The Centers for Disease Control and Prevention (CDC) is monitoring 145 cases of Cyclospora infection across 17 states as of June 16. This microscopic parasite, which causes explosive diarrhea, is considered a nationally notifiable disease, requiring healthcare providers to report cases to the federal government.
Patients range in age from 5 to 86 years, with 61% being women. Twenty individuals have been hospitalized, and no deaths have been reported. Health officials noted that these patients reported falling ill after consuming U.S.-based food and had not traveled within 14 days prior to becoming sick.
Dr. Bobbi Pritt, Chair of the Division of Clinical Microbiology at the Mayo Clinic, stated that the CDC's reported numbers likely represent only a portion of the actual infections. She explained that the actual count can be higher due to factors such as individuals with mild symptoms not seeking testing, cases where the correct diagnostic test is not ordered, or instances where cases are not reported.
Cyclospora infections are not detectable by a standard stool test and require an additional staining procedure, which is not typically part of routine testing, Pritt added. This can contribute to underreporting.
The majority of reported cases are concentrated in New York State, with 31 to 80 cases, followed by Texas and Illinois. Cases have also been identified in Alaska, Colorado, Connecticut, Florida, Georgia, Louisiana, Massachusetts, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, and Wisconsin.
Seasonal Occurrence
Case counts for Cyclospora typically increase during the spring and summer months, from May 1 through August 31, as the parasite thrives in tropical and subtropical conditions. The CDC reported the first case of the current season on May 13. This seasonal rise is attributed to increased consumption of fresh produce, such as salads, herbs, berries, and raw vegetables, which are more likely to harbor active parasites compared to cooked foods.
The CDC employs advanced molecular genetic analyses to examine the DNA of Cyclospora, helping to identify distinct strains and determine if they are linked to outbreaks in different states. This genetic typing aids in tracking the parasite and can help identify if multiple, unrelated sources of contaminated produce are entering the U.S. supply chain.
Transmission and Symptoms
Cyclospora is primarily transmitted through the consumption of contaminated food or water and is not spread from person to person. Symptoms typically appear within a week of consuming contaminated food or water. The hallmark symptom is prolonged watery diarrhea, often accompanied by abdominal cramping, bloating, nausea, fatigue, and loss of appetite. While the infection can resolve without antibiotics, untreated cases may persist for over a month, with fatigue sometimes lingering even after gastrointestinal symptoms subside.
In the past, imported fresh produce such as basil, cilantro, raspberries, and snow peas have been identified as sources of Cyclospora contamination. The parasite is shed in human stool and is believed to enter the food supply from soil in growing regions, particularly associated with poor hygiene and human fecal waste in food exported to the U.S.
Prevention
While the exact mechanisms of contamination are not fully understood, experts recommend preventative measures such as washing hands thoroughly with soap and water before and after handling raw fruits and vegetables. Produce should be washed under running water before consumption or preparation, even if labeled as pre-washed. Firm produce, like melons and cucumbers, should be scrubbed with a brush. However, chemical disinfection is unlikely to fully eliminate the parasite. Health officials emphasize that fresh produce remains a vital part of a healthy diet and encourage individuals to consult a healthcare provider if they develop prolonged watery diarrhea or other concerning symptoms.