Cyclospora: The Microscopic Parasite Causing Explosive Diarrhea in Pennsylvania and New Jersey
In recent weeks, health officials have been on high alert due to an outbreak of cyclosporiasis, an intestinal illness caused by the microscopic parasite Cyclospora cayetanensis. This parasite, which is typically found in tropical and subtropical regions, has been linked to cases of explosive diarrhea in Pennsylvania and New Jersey, with a cluster of cases reported in Southeastern Pennsylvania.
The Centers for Disease Control and Prevention (CDC) has recorded 145 reported cases of cyclosporiasis between May 1 and June 16, with a significant number of cases also reported in Michigan and Ohio. The Pennsylvania Department of Health has recorded 28 cases in 2026, with 14 occurring in Southeastern Pennsylvania, a slight increase from the 40 cases recorded in 2025 and the 87 cases recorded in 2024.
What makes this outbreak particularly concerning is the potential for severe symptoms, especially in immunocompromised individuals. The main symptom of cyclosporiasis is watery and sometimes explosive diarrhea, along with bloating, cramps, fatigue, increased gas, and a loss of appetite. Less common symptoms include body aches, a low-grade fever, and vomiting, which can last anywhere from a few days to a month or longer if left untreated.
Diagnosing cyclosporiasis can be challenging, as the parasite is not easy to detect. Doctors often rely on multiple stool samples to confirm a diagnosis. Once diagnosed, some healthcare providers may prescribe antibiotics, but the CDC notes that most people with healthy immune systems will recover without treatment. However, immunocompromised individuals are at risk of more severe or prolonged illness.
The source of the contamination remains unclear, but the CDC suspects that it is linked to imported produce, such as basil, cilantro, raspberries, and snow peas. The parasite can survive in contaminated food and water, and the CDC recommends avoiding feces-contaminated food or water. However, routine disinfecting is unlikely to kill the parasite, making it crucial to practice safe food preparation techniques.
In Pennsylvania, the CDC and the FDA advise washing produce before cooking, cutting, or eating, and washing hands with soap and water before and after handling raw fruits and vegetables. These steps can significantly reduce the risk of ingesting the parasite. Despite the current wave of cases, the CDC does not believe it is a single, multistate outbreak, and health officials continue to monitor the situation closely.
As an expert commentator, I find this outbreak fascinating for several reasons. Firstly, the fact that a microscopic parasite can cause such severe symptoms highlights the importance of proper food safety practices. Secondly, the rise in cases during the spring and summer months suggests a potential link to seasonal changes in food production and consumption. Finally, the challenge of diagnosing cyclosporiasis underscores the need for improved detection methods and public health surveillance systems.
In my opinion, this outbreak serves as a reminder of the ongoing threat of foodborne illnesses and the importance of public health preparedness. As we continue to navigate the complexities of global food supply chains, it is crucial to invest in research and development to better understand and prevent these types of outbreaks. By doing so, we can ensure the safety and well-being of our communities and reduce the impact of these illnesses on vulnerable populations.
