A parasitic outbreak is spreading across the United States and accelerating. The CDC has confirmed 145 cases of cyclosporiasis across 17 states since May, and Michigan is reporting a separate surge of more than 300 cases in just 11 days, in a state that typically sees 50 cases in an entire year. No food source has been identified and no recall has been issued.
What Is Cyclosporiasis
Cyclosporiasis is an intestinal infection caused by Cyclospora cayetanensis, a microscopic parasite. It is not transmitted person to person. People get infected by consuming food or water contaminated with the parasite's oocysts (eggs).
In the United States, past outbreaks have been repeatedly linked to imported fresh produce including cilantro, basil, raspberries, snow peas, and mesclun lettuce. The summer timing is consistent with peak Cyclospora season, when contaminated produce from growing regions in Mexico and Central America enters the US supply chain.
How Many Cases and Where
National CDC data (May 1 through June 16, 2026):
145 confirmed cases across 17 states. States with reported cases include Massachusetts, Florida, Indiana, Wisconsin, Ohio, Pennsylvania, North Carolina, Virginia, Tennessee, Texas, Georgia, Colorado, Illinois, New York, New Jersey, Connecticut, and Alaska.
Michigan (separate outbreak, ongoing):
More than 300 cases confirmed as of July 2, concentrated in seven counties: Monroe, Lenawee, Washtenaw, Wayne, Livingston, Shiawassee, and Jackson. State health officials describe this as a "large and growing outbreak." Michigan normally sees approximately 50 cyclosporiasis cases per year.
The combined case count exceeds 450 and is almost certainly an undercount, as cyclosporiasis requires specific stool testing that is not part of standard panels. Many cases go undiagnosed.
Symptoms
Symptoms typically begin 1 week after exposure and include:
- Watery diarrhea, sometimes described as explosive
- Frequent, sometimes urgent bowel movements
- Loss of appetite and weight loss
- Nausea and fatigue
- Stomach cramps and bloating
- Low-grade fever
Unlike norovirus, which typically resolves in 24 to 72 hours, cyclosporiasis symptoms can last weeks to months if untreated. The illness responds well to a specific antibiotic (trimethoprim-sulfamethoxazole). Standard diarrhea treatments do not address the parasite.
Of the 145 nationally reported cases, 20 people were hospitalized. No deaths have been reported. Patients ranged in age from 5 to 86, with a median age of 42.
No Source Identified, No Recall Issued
As of July 4, 2026, investigators have not identified a common food source linking the cases. No food recall has been issued.
This is a known challenge with Cyclospora outbreaks. The parasite is difficult to detect during routine food safety testing, and by the time an outbreak is identified, the implicated produce has often already been consumed. Investigations typically take weeks or months to trace a source, if one is found at all.
Based on prior outbreak patterns, fresh herbs (particularly cilantro and basil), leafy greens, and fresh berries are the highest-risk categories. People in affected states should consider washing fresh produce thoroughly and, if they develop symptoms, specifically asking their doctor to test for Cyclospora since it is not detected by standard stool tests.
When to See a Doctor
See a doctor if you develop watery diarrhea lasting more than a few days, especially if combined with significant fatigue, loss of appetite, or weight loss. Tell your doctor you are concerned about Cyclospora so they can order the correct test. The illness is treatable with prescription antibiotics.
Track Current Cyclosporiasis Activity
Virus Watcher is monitoring cyclosporiasis outbreak reports across all affected states.
- Cyclosporiasis in Massachusetts
- Cyclosporiasis in Michigan
- Cyclosporiasis in Florida
- Cyclosporiasis in Indiana
- Cyclosporiasis in Wisconsin
- Cyclosporiasis in Ohio
- View all cyclosporiasis state tracking
Download the Virus Watcher app to receive alerts when outbreak activity is confirmed in your state.
