Last summer’s outbreaks turn attention to cyclosporiasis
Between a free webcast at noon today and the public release last Thursday of a blue-chip report, that uncomfortable to talk about intestinal illness known as cyclosporiasis is finally getting its due.
It’s uncomfortable for many to think about because it’s caused by the microscopic parasite Cyclospora cayetanensis. And as recently as the late 1990s, Americans did not have to worry about it unless they traveled abroad.
The world, however, changed in 1996 when Guatemalan-grown imported raspberries gave the Clyclospora parasites the ride they needed to cause a first of its kind cyclosporiasis outbreak across both the United States and Canada.
That first North American cyclosporiasis outbreak in 1996 “was an early warning to public health officials and produce industry that the international sourcing of produce means that infectious agents once thought of as only causing traveler’s diarrhea could now infect at home.”
That’s where the University of Minnesota’s Michael T. Osterholm begins a June 6 report issued by Fresh Express and its Blue-Ribbon Panel on the Prevention of Foodborne Cyclospora Outbreaks.
Osterholm chairs the Blue Ribbon Panel put together by Fresh Express after last summer’s multiple Cyclospora outbreaks in the United States. Various fresh produce items and their suppliers, including Fresh Express, were implicated. One difference between the 2018 summer’s outbreak and those occurring more than 20 years ago was some this past year “were also potentially sourced to the U.S. grown fresh produce.”
The Blue Ribbon Panel has also produced a Clyclospora Fact Sheet.
Salinas, CA-based Fresh Express put the expert panel together with members who have academic and industry backgrounds. State and federal government officials offered their expertise as observers.
The panel was assigned to work on Cyclospora cayetanensis specific issues including root-cause assessment, preventive measures and controls, collaboration, and testing validation. The June 6 report contains the group’s preliminary findings, recommendations, and continuing priorities to more effectively control and prevent Cyclospora outbreaks.
No deaths were associated with the 2018 summer Cyclospora outbreaks, but the federal Centers for Disease Control and Prevention did confirm 2,810 cyclosporiasis patients. That means there were likely thousands of additional people infected, but they were not verified.
Since 2000, CDC has logged one Cyclospora outbreak after another.
The interim report makes numerous recommendations across the various categories it has identified. Here are the panel’s continuing priorities, by category.
• Survey environmental water sources for C. cayetanensis using validated methods that should soon be available.
• Conduct a further assessment of the need for and implementation of screening for C. cayetanensis clinical infections and asymptomatic carriage of H-2A in labor pool sources (guest agricultural workers) before they enter the United States.
Additional studies are needed to determine the efficacy and safety of considering prophylactic treatment of asymptomatic infected individuals.
• Review the potential for cold-stored romaine lettuce at the implicated regional processor to be a leading indicator of epi-curve cases attributable to the H-2A farm labor pool.
• Apply tools for C. cayetanensis subtyping to resolve the possibility of multiple sources of contamination.
• Produce an explanatory fact sheet regarding C. cayetanensis infection for public education.
• Develop standardized, validated laboratory test methodologies for human specimen and environment sample testing.
• Use commonsense practices per the following food safety management systems: HACCP, GAP, GHP, SSOPs, and GMP.
• Raise C. cayetanensis awareness and GHPs to reduce potential contamination.
• Increase vigilance among growers and farm personnel of human waste in agriculture
• Provide and properly train farm crews on the care and use of restroom and handwashing
facilities, as well as appropriate usage oversite.
• Develop health and hygiene awareness programs for farm personnel.
• Exclude ill personnel from handling all raw produce and touching food contact surfaces. They should be evaluated for enteric pathogen infection and — if documented through laboratory testing to be infected with a specific pathogen — treated as is medically indicated.
• Evaluate agriculture water sources and adjacent and regional environmental water bodies for evidence of human wastewater and septic sources.
• Assess the area for evidence of noncompliance with sanitary facility use and non-farm employee human encampments.
• Increase efforts to attribute animal vector cross-contamination potential, especially birds from contaminated water bodies.
• Review the current HGQ with industry to account for changes in consumer preferences and to ensure that product descriptions are clear and readily delineated.
• Improve collection of food history data via loyalty/shopper cards and credit cards.
• Share updated case counts regularly, highlighting thresholds at which investigations are initiated and distinguishing outbreak cases from individual cases.
• Improve governmental and industry communication to convey the uncertainty around case counts.
• Establish state and CDC alignment around criteria for including an illness in the outbreak case count.
• Informally share updated case counts with company contacts so companies can make decisions to protect public health.
• Ensure that potentially interested companies have access to summaries of all cluster investigations.
• Communicate that multiple, different food products may be causing illness, and that overall case counts are not reflective of one massive outbreak.
• Aggressively work to develop genotyping or other typing methods that can be used to identify linked cases.
• Expand the matrices validated for FDA method 19B (or any updated method), improve the capacity of laboratories to analyze food samples for C. cayetanensis, and prioritize examples related to outbreaks.
• Improve the ability of states to analyze samples for C. cayetanensis.
• Develop relationships between the produce industry and the CDC’s parasitology group so that, as appropriate, the CDC can request industry information.
• Improve training and education within the food industry regarding C. cayetanensis, its host, life cycle, effective treatments, and controls, and recommended preventive measures.
• Focus on activities occurring weeks before products were harvested, keeping in mind the long C. cayetanensis life cycle.
• Conduct microscopic analysis, not just PCR, to determine the likelihood that the organism is infectious.
FDA cyclospora webcast set for today
“Cyclospora cayetanensis: The crossroads between scientific advances and knowledge gaps” is the topic of an FDA webcast lecture today by Alexandre da Silva, senior biomedical research microbiologist for FDA’s Center for Food Safety and Applied Nutrition Parasitology Laboratory.
da Silva will discuss the recent scientific advances that affected the results of the 2018 cyclosporiasis outbreak investigations and the scientific gaps that remain major public health and regulatory challenges for FDA.
The lecture begins at noon, EDT. FDA provides the details here.