Cyclosporiasis Illnesses in the United States, 2023

Last Updated AUGUST 31, 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: 1957
  • Hospitalizations: 153
  • Deaths: 0
  • States reporting cases: 39
  • Investigation status: Active (first posted on May 25, 2023)
  • If you have symptoms of cyclosporiasis, see your healthcare provider.
    They can test and treat you for cyclosporiasis.

2023 Cases:

As of August 29, 2023, 40 jurisdictions, including 39 states and New York City, have reported a total of 1,957 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 894 cases since the last update on July 27, 2023.

Sick people range in age from 2 to 96 years, with a median age of 50, and 58% are female. The median illness onset date is June 23, 2023 (range: April 1 to August 22). Of 1,932 people with information available, 153 have been hospitalized. Zero deaths have been reported.

Local, state, and federal (CDC, FDA) public health authorities are investigating multiple potential clusters of cases. The total case count (1,957) includes the clusters under investigation by the FDA. Investigations to identify potential sources are ongoing.

Location of 2013 Cases

This map shows where the 1,957 people with cyclosporiasis acquired in the U.S. since April 1, 2023, lived. Cyclosporiasis cases may not be limited to these states with known cases. The true number of people sick with cyclosporiasis is likely higher than the number reported. This is because some people recover without medical care and are not tested for Cyclospora.

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