More than 1,200 cases have been reported of cyclosporiasis alone in the state of Michigan, according to reports from ABC news. In addition, the infection has been detected in at least 17 states across America, according to the CDC. Here’s what to know about this infection that is more common in the summer months.
What Is Cyclosporiasis?
Cyclosporiasis is a food-borne illness that is caused by a parasitic infection. Most people get infected after drinking contaminated water or contaminated food that contains the parasite. Thus, it is not usually spread person to person.
In the United States, most outbreaks have been linked to fresh produce, and foods most commonly involved in prior outbreaks include lettuce, basil, cilantro, bagged salad mixes and raspberries. The causative food, whether or not it is produce, is currently not known in the outbreaks that have occurred across the United States.
Common Symptoms
Most patients develop symptoms about a week after getting exposed to contaminated food, but this can occur anywhere from two days to two weeks after exposure. Symptoms can be nonspecific but most commonly include nausea, bloating, cramping and profuse watery diarrhea.
Most infectious diseases that affect the gut typically result in diarrhea that lasts 2-4 days. However, with cyclosporiasis, diarrhea can last weeks and even months, differentiating this disease from the majority of other gastrointestinal illnesses. Thus, if experiencing diarrhea for more than 3 days, it is critical to be evaluated by a doctor to get treated, which consists of a 10-day course of antibiotics.
Who Is Most At Risk?
This parasitic infection can affect anyone, although some individuals are more at risk for infection and its complications, which mainly consists of dehydration from the large volume of fluids lost from diarrhea. Those individuals include children, the elderly, pregnant females, individuals with chronic medical conditions and those on chemotherapeutic drugs. These individuals have weakened immune systems so their bodies may not be able to fight off the infection as effectively as healthier adults with strong immune systems.
Why Does This Occur In Summer?
Cyclosporiasis remains most common between May and August because the parasite thrives in warmer, humid climates because it needs heat to mature before infecting humans. In addition, Americans tend to eat more produce in the summer and import more fruits and vegetables from other countries during this time, allowing cases of cyclosporiasis to potentially surge.
How Can You Protect Yourself?
The vast majority of cases can be prevented by simple measures. Washing hands thoroughly for 20 before preparing food, before eating and after using the bathroom can decrease your chances of eating and being exposed to contaminated food. In addition, if purchasing produce, washing and scrubbing the produce with water as well as refrigerating it as soon as returning home can reduce the growth of the parasite that causes cyclosporiasis.
Surveillance And Public Health
Of note, as of July 2025, the CDC’s Foodborne Diseases Active Surveillance Network no longer requires reporting for cyclosporiasis. Although healthcare providers and laboratories continue to report confirmed cases to state health departments, this could make it more challenging to get accurate counts on confirmed cases in the United States.
These outbreaks, particularly cyclosporiasis, remind us that our food supply is global. Food safety depends not only on sanitation, surveillance and outbreak investigations; but also staying informed on symptoms and how to stay protected.