The cdc parasite outbreak remains under active investigation as federal health officials continue tracking a multistate outbreak of cyclosporiasis linked to the microscopic parasite Cyclospora cayetanensis. As of the latest confirmed update, 145 domestically acquired illnesses have been reported across 17 states, resulting in 20 hospitalizations. No deaths have been confirmed, and investigators have not yet identified a single food source responsible for the outbreak.
What Is the Current CDC Parasite Outbreak?
The current outbreak involves cyclosporiasis, an intestinal illness caused by the parasite Cyclospora cayetanensis. The Centers for Disease Control and Prevention (CDC), together with the U.S. Food and Drug Administration (FDA) and state health departments, is investigating multiple clusters of illnesses reported during the 2026 summer season.
Unlike many previous Cyclospora infections that were linked to international travel, every confirmed patient in this investigation became sick after eating food in the United States. None reported recent international travel before symptoms began. This finding has led investigators to focus on a domestically distributed food product, although the exact source remains unknown.
Latest Confirmed Numbers
| Category | Latest Confirmed Update |
|---|---|
| Confirmed U.S. illnesses | 145 |
| States affected | 17 |
| Hospitalizations | 20 |
| Deaths | 0 |
| Illness onset period | May 1–June 16, 2026 |
| Food source identified | No |
States Reporting Cases
Health officials have confirmed illnesses in 17 states. New York currently has the largest number of reported cases, followed by Illinois and Texas. Additional confirmed cases have been reported in:
- Alaska
- Colorado
- Connecticut
- Florida
- Georgia
- Louisiana
- Massachusetts
- New Jersey
- North Carolina
- Ohio
- Pennsylvania
- Tennessee
- Virginia
- Wisconsin
Officials continue reviewing new reports, so the number of affected states and total cases may change as additional laboratory testing is completed.
Understanding Cyclospora
Cyclospora is a microscopic parasite that infects the small intestine and causes an illness known as cyclosporiasis.
People become infected after consuming food or water contaminated with infectious Cyclospora parasites. Unlike viruses such as norovirus, Cyclospora does not usually spread directly from one person to another because the parasite must mature outside the human body before becoming infectious.
Fresh fruits, vegetables, and herbs have been linked to previous U.S. outbreaks, but investigators have not connected the current illnesses to any specific food item.
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Symptoms of Cyclosporiasis
Symptoms usually develop about one week after exposure, although they may begin sooner or later depending on the individual.
The most common symptoms include:
- Watery diarrhea
- Stomach cramps
- Loss of appetite
- Weight loss
- Nausea
- Fatigue
- Bloating
- Increased gas
- Urgent bowel movements
- Low-grade fever in some cases
Some people recover without medication, but symptoms may continue for several weeks or even longer if treatment is delayed. Illness can also return after temporary improvement.
Who Is Most at Risk?
Anyone who consumes contaminated food or water can become infected.
Certain groups may experience more severe illness, including:
- Older adults
- Young children
- People with weakened immune systems
- Organ transplant recipients
- Cancer patients receiving treatment
Prompt medical care helps reduce the risk of prolonged illness and dehydration.
How the Parasite Spreads
Cyclospora spreads through the consumption of food or water contaminated with human feces containing the parasite.
Because the parasite requires time outside the body before becoming infectious, direct person-to-person transmission is considered unlikely.
This is one reason investigators are concentrating on potential food sources rather than household transmission.
Why the Source Has Not Been Identified
Foodborne outbreak investigations often require weeks of detailed work.
Public health investigators interview patients, examine grocery purchases, review restaurant visits, analyze food distribution records, and compare laboratory findings.
Fresh produce presents unique challenges because:
- Products are consumed quickly.
- Many ingredients are mixed into prepared foods.
- Consumers may not remember every item they ate.
- Distribution networks often cover several states.
Until investigators identify a common link supported by strong evidence, no food recall will be issued.
How Doctors Diagnose the Illness
Healthcare providers usually diagnose cyclosporiasis by ordering specialized laboratory testing on stool samples.
Because the illness resembles several other gastrointestinal infections, laboratory confirmation helps ensure patients receive the correct treatment.
Early diagnosis also assists public health officials in identifying additional outbreak cases.
Treatment Options
Cyclosporiasis is generally treatable with prescription antibiotics.
The most commonly recommended treatment is trimethoprim-sulfamethoxazole (TMP-SMX).
Patients should also drink plenty of fluids to prevent dehydration caused by persistent diarrhea.
Anyone experiencing severe diarrhea, dehydration, or symptoms lasting several days should contact a healthcare provider.
Food Safety Tips During the Outbreak
Although investigators have not identified the contaminated product, basic food safety practices remain important.
Consumers should:
- Wash hands before preparing food.
- Rinse fruits and vegetables under running water.
- Refrigerate perishable foods promptly.
- Separate raw foods from ready-to-eat foods.
- Drink safe, clean water.
Washing produce reduces many food safety risks, although it may not completely eliminate Cyclospora from contaminated foods.
Why Cases Increase During Summer
Cyclosporiasis follows a seasonal pattern in the United States.
Most domestically acquired illnesses occur between May and August. This period coincides with greater availability of fresh produce and increased outdoor dining.
Public health officials increase surveillance each summer because outbreaks tend to occur during these warmer months.
How CDC Detects Foodborne Outbreaks
The CDC receives reports of laboratory-confirmed Cyclospora infections from state health departments throughout the country.
Scientists compare information from patients, including:
- Illness onset dates
- Geographic locations
- Foods consumed
- Laboratory testing results
When enough evidence connects multiple illnesses to a common source, investigators may recommend recalls or public health alerts.
At this time, officials have not identified a single contaminated food responsible for the current outbreak.
How This Outbreak Compares With Previous Years
Cyclospora outbreaks have occurred in the United States for many years, often involving contaminated fresh produce.
CDC surveillance recorded more than 1,100 domestically acquired cyclosporiasis cases during the 2025 season. The current investigation represents an early-season outbreak, and additional confirmed cases may be reported as laboratory testing continues.
Health officials note that reported case totals often underestimate the true number of illnesses because some infected people recover without seeking medical care or testing.
What Americans Should Know Right Now
The investigation remains active, and federal health officials continue working to identify the contaminated food responsible for the illnesses.
Anyone experiencing prolonged watery diarrhea, severe stomach cramps, dehydration, or other symptoms consistent with cyclosporiasis should seek medical evaluation.
Consumers do not need to avoid all fresh produce, but following safe food handling practices remains an important way to reduce the risk of foodborne illness while investigators continue tracing the outbreak.
What Happens Next?
The CDC and FDA are continuing interviews with patients, reviewing food distribution records, and conducting laboratory analysis to determine whether the illnesses share a common source.
If investigators identify the contaminated product, public health agencies are expected to issue additional guidance, including recalls or consumer advisories when appropriate.
Until then, the confirmed facts remain unchanged: 145 domestically acquired illnesses, 17 affected states, 20 hospitalizations, no reported deaths, and no confirmed food source.
Have questions about the CDC parasite outbreak or food safety? Share your thoughts in the comments and stay tuned for the latest verified updates.