More than 400 sick as CDC searches for the source of a mystery outbreak

The Centers for Disease Control and Prevention is investigating a multistate Cyclospora outbreak that has infected more than 400 people across four states, with investigators still unable to identify the contaminated food source. The CDC estimates the actual case count exceeds reported numbers significantly.

Cyclospora cayetanensis, a parasitic pathogen, causes cyclosporiasis, an intestinal infection producing severe diarrhea, fatigue, and abdominal cramping that typically lasts one to two weeks without treatment. The parasite spreads through contaminated water or food, particularly fresh produce like berries, lettuce, and herbs.

The outbreak spans multiple states, complicating trace-back efforts. CDC epidemiologists are conducting interviews with patients to identify common food exposures and are working with state health departments and the FDA to narrow down the source. Initial investigations have not yet pinpointed a specific contaminated product or supplier.

The agency urges anyone experiencing symptoms consistent with cyclosporiasis to seek medical attention immediately. Diagnosis requires specific stool testing, as Cyclospora infections often go unrecognized without targeted lab work. Healthcare providers must request this test specifically, as standard stool samples may miss the parasite.

Treatment typically involves trimethoprim-sulfamethoxazole antibiotics, though other regimens exist for patients with allergies. Without treatment, symptoms can persist for weeks or months, leading to significant dehydration and nutritional loss in severe cases.

This outbreak underscores ongoing challenges in fresh produce safety. Cyclospora outbreaks have recurred annually in North America for decades, often linked to imported berries and vegetables. The CDC's inability to quickly identify the source reflects the complexity of modern food supply chains, where produce can originate from multiple suppliers and countries before reaching consumers.

Public health officials recommend thorough washing of fresh produce and cooking foods to