New York City has confirmed 273 cases of cyclosporiasis, a parasitic infection known for causing severe gastrointestinal distress, since May 1. This figure represents a significant increase compared to previous years, according to the NYC Health Department. For the entirety of 2026, the city had previously reported 301 cases.
The state of New York has also recorded an additional 125 cases since May 1, bringing the total for the state, excluding New York City, to 125. Health officials are collaborating with the Centers for Disease Control and Prevention (CDC), the Food and Drug Administration (FDA), and other health departments to identify the source and mode of transmission for these infections.
Cyclosporiasis is caused by the Cyclospora parasite and is typically contracted through the consumption of contaminated food or water, often during international travel to tropical regions. However, a troubling aspect of the recent outbreak is that many infected individuals in New York City reported no recent international travel, suggesting a potential source within the United States.
Symptoms of cyclosporiasis can include severe cramping, nausea, vomiting, fatigue, and watery, explosive diarrhea. While some infections resolve on their own, others may require hospitalization. The diagnosis can be challenging as it requires specialized laboratory tests not included in standard stool examinations, potentially leading to undiagnosed cases.
Health officials are advising the public to thoroughly wash all fruits and vegetables, and to cook produce when possible. Foods such as salad mixes, cilantro, and raspberries have been identified in past outbreaks as potential sources. The parasite requires one to two weeks outside the body to become infectious after passing through feces, making person-to-person transmission unlikely.
Michigan has reported the highest number of cases nationwide, with 681 cases, while Texas has reported 48. The parasite has been detected in at least 15 other states. Despite the increase, New York state officials noted that current numbers are comparable to this time in previous years, with 500 to 700 cases typically reported annually over the past two years.
Investigations are ongoing to identify any potential clusters or common sources of illness. While treatment is available, including a course of antibiotics, symptoms can persist for a month or longer if left untreated, potentially leading to dehydration, particularly in vulnerable populations such as the elderly, children, and immunocompromised individuals.