Domestically Acquired Cases of Cyclosporiasis — United States, May–August 2019

Last Updated AUGUST 29, 2019 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.

Latest Information

  • The number of reported cases of domestically acquired cyclosporiasis has increased from the previous month and remains elevated in the United States since May 1, 2019.
  • As of August 28, 2019, 1,696 laboratory-confirmed cases of cyclosporiasis were reported to CDC by 33 states, District of Columbia and New York City in people who became ill since May 1, 2019 and who had no history of international travel during the 14-day period before illness onset.
    • The median illness onset date was June 29, 2019 (range: May 1–August 13, 2019).
    • At least 92 people were hospitalized; no deaths were reported.
    • At this time, multiple clusters of cases associated with different restaurants or events are being investigated by state public health authorities, CDC, and FDA.
    • One multistate outbreak of Cyclospora infections has been linked to fresh basil imported from Siga Logistics de RL de CV of Morelos, Mexico . It is unknown at this time if other reported cases of Cyclospora infection in the United States this season are linked to fresh basil. This investigation is ongoing.
    • Many cases of cyclosporiasis could not be directly linked to an outbreak, in part because of the lack of validated molecular typing tools for C. cayetanensis.
At a Glance
  • States reporting cases: 33
  • Deaths: 0
  • Hospitalizations: 92
Case Count Map

Geographic Distribution of Reported Cases of Domestically Acquired Cyclosporiasis with Illness Onset on or after May 1, 2019

outbreak map

Click map to view case count map.

Previous Updates

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.

Latest Information

  • The number of reported cases of domestically acquired cyclosporiasis has increased from the previous month and remains elevated in the United States since May 1, 2019.
  • As of July 23, 2019, 580 laboratory-confirmed cases of cyclosporiasis were reported to CDC by 30 states, District of Columbia and New York City in people who became ill since May 1, 2019 and who had no history of international travel during the 14-day period before illness onset.
    • The median illness onset date was June 24, 2019 (range: May 3–July 13, 2019).
    • At least 38 people were hospitalized; no deaths were reported.
    • At this time, multiple clusters of cases associated with different restaurants or events are being investigated by state public health authorities, CDC, and FDA.
    • One multistate outbreak of Cyclospora infections has been linked to fresh basil imported from Siga Logistics de RL de CV of Morelos, Mexico . It is unknown at this time if other reported cases of Cyclospora infection in the United States this season are linked to fresh basil. This investigation is ongoing.
    • Many cases of cyclosporiasis could not be directly linked to an outbreak, in part because of the lack of validated molecular typing tools for C. cayetanensis.

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.

Latest Information

  • The number of reported cases of domestically acquired cyclosporiasis has increased from the previous month and remains elevated in the United States since May 1, 2019.
  • As of June 24, 2019, 23 laboratory-confirmed cases of cyclosporiasis were reported to CDC by 10 states and New York City in people who became ill since May 1, 2019 and who had no history of international travel during the 14-day period before illness onset.
    • The median illness onset date was May 13, 2019 (range: May 3–June 10, 2019).
    • At least two people were hospitalized; no deaths were reported.
    • At this time, no specific vehicle of interest has been identified, and investigations to identify a potential source (or sources) of infection are ongoing. It is not currently known whether reported cases are related to each other or represent one or more outbreaks.

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.

Latest Information

  • As of May 29, 2019, 2 laboratory-confirmed cases of cyclosporiasis were reported to CDC by two states in people who became ill since May 1, 2019 and who had no history of international travel during the 14-day period before illness onset.
    • The median illness onset date was May 5, 2019 (range: May 4–May 6, 2019).
    • No hospitalizations or deaths have been reported.
    • At this time, no specific vehicle of interest has been identified, and investigations to identify a potential source (or sources) of infection are ongoing. It is not currently known whether reported cases are related to each other or represent one or more outbreaks.

 

Page last reviewed: August 29, 2019