carolina, at least 110 infections have been reported, with other significant clusters in New York, Illinois, and Texas. Nationwide, at least 20 people have been hospitalized. No deaths have been reported to date.

Affected individuals range in age from 5 to 86, with a median age of 42. The majority of cases (61%) are female. Illness onset dates span from May 1 through early June, but the CDC cautions that the true number of infections is likely higher than what has been reported, as many people with mild symptoms may not seek medical care or testing.

Recognizing the Symptoms

Symptoms of cyclosporiasis typically appear between two and 14 days after ingesting the parasite. The hallmark symptom is severe, watery diarrhea often described by patients as explosive and debilitating. Additional symptoms include:

• Loss of appetite and significant weight loss
• Stomach cramps and bloating
• Nausea and vomiting
• Low-grade fever
• Fatigue and general malaise

One of the most challenging aspects of cyclosporiasis is its duration. The illness can last from a few days to more than a month, and symptoms frequently relapse — returning after appearing to resolve. This relapsing pattern is a hallmark of the infection and can lead to prolonged suffering and dehydration if not properly managed.

Treatment Options

Cyclosporiasis is treatable. The standard recommended treatment is a combination antibiotic, typically trimethoprim-sulfamethoxazole (TMP-SMX), also known as Bactrim or Septra. This medication is highly effective at reducing the duration of symptoms and clearing the parasite from the body.

For individuals with sulfa allergies or those who cannot take TMP-SMX, alternative treatment options are available but should be discussed with a healthcare provider. Most people with healthy immune systems will recover from cyclosporiasis without antibiotic treatment, though recovery can be prolonged and uncomfortable.

Important: Anti-diarrheal medications alone are not recommended for cyclosporiasis, as they may prolong the infection by preventing the body from clearing the parasite.

Prevention: How to Protect Yourself and Your Family

Because Cyclospora contaminates fresh produce that is often eaten raw, complete prevention can be challenging. However, the following steps can significantly reduce your risk:

• Wash all fresh produce thoroughly under running water before eating, cutting, or cooking. Scrubbing firm-skinned fruits and vegetables with a clean brush can help remove surface contamination.
• Practice good hand hygiene — wash hands with soap and warm water before and after handling raw produce, after using the bathroom, and before eating.
• Cook produce when possible — heating food to an internal temperature of at least 63°C (145°F) kills the Cyclospora parasite.
• Be aware of outbreak notices — follow CDC and FDA updates during the May-to-August cyclosporiasis season.
• Avoid eating raw produce associated with current outbreaks when health advisories are active.

Who Is at Greatest Risk?

While anyone can contract cyclosporiasis, certain populations are at higher risk for severe or prolonged illness:

• Infants and young children
• Pregnant women
• Older adults
• Individuals with weakened immune systems (including those with HIV/AIDS, organ transplant recipients, or those undergoing chemotherapy)
• Travelers to tropical and subtropical regions where the parasite is more common

Frequently Asked Questions

Can Cyclospora be spread from person to person?

No. Unlike many other gastrointestinal pathogens, Cyclospora requires time outside the body (one to two weeks) to become infectious. Direct person-to-person transmission is highly unlikely.

How is cyclosporiasis diagnosed?

Diagnosis requires a specialized laboratory test called a stool ova and parasite (O&P) examination with specific staining for Cyclospora. Standard stool cultures do not detect this parasite, so patients must specifically request testing if Cyclospora is suspected.

Can I get Cyclospora more than once?

Yes. Infection with Cyclospora does not provide long-term immunity. People can be reinfected if they ingest the parasite again.

Is there a vaccine for Cyclospora?

No, there is currently no vaccine available for Cyclospora cayetanensis. Prevention relies entirely on food safety and hygiene practices.

Should I avoid all fresh produce?

No. Fresh produce remains an important part of a healthy diet. During outbreak seasons, simply follow food safety guidelines, wash produce thoroughly, and stay informed about current recalls and advisories from the CDC and FDA.

How long does cyclosporiasis last without treatment?

Without antibiotic treatment, symptoms may last from a few days to more than a month. The illness often follows a relapsing pattern, with symptoms returning after appearing to resolve.

The Bottom Line

The Cyclospora outbreak of 2026 is a serious public health concern, particularly in Michigan, North Carolina, and other states seeing significant case numbers. While the infection is rarely life-threatening, it can cause prolonged, debilitating illness. Anyone experiencing persistent watery diarrhea, especially with accompanying stomach cramps or nausea, should contact their healthcare provider and specifically ask about cyclosporiasis testing.

As the CDC and FDA continue their investigations, staying informed and practicing thorough food hygiene remain the best defenses. Health Professional Radio will continue monitoring this outbreak and provide updates as new information becomes available.