The FDA reports advances in testing helped investigators during an outbreak of cyclospora infections this summer. More than 500 people were confirmed infected, but the outbreak is over according to the Centers for Disease Control and Prevention.
Outbreak investigations at state and federal levels showed a link between McDonald’s salads and sick people. Laboratory tests confirmed the microscopic cyclospora parasite in an unused package of salad mix produced for McDonald’s by a Fresh Express processor in Streamwood, IL.
Fresh Express supplies fresh produce to a variety of buyers, including foodservice operations across the country. Company officials told investigators from the Food and Drug Administration that the carrots in the implicated salad mix were used only in products for McDonald’s.
It didn’t determine the specific point in the supply chain where the contamination occurred, but the FDA was able to more quickly determine the presence of Cyclospora in this outbreak than it has been in the past.
“In 2015, FDA set up a multidisciplinary workgroup to prioritize the development, validation and implementation of a method for detecting Cyclospora in fresh produce,” according to the agency’s outbreak report. “In 2018, FDA began using the newly validated Cyclospora method. The availability of this method is a significant advancement in FDA’s ability to investigate outbreaks of cyclosporiasis and identify the parasite in foods.”
Additional outbreak details
Final outbreak statistics, as of Sept. 11, show illnesses onset dates ranged from May 20 through July 23. The infected people were from 14 to 91 years old with a median age of 52. Among ill people, two-thirds were female. No deaths were reported. There can be up to six weeks lag time between when a person becomes ill from the parasite and when their confirmed lab tests are reported to federal officials, the CDC reported.
Illinois and Iowa public health officials were the first to spot the outbreak of cyclosporiasis. The two states were hardest hit, with 271 confirmed patients in Illinois and 99 confirmed in Iowa. Missouri was third with 52 cases. Ultimately 511 people across 16 states were infected. The CDC reported 24 of the 472 patients for whom the information was available required hospitalization.
The Illinois Department of Health posted an alert on July 12 urging consumers who “ate a salad from McDonald’s since mid-May and developed diarrhea and fatigue, contact a health care provider about testing and treatment.” It takes about a week after infection for symptoms to show up, according to the CDC.
On July 13, McDonald’s stopped selling salads at more than 3,000 locations in 14 states. Soon thereafter the multi-national fast food company reported that it had replaced the supplier of salad mix in those states.
As of Sept. 13, neither Fresh Express nor the FDA had revealed the names of the produce company’s other customers that received the implicated salad product. The FDA generally does not release names of so-called trading partners because of Confidential Corporate Information issues.
The FDA finished its final analysis on July 26. It notified Fresh Express officials on July 27 of the confirmation of Cyclospora contamination. Investigators reviewed distribution and supplier information for the romaine and carrot mix, but they did not identify a single source or point of contamination for this outbreak, FDA reported.
“FDA instructed Fresh Express to determine whether potentially contaminated product (could) still be on the market. Fresh Express reported to FDA that the romaine from the same lot as the positive sample was not packaged for direct retail sale by Fresh Express and had already expired. Fresh Express committed to using recall procedures to inform those companies that received this romaine about the sample result,” according to the FDA timeline on the investigation.
In a related public alert, the USDA’s Food Safety and Inspection Service issued a public health alert July 30 on beef, pork and poultry salad and wrap products because of potential Cyclospora contamination. Caito Foods LLC of Indianapolis distributed the implicated salads and wraps. Caito Foods had received notification from Fresh Express that the chopped romaine in these products was being recalled.
Additional infections could be confirmed because the symptoms of cyclosporiasis mimic those of common viruses, according to the CDC. That makes it difficult for people to know they need to seek medical attention. The symptoms also complicate diagnosis because doctors need to order specific laboratory tests to find the infection. Specific combinations of antibiotics are necessary to kill the parasite.
“If not treated, the illness may last from a few days to a month or longer. Symptoms may seem to go away and then return one or more times — relapse. It’s common to feel very tired,” according to the CCD.
Cyclospora infects the small intestine and usually causes watery diarrhea, with frequent, sometimes explosive, bowel movements. Other common symptoms include loss of appetite, weight loss, stomach cramps and pain, bloating, increased gas, nausea and fatigue. Vomiting, body aches, headache, fever, and other flu-like symptoms may also develop. Some people who are infected with Cyclospora do not have any symptoms but can infect others.
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