Cyclosporiasis Outbreak Spreads: What to Know About US Cases

Health officials across the United States are currently monitoring an uptick in cases of cyclosporiasis, a gastrointestinal illness caused by the microscopic parasite Cyclospora cayetanensis. Recent reports from public health agencies, including those in California, have prompted renewed warnings from the Centers for Disease Control and Prevention (CDC) regarding food safety and hygiene practices.

Cyclosporiasis is an intestinal infection that individuals typically contract by consuming food or water contaminated with the parasite. Unlike some other foodborne illnesses that spread through person-to-person contact, this parasite requires time—usually days or weeks—to become infectious after being passed in a bowel movement. Consequently, the infection is rarely transmitted directly between people.

Symptoms of the illness can be severe and often appear about a week after a person consumes contaminated items. The most common sign is watery diarrhea, which is frequently accompanied by a loss of appetite, weight loss, stomach cramps, bloating, increased gas, nausea, and fatigue. In some instances, infected individuals may also experience vomiting or low-grade fever. If left untreated, the symptoms can persist for several weeks or even months, often coming and going in waves.

Public health experts note that the parasite is most commonly associated with imported fresh produce. Historically, outbreaks in the United States have been linked to a variety of fresh items, including cilantro, basil, lettuce, raspberries, and snow peas. The parasite thrives in warm, tropical climates, making it a recurring issue for nations that export fresh produce to the U.S. during certain times of the year.

The current investigation involves federal and state health departments working in tandem to trace the source of the recent clusters. Identifying the specific food item responsible for an outbreak can be a complex and time-consuming process, as it involves detailed interviews with patients to determine exactly what they ate in the days leading up to their illness. When multiple people report eating the same specific brand or type of vegetable or fruit, investigators can begin to narrow down the supply chain to locate the source of contamination.

Prevention remains the best defense against cyclosporiasis. While washing produce is always recommended, health officials caution that it does not guarantee the removal of the parasite, as Cyclospora can be difficult to dislodge from the surfaces of fresh leaves and berries. Thorough cooking is the most effective way to kill the parasite. However, for those who prefer fresh salads and raw vegetables, the CDC recommends buying from reputable sources and staying informed about any active food safety recalls issued by the U.S. Food and Drug Administration (FDA).

If you believe you have symptoms of cyclosporiasis, it is important to contact a medical provider. Doctors typically diagnose the infection through stool sample tests. Once confirmed, the illness is treated with a specific course of antibiotics, usually a combination of trimethoprim and sulfamethoxazole. Most patients recover well with appropriate medical intervention, though those with weakened immune systems may require closer monitoring.

As the investigation continues, state health departments are urging residents to practice good hand hygiene and to report suspected foodborne illnesses to their local health clinics. Public health officials emphasize that while these outbreaks occur periodically, awareness and prompt medical care are essential to managing the spread and ensuring the well-being of the community.

Consult a healthcare professional.