Monday, July 10, 2023

The New Food Safety Concern for Summer - Cyclospora

Cases of Cyclosporiasis (infection from the parasite Cyclospora) have been increasing in the US, and we have seen an increase coming from domestically grown produce, while imported produce has been historically the primary issue.  Last month, CDC reported a large outbreak of Cyclospora where imported broccoli may have been the source.

Currently, there is an ongoing outbreak in the Houston, TX area.  A source has not yet been identified, although one would expect it to be related to the consumption of fresh produce, especially those items that cannot be vigorously washed....items such as .fresh cilantro, pre-packaged salad mix, raspberries, basil, snow peas, and mesclun lettuce.

In CDC MMWR article released this week, an Florida outbreak of Cyclospora linked to bagged salad is covered with a discussion how cases have been increasing over the past year.

The symptoms They usually begin about 1 week after exposure. If the infection is not treated, symptoms can last for several weeks to a month or more. Symptoms may include the following:
  • Frequent bouts of watery diarrhea (the most 
  • common symptom)
  • Loss of appetite and weight
  • Cramping, bloating, and/or increased gas
  • Nausea (vomiting is less common)
  • Fatigue
  • Low-grade fever
https://publichealth.harriscountytx.gov/Portals/27/Documents/News/Cyclosporiasis_SM.pdf
Harris County Public Health
FOR IMMEDIATE RELEASE
July 7, 2023
Cyclospora Cases on the Rise in Harris County
HCPH urges residents to take protective measures to prevent gastrointestinal illness
HOUSTON — Harris County Public Health (HCPH), the Houston Health Department and Fort Bend
County Health & Human Services, have received reports of an increased number of Cyclospora
infections within their jurisdictions and urge people to use caution this summer while cooking and
spending time outdoors.
Cyclospora is a non-life-threatening gastrointestinal illness caused by an intestinal parasite. This parasite causes an intestinal infection called cyclosporiasis. People can become infected by consuming
contaminated food or water. 

In Texas, increased cases of Cyclosporiasis tend to occur seasonally between the months of April and
August and symptoms tend to appear between two to 14 days. Cases have been associated with the
consumption of - but not limited to - fresh produce, including fresh cilantro, raspberries, basil, snow
peas, and mesclun lettuce.

Most individuals recover with no significant health effect; however, those who are
immunocompromised, infants, or elderly, may be more affected and potentially require hospitalization
for treatment.
 
Cyclospora infects the small intestine (bowel) and usually causes watery diarrhea, with frequent,
sometimes explosive, bowel movements. Other common symptoms include loss of appetite, weight
loss, stomach cramps/pain, bloating, increased gas, nausea, and fatigue. Vomiting, body aches,
headache, fever, and other flu-like symptoms may be noted.
Some people who are infected with Cyclospora do not have any symptoms. 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. It is important to note that the disease cannot be
transmitted through direct person-to-person contact.

The health departments are investigating the cases and would like to remind people that some
gastrointestinal illnesses can spread quickly, especially during the summer.
Here are some prevention tips:
• Wash your hands with soap and water thoroughly for at least 20 seconds before and after
preparing food.
• Wash all fruits and vegetables before eating, cutting, or cooking.
2
• Wash all cutting boards, utensils, and surfaces to avoid cross-contamination.
If you or a loved one experience any of these symptoms, please reach out to your healthcare provider.


 CDC
Notes from the Field: Doubling of Cyclosporiasis Cases Partially Attributable to a Salad Kit — Florida, 2021–2022
Weekly / July 7, 2023 / 72(27);751–752
Paul Rehme, DVM1 (VIEW AUTHOR AFFILIATIONS)

Cyclosporiasis is a gastrointestinal infection caused by a protozoan parasite, Cyclospora cayetanensis. This species is only known to infect humans and is acquired when oocysts are ingested through food or water contaminated with feces that contain the parasite. The illness was first reported in 1979, and the organism was identified and named in 1994 (1). Historically, infections were typically acquired outside of the United States or from produce that was imported into the United States (1). In recent years, the number of reported U.S. cases has been increasing: cases more than doubled from 537 in 2016 to 1,194 in 2017, and then nearly tripled, to 3,519 cases in 2018; in 2019, 4,703 cyclosporiasis cases were reported.* Recently, the parasite has been found on domestically grown produce (2), and infections have been attributed to these foods (3). Produce washing will decrease but not eliminate the parasite (1).

Investigation and Outcomes

In Florida, reported numbers of cyclosporiasis cases have been increasing over the last 10 years†; 254 cases were reported in Florida in 2021, and the number doubled to 513 in 2022, including 486 (95%) laboratory-confirmed cases and 27 (5%) probable cases. Specimens from 276 (54%) cyclosporiasis patients were submitted to CDC’s Cyclospora genotyping project, including 211 (76%) which were matched to a specific temporal-genetic cluster code§ (4). Among the 513 cases reported in 2022, 469 (91%) patients reported illness onset during May 1–August 31, 2022, with a peak in early July (Figure).

The Florida Department of Health required that county public health personnel complete the CDC Cyclosporiasis National Hypothesis Generating Questionnaire (CNHGQ)¶ for all patients with illness onset dates during May 1–August 31, 2022. Among 457 completed questionnaires 330 (72%) respondents reported exposure information with no international travel, including 200 (61%) who reported exposure to bagged salad, a commercially produced package of prewashed salad greens. Among respondents reporting exposure to bagged salad, 85 (43%) noted a specific brand of Caesar salad kit containing only romaine lettuce, from a specific grocery store chain. Onset dates for this case cluster occurred during June 23–July 16, with a median disease onset date of July 1. An additional 76 persons with cyclosporiasis reported exposure to Caesar salad kits, but these persons either could not recall the salad kit brands or had purchased them from a different chain for a total of 161 potentially linked cases. Outbreaks of cyclosporiasis have been previously linked to bagged salads in the past (4). This activity was reviewed by CDC and was conducted consistent with applicable federal law and CDC policy.**

CDC uses a genotyping tool to aid epidemiologic case linkage in near-real time. Among 211 successfully genotyped specimens from Florida, 153 (73%) were assigned to the same temporal genetic cluster (2022_001), including 43 (96%) of 45 genotyped specimens linked to the bagged salad cluster and 30 (39%) of the 76 persons reporting Caesar salad kits with no further identifying information. This information was shared with the Food and Drug Administration along with source information for the implicated product from the grocery store chain to facilitate traceback of the product; however, the source of the likely contaminated product was not identified.

Preliminary Conclusions

In this investigation, results from genotyping analysis demonstrated strong agreement between the genotyping and epidemiologic data. The combination of the completed CNHGQ and genetic data strengthens evidence for identifying cases potentially linked to the same source of infection and can guide future investigations.

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