Health officials are tracking a rise in cyclosporiasis infections, a parasitic illness causing severe diarrhea, across at least 17 U.S. states since May 2026. The Centers for Disease Control and Prevention confirmed that Michigan alone has reported more than 170 cases since June 22, 2026, while investigations continue to identify the source of the infections.
The CDC is working alongside the Food and Drug Administration to determine what is causing the increase in cases. As of July 1, 2026, officials stated there is no evidence of a single, multi-state cyclospora outbreak linking all cases. At least 20 people have been hospitalized nationwide, but no deaths have been reported.
Main Developments in the Cyclosporiasis Investigation
Between May 1 and June 16, 2026, health authorities documented at least 145 cyclosporiasis cases across 17 U.S. states. New York has reported the highest number of cases, followed by Illinois and Texas. The infected individuals range in age from 5 to 86 years old.
Michigan has emerged as a significant hotspot in this health situation. The state typically identifies approximately 50 cases of cyclosporiasis per year. However, since June 22, 2026, more than 170 cases have been reported, concentrated in seven southeast Michigan counties: Monroe, Lenawee, Washtenaw, Wayne, Livingston, Shiawassee and Jackson.
Health officials noted that none of the infected individuals in Michigan reported traveling internationally in the weeks prior to becoming ill. This suggests the infections originated from domestically sourced food products.
The CDC acknowledged that the true number of people sick with cyclosporiasis was likely higher than the number reported, as many cases may go undiagnosed or unreported.
What We Know So Far
Cyclosporiasis is caused by the Cyclospora cayetanensis parasite. The infection typically causes severe watery diarrhea, which health officials have described as potentially explosive in nature. The illness spreads through consuming food or water contaminated with the parasite.
The incubation period for cyclosporiasis ranges from 2 to 14 days after consuming contaminated food or water. Once the parasite exits the body, it takes 1 to 2 weeks to become infectious, meaning person-to-person transmission is not an immediate concern.
Past outbreaks of cyclosporiasis have been linked to various types of fresh produce. Previous investigations have identified basil, cilantro, raspberries, snow peas and romaine lettuce as sources of contamination. In 2022, a cluster of cases in Florida was attributed to a Caesar salad kit containing bagged romaine lettuce.
The year 2019 saw an unusually high number of cyclosporiasis infections in the United States, with 4,703 cases identified nationwide.
What Happens Next
The CDC and FDA continue their joint investigation to identify the specific food source or sources responsible for the current rise in cases. Health officials are conducting interviews with infected individuals to identify common foods consumed before illness onset.
No single multi-state outbreak has been confirmed linking all cases, which means different clusters may have different sources. Investigations are ongoing in multiple states simultaneously as officials work to trace the origin of infections.
Health authorities have not announced any product recalls related to the current cyclosporiasis cases. Officials continue gathering information to determine whether a specific food item is responsible.
Important Details About Cyclosporiasis Symptoms
People infected with Cyclospora cayetanensis typically experience watery diarrhea as the primary symptom. The diarrhea can be severe and frequent. Other common symptoms may include loss of appetite, weight loss, stomach cramps, bloating, increased gas, nausea and fatigue.
Some infected individuals may also experience low-grade fever and body aches. Symptoms can last from a few days to more than a month if left untreated. The illness can be treated with prescription antibiotics, making it important for anyone experiencing these symptoms to seek medical attention.
The infection is not spread directly from person to person because the parasite needs time outside the body to become infectious. This characteristic distinguishes cyclosporiasis from many other gastrointestinal illnesses.
Prevention and Food Safety Recommendations
While the specific source of the current infections has not been identified, health officials generally recommend thorough washing of all fresh produce before consumption. However, it is important to note that washing may not eliminate all parasites from contaminated produce.
Consumers should purchase produce from reputable sources and store fresh fruits and vegetables properly. Refrigerating produce at appropriate temperatures can help maintain food safety.
Anyone experiencing severe diarrhea lasting more than a few days should consult a healthcare provider. Individuals who believe they may have cyclosporiasis should mention their concerns to their doctor, as specific testing is required to diagnose the infection.
Geographic Spread of Cases
The 17 states with reported cases span various regions of the United States. New York leads in case numbers, with Illinois and Texas following. The specific number of cases in each state beyond Michigan has not been detailed by health officials.
The concentration of cases in southeast Michigan counties suggests a possible localized exposure source in that region. However, the presence of cases in multiple states indicates the situation extends beyond any single geographic area.
The age range of infected individuals, spanning from 5 to 86 years old, demonstrates that cyclosporiasis can affect people of all ages who consume contaminated food.
Frequently Asked Questions
What causes cyclosporiasis?
Cyclosporiasis is caused by the Cyclospora cayetanensis parasite, which spreads through contaminated food or water. Past outbreaks have been linked to fresh produce including basil, cilantro, raspberries, snow peas and romaine lettuce.
How long does it take to get sick after exposure?
The incubation period for cyclosporiasis is 2 to 14 days after consuming contaminated food or water. Symptoms may appear within this timeframe following exposure to the parasite.
Can cyclosporiasis spread from person to person?
Direct person-to-person transmission is unlikely because the parasite requires 1 to 2 weeks outside the body to become infectious. The infection spreads primarily through contaminated food or water consumption.
What are the main symptoms of cyclosporiasis?
The primary symptom is severe watery diarrhea. Other symptoms may include stomach cramps, bloating, nausea, fatigue, loss of appetite and weight loss. Some people experience low-grade fever.
Is cyclosporiasis treatable?
Cyclosporiasis can be treated with prescription antibiotics. Anyone experiencing severe or prolonged diarrhea should seek medical attention for proper diagnosis and treatment.
Health officials urge the public to remain vigilant about food safety practices and to seek medical care if experiencing symptoms consistent with cyclosporiasis. The CDC continues to monitor the situation and update the public as the investigation progresses across affected states.
