Cyclosporiasis Illnesses in the United States, 2023


OCTOBER 26, 2023

CDC, along with state and federal health and regulatory officials, monitor cases of cyclosporiasis in the United States to detect outbreaks linked to a common food source. Cyclosporiasis, caused by the parasite Cyclospora cayetanensis, causes diarrhea, loss of appetite, and cramping. Cyclosporiasis cases are reported year-round in the United States, with increases in case counts seen during the spring and summer months. This year, CDC began to receive reports of cases in April.

Fast Facts

  • Illnesses: 2,272
  • Hospitalizations: 186
  • Deaths: 0
  • States reporting cases: 40
  • Investigation status: Closed
  • If you have symptoms of cyclosporiasis, see your healthcare provider.
    They can test and treat you for cyclosporiasis.

2023 Cases:

Final Update

As of October 24, 2023, 41 jurisdictions, including 40 states and New York City, have reported a total of 2,272 laboratory-confirmed cases of cyclosporiasis. These individuals had not traveled outside of the United States during the 14 days before they got sick. This is an increase of 315 cases since the last update on August 31, 2023.

Sick people ranged in age from 2 to 96 years, with a median age of 51, and 57% were female. The median illness onset date was June 24, 2023 (range: April 1 to August 31). Of 2,242 people with information available, 186 have been hospitalized. Zero deaths have been reported.

Local, state, and federal (CDC, FDA) public health authorities investigated multiple potential clusters of cases during 2023. The total case count (2,272) included the clusters that were under investigation by the FDA.

Location of 2023 Cases

This map shows where the 2,272 people with cyclosporiasis acquired in the U.S. during April 1 to August 31, 2023, lived. Cyclosporiasis cases may not be limited to these states with known cases. The true number of people sick with cyclosporiasis was likely higher than the number reported. This is because some people recover without medical care and are not tested for Cyclospora.

*  These data include case data reported directly to the Cyclospora surveillance program at CDC. Case counts may not match exactly with what is listed in the Nationally Notifiable Diseases Surveillance System tables. New York State includes case reports from New York City. In Pennsylvania, cases are reported voluntarily. Data are preliminary and subject to change. For questions related to the number of cases reported in each state, contact that state’s health department.

Previous Updates