Investigation of an Outbreak of Cyclosporiasis in the United States
On June 28, 2013, CDC was notified of 2 laboratory-confirmed cases of Cyclospora infection in Iowa residents who had become ill in June and did not have a history of international travel during the 14 days before the onset of illness. Since that date, CDC has been collaborating with public health officials in multiple states and the US Food and Drug Administration (FDA) to investigate an outbreak of cyclosporiasis. Preliminary details of the ongoing investigation are highlighted below.
On June 28, 2013, CDC was notified of 2 laboratory-confirmed cases of Cyclospora infection in Iowa residents who had become ill in June and did not have a history of international travel during the 14 days before the onset of illness. CDC has been collaborating with public health officials in several states and with regulatory officials at the FDA to investigate an outbreak of Cyclospora infection.
CDC's independent analyses of data from the epidemiologic investigations in Iowa and Nebraska confirmed an association between consuming salad and being ill with cyclosporiasis during June and July 2013 in those two states. This salad was determined to be a pre-packaged salad mix.
On August 2, 2013, CDC received results of a traceback investigation from FDA. The traceback investigation conducted by FDA identified Taylor Farms de Mexico, S. de R.L. de C.V., a processor of foodservice salads, as the source of the pre-packaged salad mix identified in the cyclosporiasis outbreak in Iowa and Nebraska.
Investigation of the Outbreak
The national investigation is ongoing and collaborative. CDC's initial efforts included providing scientific consultation to Iowa and Nebraska during early stages of the outbreak. By July 16, 2013, as cases were reported from other states, CDC began leading a multistate epidemiologic investigation, including coordination and analysis of data from state and local health departments and laboratory confirmation of cases, including via DPDx telediagnosis. During this and other multistate foodborne disease outbreaks, CDC has served as the lead coordinator among public health partners to help define the size and extent of the outbreaks and to identify the cause(s).
CDC has dedicated a team of epidemiologists, laboratory scientists, statisticians, and communicators to the work on the outbreak full time, with additional staff assisting. On July 24, 2013, CDC initiated an Epi-Aid, and has deployed an Epidemic Intelligence Service (EIS) Officer and a Public Health Prevention Service (PHPS) fellow to Texas to assist with the epidemiologic investigation of cyclosporiasis cases in that state.
Previous investigations have implicated various imported fresh produce items. At this stage of the investigation it is unclear if transmission is still occurring nationally and if all of the reported cases are part of the same outbreak.
CDC and its public health partners are vigorously working to determine if the conclusion reached in Iowa and Nebraska helps explain the increased cases of cyclosporiasis in other states. We will update the public on the progress of the national investigation as information becomes available.