Lab Matters Fall 2024 | Page 11

FROM THE BENCH

So , what are some of the key concerns and knowledge gaps that must be addressed ? First , good hygiene and sanitation practices among produce workers must be strictly enforced . Workers should avoid coming to work when ill , especially when experiencing gastrointestinal symptoms . Periodic screening of workers may be beneficial in detecting disease . Workers should also wash their hands frequently and thoroughly throughout the day . Equipment and surfaces that come into contact with produce should be cleaned regularly with appropriate types and concentrations of sanitizers to eliminate pathogens . However , the main challenge is that Cyclospora is resistant to many common sanitizers , thus adequate methods for killing oocysts must be researched . 2 , 6

Cyclospora oocysts require a period of time in the environment to sporulate before becoming infective . However , the exact timing and specific triggers of sporulation are largely unknown . The details of Cyclospora ’ s life cycle must also be investigated further . Solving the mystery of oocyst sporulation would reveal at what points in the farm-to-fork supply chain the parasite is infective and what factors trigger this sporulation ( or shift to the infective state ). Perhaps with this advancement of knowledge , methods to block sporulation could be developed and implemented as control measures at key points along the produce supply chain .

Several other essential questions persist with regard to transmission . Why are certain produce items commonly associated with outbreaks , and where does Cyclospora come from ? Is this solely a foodborne pathogen , or is contaminated water playing a role in transmission ?

Is the organism endemic in the US ? To predict and prevent the spread of this pathogen , we must know its source and what drives its movement throughout the environment . We hypothesize that Cyclospora could be found in various water sources , even treated ones , since its hardy structure allows it to resist many chemical treatments . It is possible that water could be one of the main facilitators of Cyclospora transmission .

Improvements in environmental sampling are needed to gather evidence to address these suspicions . Collection and analysis of environmental samples for Cyclospora are currently quite complicated for several reasons , including the relatively low concentrations of oocysts and the possible presence of other similar but distinct Cyclospora species — C . ashfordi and C . henanensis — as recently proposed by CDC scientists . New methods must be developed to ensure that Cyclospora is being detected even at low concentrations , with enough specificity to distinguish C . cayetanensis from other possible species , or closely related parasites . The development of swab sampling methods would also be highly beneficial , as they could be used to monitor contamination of equipment and surfaces . Lastly , the ability to genotype the collected environmental samples would enable public health professionals to connect clinical samples to environmental sources , which would be groundbreaking in improving the accuracy and efficiency of epidemiologic analyses during outbreaks .

While federal agencies in the US such as the CDC and FDA are working on initiatives such as improvement of genotyping and environmental detection methods , other aspects of this disease remain largely unknown and require further research to close gaps in knowledge . The increase in domestically acquired cases and consistent outbreak patterns in the US indicate that cyclosporiasis is a growing public health concern . An opportunity exists for public health laboratories to collaborate on research initiatives with both government and academic institutions .

Currently , one of the major barriers in research is the limited ability to obtain oocysts , as they cannot be propagated in the laboratory . Purifying oocysts from human stool samples is laborious , but increased availability would allow for significant advancements in Cyclospora research . Federal institutions may not have resources to allocate towards purification for distribution to other researchers , but this is where public health and academic laboratories could put missing puzzle pieces into place . Both offer unique potential due to the constant need for student and fellowship projects and more readily available resources . Increasing the access to Cyclospora oocysts could allow for research into major knowledge gaps in the life cycle and transmission pathways . This , coupled with federal initiatives , could allow for a shift from passive to active surveillance and aid in prevention efforts to control Cyclospora . Only with effective teamwork and collaboration across disciplines will the momentum of this pathogen be halted . Cyclospora is more than a food safety concern , but a public health concern that needs to be addressed holistically . g

References :

1 . Centers for Disease Control and Prevention [ Internet ]. 2023 . Parasites - Cyclosporiasis ( Cyclospora Infection ). Available from : https :// www . cdc . gov / parasites / cyclosporiasis / index . html #:~: text = Cyclosporiasis % 20is % 20an % 20intestinal % 20illness , water % 20contaminated % 20with % 20the % 20parasite .

2 . Response to questions posed by the Food and Drug Administration ( FDA ): Cyclospora cayetanensis in Produce [ Internet ]. National Advisory Committee on Microbiological Criteria for Foods ; 2023 . Available from : https :// www . fsis . usda . gov / sites / default / files / media _ file / documents / NACMCF _ Cyclospora _ Report _ 2023 _ Final . pdf .

3 . Li J , Cui Z , Qi M , Zhang L . Advances in Cyclosporiasis Diagnosis and Therapeutic Intervention . Front Cell Infect Microbiol . 2020 Feb 11 ; 10:43 .

4 . U . S . Food and Drug Administration [ Internet ]. 2020 . Outbreak Investigation of Cyclospora : Bagged Salads ( June 2020 ). Available from : https :// www . fda . gov / food / outbreaks-foodborne-illness / outbreak-investigation-cyclospora-bagged-salads-june-2020 .

5 . Barratt J , Ahart L , Rice M , Houghton K , Richins T , Cama V , et al . Genotyping Cyclospora cayetanensis From Multiple Outbreak Clusters With An Emphasis on a Cluster Linked to Bagged Salad Mix — United States , 2020 . The Journal of Infectious Diseases . 2022 Jun 15 ; 225 ( 12 ): 2176 – 80 .

6 . Lenaghan S . Determination of physical and chemical mechanisms to prevent Cyclospora infection [ Internet ]. Center for Produce Safety ; 2023 . Available from : https :// www . centerforproducesafety . org / amass / documents / researchproject / 461 / CPS % 20Final % 20Report % 2C % 20January % 202023 % 20- % 20Lenaghan . pdf .