Domestically-acquired Cases of Cyclosporiasis — United States, May–August 2020

Last Updated JULY 30, 2020 5:00 PM EDT

While cyclosporiasis cases are reported year-round in the United States, cyclosporiasis acquired in the United States (i.e., “domestically acquired”, or cases of cyclosporiasis that are not associated with travel to a country that is considered endemic for Cyclospora) is most common during the spring and summer months. The exact timing and duration of U.S. cyclosporiasis seasons can vary, but reports tend to increase starting in May. In previous years the reported number of cases peaked between June and July, although activity can last as late as September. The overall health impact (e.g., number of infections or hospitalizations) and the number of identified clusters of cases (i.e., cases that can be linked to a common exposure) also vary from season to season.

CDC, along with state and federal health and regulatory officials, monitor this increase of cyclosporiasis in the United States in the spring and summer months to try to detect outbreaks linked to a common food source. However, many cases of cyclosporiasis cannot be directly linked to an outbreak, in part because of the lack of validated laboratory methods needed to link cases of Cyclospora infection. Officials use questionnaires to interview sick people to determine what they ate in the 14-day period before illness onset. If a commonality is found, CDC and partners work quickly to determine if contaminated product is still available in stores or in peoples’ homes and issue advisories.

At a Glance
  • States reporting cases: 28
  • Deaths: 0
  • Hospitalizations: 49

Latest Information

  • The number of reported cases of domestically acquired cyclosporiasis has increased from the previous month and has been elevated since May 1, 2020.
  • As of July 29, 2020, 779 laboratory-confirmed cases of cyclosporiasis have been reported to CDC by 28 states and New York City since May 1, 2020 in people who had no history of international travel during the 14-day period before illness onset.
    • The median illness onset date was June 8, 2020 (range: May 1–July 20, 2020).
    • At least 49 people have been hospitalized; no deaths have been reported.
July 29, 2020

Geographic Distribution of Reported Cases of Domestically Acquired Cyclosporiasis—Since May 1, 2020



*Data are current as of 7/29/2020 (1:00pm EDT).  States/jurisdictions highlighted on the map have each reported at least one case.  Data are preliminary and subject to change.  For questions related to the number of cases reported in each state, please contact that state’s health department.

Previous Updates

Page last reviewed: July 30, 2020