McDonalds Pulls Salads After Being Linked To Cyclospora Outbreak

McDonald's restaurants in the mid-west have pulled their salads after being linked to a large outbreak of Cyclospora.  This comes after last month's outbreak linked to Del Monte's trays of sliced vegetables.

The reference below lists some of the difficulties of this parasite...one is that it may be more resistant to sanitizers and the other is the ability to attach to produce.

So basically, the parasite gets into water used for irrigation.  The source being fecal contamination from someone who became ill.  Once on the crops, it may not be easy to get rid of it.

Not a lot is know about cyclospora, one of the issues being is that humans are the only known reservoir.  This makes studying using animal models impossible.


CLINICAL MICROBIOLOGY REVIEWS,
Jan. 2010, p. 218–234 Vol. 23, No. 1
0893-8512/10/$12.00 doi:10.1128/CMR.00026-09
Copyright © 2010, American Society for Microbiology.
Update on Cyclospora cayetanensis, a Food-Borne and Waterborne Parasite
Yne´s R. Ortega* and Roxana Sanchez
University of Georgia, Center for Food Safety, Griffin, Georgia 30223-1797

"Individuals with Cyclospora infection excrete unsporulated oocysts in their feces (Fig. 1). These oocysts require 7 to 15 days to sporulate under ideal conditions (23 to 27°C) and presumably become infectious to a susceptible host. When food or water contaminated with infectious oocysts is ingested
by a susceptible host, the oocysts excyst and sporozoites are released to infect epithelial cells of the duodenum and jejunum."

"Cyclospora is highly resistant to disinfectants commonly used in food and water processing. This resistance may also be enhanced by the apparent higher binding affinities of the parasite for certain fresh produce. In the case of raspberries, which have been implicated in several outbreaks, the topography of the fruit is characterized by fine hair-like projections that facilitate the entrapment of the “sticky” Cyclospora oocysts. The microenvironment of the berry provides a favorable environment for parasite retention on the fruit. The stickiness of Cyclospora oocysts seems to be stronger than that of Cryptosporidium or Giardia oocysts. The adhesins responsible for this strong attachment to produce are unknown."

NY Times
https://www.nytimes.com/2018/07/13/us/mcdonalds-salads-illness-cyclospora-nyt.html
McDonald’s Salads Linked to Intestinal Parasite Outbreak in Midwest
By Matthew Haag
July 13, 2018



More than 100 people in the Midwest have been infected by an intestinal parasite in recent weeks that has been tied to the consumption of salads at McDonald’s, health experts announced this week.

Public health officials in Illinois and Iowa have reported a spike in cases of cyclosporiasis, with at least 15 infections in Iowa and 90 others in Illinois. Everyone who became ill in Iowa and about a quarter of those who became sick in Illinois said they had eaten McDonald’s salads in the days before symptoms appeared, according to the states’ health departments.

“Although a link has been made to salads sold in McDonald’s restaurants in some Illinois cases, public health officials continue to investigate other sources,” Dr. Nirav D. Shah, the director of the Illinois Department of Public Health, said on Thursday.

McDonald’s said Friday that “out of an abundance of caution,” it had stopped selling salads at about 3,000 restaurants in the Midwest and was working to remove the lettuce from those locations and distribution centers. The company said it was switching to another lettuce supplier at those locations.

“McDonald’s is committed to the highest standards of food safety and quality control,” the company said in a statement. “We are closely monitoring this situation and cooperating with state and federal public health authorities as they further investigate.”

Cyclosporiasis is caused by a microscopic parasite, known as cyclospora, found in food or water that has been contaminated with feces. While rarely fatal, the infection can cause severe nausea, fatigue and diarrhea for more than a week. Symptoms typically appear within a few days of infection.

Health officials in both Illinois and Iowa said that people who experienced similar symptoms after eating at McDonald’s should contact a doctor for testing and possible treatment.

The cases in Illinois first appeared in mid-May, while the illnesses in Iowa were more recent, surfacing in late June and early July.

https://www.sciencedirect.com/science/article/pii/S1286457902015551
Ecological factors influencing survival and growth of human pathogens on raw fruits and vegetables
Author links open overlay panel Larry R. Beuchat
Show more
https://doi.org/10.1016/S1286-4579(02)01555-1

Abstract

Outbreaks of human infections associated with consumption of raw fruits and vegetables have occurred with increased frequency during the past decade. Factors contributing to this increase may include changes in agronomic and processing practices, an increase in per capita consumption of raw or minimally processed fruits and vegetables, increased international trade and distribution, and an increase in the number of immuno-compromised consumers. A general lack of efficacy of sanitizers in removing or killing pathogens on raw fruits and vegetables has been attributed, in part, to their inaccessibility to locations within structures and tissues that may harbor pathogens. Understanding the ecology of pathogens and naturally occurring microorganisms is essential before interventions for elimination or control of growth can be devised.