The United States is experiencing a significant outbreak of cyclosporiasis, a parasitic foodborne illness, with over 1,600 confirmed cases and more than 5,100 additional cases under investigation. The Centers for Disease Control and Prevention (CDC) has been tracking the rise in infections, which have particularly impacted Midwestern states.
Cyclosporiasis is caused by the parasite Cyclospora cayetanensis, which spreads through contaminated food or water. Symptoms typically begin about a week after exposure, though the incubation period can range from two days to two weeks. Initial symptoms can mimic those of a common viral stomach bug, including diarrhea, nausea, abdominal pain, and loss of appetite. However, cyclosporiasis infections tend to be more severe and last longer than typical gastrointestinal viruses.
Dr. Kenneth Perry, an emergency physician, noted that while routine stomach bugs often resolve within 24 to 48 hours, cyclosporiasis can result in prolonged bouts of severe, watery, and foul-smelling diarrhea, along with significant cramping and fatigue.
Diagnosing cyclosporiasis can be challenging because it is not routinely included in standard stool testing panels. Healthcare providers must specifically request a Cyclospora test. According to the CDC, diagnosis is made by examining stool specimens, and multiple samples collected on different days may be necessary for detection, as even symptomatic individuals may not consistently shed the parasite.
If symptoms are strongly suggestive of cyclosporiasis despite an initial negative test, repeat screening may be required. Primary care physicians are often the best point of contact for patients seeking a diagnosis, as emergency departments typically do not screen for this specific parasite. Emergency departments are appropriate for treating secondary symptoms like dehydration.
Patients experiencing diarrhea lasting more than two to three days, or symptoms that worsen or are accompanied by signs of dehydration, should consult a primary care physician. Unlike most viral stomach bugs, cyclosporiasis is treatable with prescription antibiotics, with trimethoprim-sulfamethoxazole being the standard recommended treatment by the CDC. Individuals who cannot take sulfa drugs should discuss alternative options with their healthcare provider. Health officials are working to identify the source of the current outbreak.