Food Safety Magazine features an article on Cyclospora cayetanensis and the challenges it poses to the produce industry as the incidence has increased over the past decade.
Here is a summary of that article.
Here is a summary of that article.
- C. cayetanensis is a parasite that infects the small intestine, causing watery diarrhea with frequent, sometimes explosive, bowel movements. The organism is "transmitted when feces from an infected individual contaminates food or water; however, it is not transmitted directly from person to person because after being shed, the parasite needs time (estimated one to two weeks, at least) in the environment to become infective."
- While the organism is more commonly found in tropical and subtropical regions, "outbreaks of C. cayetanensis infections have been documented since the mid-1990s in the U.S., Canada, Europe, and Australia, and have been associated with the consumption of fresh produce, including raspberries, basil, mesclun, lettuce, snow peas, cilantro, and green onions." Note that these are produce items that are generally more delicate, and thus more difficult to thoroughly wash.
- Outbreak numbers of the past 3 years tend to be large. [data in report goes back to 2013]
2018
Salad Mix - 511 cases in 15 statesBasil - 16 cases in 2 statesVegetable trays - 250 cases in statesCilantro - 53 cases in 3 states
2019
Basil - 241 cases in 11 states
2020
Bagged salad - 701 cases in 14 states
- A huge challenge has been difficulty in determining clusters of cases that can be used to identify the source.
- "WGS [whole genome sequencing] is impractical for routine use in cyclosporiasis outbreak investigations for a number of reasons. One reason is that the C. cayetanensis genome is approximately tenfold larger than a bacterial genome; rarely is enough quality DNA obtained from clinical stool specimens or produce samples to sequence the entire parasite genome. Also, unlike bacterial pathogens, this parasite cannot be propagated in the laboratory." However, "FDA has developed multi-laboratory validated methodologies that detect intact oocysts of C. cayetanensis on food matrices such as basil, cilantro, and romaine lettuce, and in agricultural water."
- Identifying the specific food can be difficult. For one, there is generally a 14 day lag between consumption and symptoms. And then diagnosis can be difficult.
- Taking these two factors into account, coupled with the difficulty of finding the organism within the environment or the food, traceback is difficult.
- C. cayetanensis is resistant to most common disinfectants used in the food industry and, therefore, also poses a challenge across the food supply to prevent and eliminate contamination.
- FDA has been conducting increased surveillance of imported produce, especially herbs such as basil and cilantro. FDA has also sampled and tested domestically grown romaine for C. cayetanensis.
- "While additional prevention and control measures are being researched and developed, basic handwashing and hygiene remain critically important in preventing the spread of cyclosporiasis. FDA recently published the "Cyclospora Prevention, Response, and Research Action Plan," which outlines actions necessary to improve prevention, enhance response activities, and fill knowledge gaps to help prevent Cyclospora contamination of foods and prepare for responding to future outbreaks."
Food Safety Magazine (April / May 2022)
https://digitaledition.food-safety.com/april-may-2022/feature-regreport
Outbreak Investigations of Cyclospora cayetanensis Infections 2013–2020: Progress Made and Challenges Remaining
Recurring outbreaks of cyclosporiasis underscore the need for a comprehensive understanding of how Cyclospora cayetanensis contaminates water and produce
By Stelios Viazis, Ph.D., Fazila K. Shakir, M.H.S., Anne Straily, D.V.M., Adrienne Goodrich-Doctor, Ph.D., Jeffery L. Sumter, Dr.P.H., and Socrates Trujillo, Ph.D.
