Cilantro has been identified as a potential source. FDA has issued an import alert for cilantro imported from Puebla, Mexico. A potential scenario is that the cilantro becomes contaminated from contaminated water used for irrigation or washing, or from contaminated workers handling the fresh product. The fresh cilantro is then added to flavor items such as fresh salsa and consumed, so there are no processing steps that would eliminate the parasite.
CDC Outbreak Investigation
http://www.cdc.gov/parasites/cyclosporiasis/outbreaks/2015/index.html
Cyclosporiasis Outbreak Investigations — United States, 2015
Last Updated July 31, 2015 1:00 PM EDT
UPDATES WILL BE PROVIDED WHEN MORE INFORMATION IS AVAILABLE
CDC and federal, state, and local public health partners are investigating an increase in reported cases of Cyclospora infection.
Highlights
Read the related statement from the U.S. Food and Drug Administration
Read the Advice to Consumers
Cyclospora cayetanensis is a single-celled parasite that causes an intestinal infection called cyclosporiasis.
As of July 30, 2015 (11am EDT), CDC had been notified of 358 ill persons with confirmed Cyclospora infection from 26 states in 2015.
Most (199; 56%) ill persons experienced onset of illness on or after May 1, 2015 and did not report international travel prior to symptom onset.