Progress 06/01/19 to 05/31/24
Outputs
Target Audience:For the past progress report periods, the target audiences are food workers and the trade associations representing Mexican and US produce growers, in addition to importers, distributors, retailers, and governing bodies responsible for food safety regulations. All these members of the agricultural and food safety research communities in both countries stand to benefit from the knowledge generated by the project. In various reporting periods, we have reached members of the agricultural and food safety research communities in both countries through informal discussions and presentations of our work at food safety meetings in the US and internationally. Specific organizations and groups we have engaged with include: American Frozen Food Institute (AFFI), Centers for Disease Control and Prevention (CDC), Food Safety Research at GA Food Protection, Georgia Department of Agriculture, International Association for Food Protection (IAFP), International Conference for Emerging Infectious Diseases, Latin American Food Congress (CLAMISA), MIDAS Network Annual Meeting, North Carolina State University, Produce Marketing Association (PMA), Universidad Autónoma de Nuevo León, Mexico, Universidad CES, Colombia, Western Regional Center to Enhance Food Safety (WRCEFS). We have also organized a meeting of the Scientific Advisory Board where we invited academic stakeholders from Mexico and Colombia, industry contributors and extension from the US and Colombia, food safety consultants, an FDA-associated individual, and IAFP Colombia delegates including the Chair. At this meeting, we shared a summary of USDA award deliverables, outreach plans, and next steps. We plan to disseminate the results of this meeting either through a white paper or publication. To incentivize interest in the food safety area, in our last year, we convened a job panel titled "Jobs in Foods" including perspectives from Academia (Juan Leon), Government (the Association of Food and Drug Officials - AFDO, Jessica Badour), and Industry (past CEO of KH International, Karen Holzberg). It was attended by 54 students including PhD, MPH, and undergraduates. We have also mentored a total of36 trainee-years in agricultural, food, norovirus, and COVID-19 research ranging from masters students, doctoral students, professional staff, and faculty in the US and Mexico. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?During the project, a total of 36 trainee-years received professional training in various areas including project management, experimental design, laboratory techniques, modeling techniques, statistical analysis, outreach and communication, and scientific writing. The trainee-years included 15 masters students, 8 doctoral students, 1 postdoctoral fellow, 3 professional staff, 1 administrative staff, and 8 scientists (5 faculty). Additionally, a job panel titled "Jobs in Foods" was convened, featuring perspectives from academia, government, and industry, and attended by 54 students including PhD, MPH, and undergraduates. This comprehensive training and professional development effort aimed to enhance skills and knowledge in food safety and fields that support food safety. How have the results been disseminated to communities of interest?The results of the project have been disseminated through various channels (see Products and Other Products Y1-5, Final) including peer-reviewed publications, presentations at US and international professional conferences, webinars, interviews, and infographics. Specific organizations and groups we have engaged with include: American Frozen Food Institute (AFFI), Centers for Disease Control and Prevention (CDC), Food Safety Research at GA Food Protection, Georgia Department of Agriculture, International Association for Food Protection (IAFP), International Conference for Emerging Infectious Diseases, Latin American Food Congress (CLAMISA), MIDAS Network Annual Meeting, North Carolina State University, Produce Marketing Association (PMA), Universidad Autónoma de Nuevo León, Mexico, Universidad CES, Colombia, Western Regional Center to Enhance Food Safety (WRCEFS). A meeting of the Scientific Advisory Board was organized, inviting academic stakeholders from Mexico and Colombia, industry contributors and extension from the US and Colombia, food safety consultants, an FDA-associated individual, and IAFP Colombia delegates. At this meeting, we shared a summary of USDA award deliverables, outreach plans, and next steps. We plan to further disseminate this summary through a white paper or publication. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
During the project period, we successfully achieved all stated objectives. Please find a summary of each below: OBJECTIVE 1: Develop a validated laboratory method to quantify the frequency of infectious norovirus contamination in the agricultural environment. This study used a novel paired sampling strategy to evaluate transmission routes of norovirus contamination on fresh produce farms in Nuevo Leon, Mexico. Samples included 82 composite produce rinses, 49 composite hand rinses, 27 irrigation waters, and 27 source waters from cantaloupe, jalapeno, and tomato farms. Norovirus RNA was detected using reverse transcriptase real-time PCR. Norovirus contamination of produce was more prevalent post-harvest compared to pre-harvest (OD [95% CI] = 3.6 [1.1, 11.8]; p = 0.04). A high proportion of source water (44.4%), irrigation water (40.7%) and farmworker hand rinse samples (26.5%) were positive for human norovirus. There were no statistically significant positive correlations between norovirus and bacterial (Escherichia. coli, coliforms, Enterococcus, Bacteroidales) or viral (somatic coliphages) indicators. There was no association between presence of norovirus on produce and matched hand or agricultural water samples, however, levels of GI norovirus on produce, hands, and irrigation water samples were statistically significant using a linear mixed modeling approach. For microbial indicators, there was a clear association between produce and matched hand, but not agricultural water contamination. Though norovirus RNA was identified in the production environment, the transmission pathways for norovirus on produce farms differ from those of indicator organisms, We published a systematic review examining whether indicator organisms could be surrogates for norovirus and hepatitis A in the agricultural environment With regards to new methods, we have attempted and documented two unsuccessful methods to quantify norovirus contamination. The first method was the adaptation of the one-step CDC protocol for recombinant genotyping to agricultural samples (produce, water, hands). We found the CDC protocol, despite enhancements in assay conditions, was not able to sensitively classify norovirus strains in agricultural samples. The results of this work was written up in a Masters thesis. (Kathleen Goodwin, Environmental Health Title of MPH Thesis: Development of Dual Genotyping Protocol for Agricultural Norovirus, 2023). The second method was a collaboration with FDA to use next generation sequencing to detect and classify norovirus strains from our positive agricultural samples. Unfortunately, the FDA assay conditions required a re-extraction of our samples with salmon carrier DNA. Despite re-extracting 40 originally positive norovirus samples, not one was positive suggesting that the elimination of the salmon carrier DNA could have reduced the viral recover sensitivity. We have sought to validate three proxy assays for norovirus infectivity: capsid integrity (RNase pretreatment followed by qRT-PCR amplification), viral binding (porcine gastric mucin assays [PGM]), entry, replication egress (enteroid infectivity). We are validating these assays with Norwalk inoculum used to dose human volunteers. At the time of this writing, we have: 1) re-quantified and re-calibrated our norovirus inoculum; 2) completed the validation of the RNAse pre- treatment assay; 3) and received confirmation of success of the validation of the PGM assay with Dr. Kali Kniel at University of Delaware. With regards to developing a new method, with the Universidad Autonoma de Nuevo Leon - Mexico, we have developed a new CRISPR- based murine norovirus (MNV-1) detection assay for blueberries and lettuce. This assay is combined with an RNAse pretreatment step, based on the past work. We have validated this method, ensured it does not cross-react with other viruses, and measured its limit of detection. This work was accepted to be presented at IAFP (July 2024) and is soon to be submitted for publication. The citation for the presentation is below: Ossio A, Merino-Mascorro JA, Garcia S, LEON JS, Heredia N. Novel CRISPR-RNase Based Method For Detection Of Potentially Infectious Viruses In Produce. International Association for Food Protection Annual Meeting. July 14 - July 17, 2024. Long Beach Convention Center, Long Beach, California OBJECTIVE 2: Develop an integrated Quantitative Microbial Risk Assessment (QMRA) and Infectious Disease Transmission Model (IDT) that simulates the impact of norovirus contamination of produce and strategies for their control AND that simulates the impact of SARS-CoV-2 infection of essential produce food workers and prioritizes strategies for its control. We developed and published (see Products Y1-5, Final) on a norovirus Quantitative Microbial Risk assessment model in the production environment for lettuce, tomatoes, and raspberries. Our results recommended that combined hand hygiene and worker furlough practices, with an emphasis on handwashing, substantially reduce consumer risk from norovirus-contaminated produce. This is the first evaluation of and advances the evidence for the impact of global produce safety regulations on norovirus contamination control and risk mitigation measures. Upon request of several produce trade associations, due to the pandemic, and with permission of USDA, we expanded this objective to also include SARS-CoV-2 (originally the focus was only norovirus). We applied our modeling approaches (QMRA & QMRA-IDT) to recommend food worker practice conditions in several environments (production, processing, cold-chain) that reduce the risk of worker infections and outbreaks and provided evidence for the low risk of cold-chain contamination with SARS-CoV-2. This work was presented at several scientific meetings, with government, academia, and produce associations and published (see Products Y1-5, Final) We also developed an QMRA-IDT model for norovirus and presented this during the dissertation presentation and published work of Julia Sobolik and also were accepted to present this work at two meetings. Sobolik JS, Sajewski E, Lopman B, LEON JS. Norovirus individual and population-level infection risks associated with consumption of contaminated tomatoes - an application of a novel QMRA-IDT model. American Society for Tropical Medicine and Hygiene (ASTMH). November 13-17, 2024. New Orleans, Louisiana LEON JS, Sajewski E, Lopman B, Sobolik JS. The infection risks from consumption of norovirus-contaminated tomatoes to individuals and populations - application of a novel risk assessment model to support the Codex Alimentarius. International Association for Food Protection Annual Meeting (IAFP)-Latino. November 11-14, 2024. Sao Paulo, Brazil OBJECTIVE 3: Identify produce safety strategies to reduce infectious norovirus contamination on produce in the harvest and post-harvest environment that maximize public health impact. In our published QMRA model (see Products Y1-5, Final), individual interventions modeled (hand hygiene and worker furlough) did not reduce produce contamination to below the norovirus infectious dose. Handwashing compliance of 100% (specifying a 2.0 log10 virus removal) did not eliminate contamination and provided an estimated range of 3.59-6.14 log10 residual viruses per commodity following the first tactile event. Combined interventions (glove use and handwashing, glove use and worker furlough, or handwashing and worker furlough) reduced viral contamination across all commodities with the largest contamination reduction resulting from 100% handwashing compliance at a maximum 6 log10 virus removal (0.39-138 residual virus). Translating produce contamination to maximum consumer infection risk, 100% handwashing with a 5 log10 virus removal was necessary to achieve an infection risk below the threshold of 0.032 infections per consumption event.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Sobolik JS, Newman KL, Jaykus LA, LEON JS. Characterizing norovirus transmission and infection risks in the fresh produce agricultural environment. SS-AOAC International Annual Meeting. April 19-21, 2022.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Sobolik JS, Jaykus LA, LEON JS. SARS-CoV-2 Fomite risks and mitigation strategies associated with cold-chain food packaging. International Food and Environmental Virology Annual Meeting. May 16-20, 2022.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Sobolik JS, Prince-Guerra J, Jaykus LA, Heredia N., Garcia S., LEON JS. Norovirus detection in fresh produce, water, and hand rinses: an evaluation of environmental transmission in an agriculture setting. International Association for Food Protection Annual Meeting. July 31-August 3, 2022.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Sajewski E, Sobolik JS, Kraay A, Jaykus LA, Lopman B, LEON JS. Evaluating the impacts of vaccination, testing, and masking on SARS-CoV-2 transmission among food workers: a novel integrated modeling approach. MIDAS Network Annual Meeting, Virtual. September 7-9, 2022.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Sobolik JS, Newman KL, Jaykus LA, LEON JS. Hand Hygiene Interventions to Reduce Norovirus Contamination of Ready-to-Eat Fresh Produce during Produce Harvesting and Packing on Farms. Poster Presentation at Food Safety Research at GA Food Protection, September 16 2019.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Ge Y, LEON J, Koelle K, Lopman B, Atmar R, Handel H. The association between norovirus infection outcomes and inoculum dose. 2021 MIDAS Network Annual Meeting
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Sajewski E, Sobolik JS, Kraay ANM, LEON JS, Lopman B. (2021). Protecting essential workers from COVID-19 in an indoor food processing facility: a novel integrated QMRA-IDT modeling approach. Poster presentation at: Epidemics 8, November 30-December 3, 2021.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Cooper DK, Sobolik JS, Kovacevic J, Rock C, Sajewski E, Guest J, Lopman B, Jaykus LA, LEON JS. (2022). Protection of the Essential Workforce from Occupationally-Acquired Sars-Cov-2: A Quantitative Risk Model on the Efficacy of Infection Control Interventions in Produce Production and Processing. Poster presentation at: International Association for Food Protection Meeting, Pittsburgh, PA. July 31 August 3, 2022.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Sajewski E, Sobolik JS, Kraay A, Jaykus LA, Lopman B, LEON JS. (2022). Evaluating, among food workers, the impacts of vaccination, testing, and non-pharmaceutical interventions on SARS-CoV-2 transmission: a novel integrated QMRA-IDT modeling approach. Poster presentation at: International Association for Food Protection Meeting, Pittsburgh, PA. July 31 August 3, 2022.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Rodriguez Morales CK, LEON JS. Health Communications for Migrant Produce Workers in the United States. International Conference for Emerging Infectious Diseases 2022. Aug 10. Atlanta Georgia
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2023
Citation:
Ge Y, Billings WZ, Opekun A, Estes M, Graham D, LEON J, Koelle K, Shen Y, Atmar R, Lopman B, Handel A. Effect of Norovirus Inoculum Dose on Virus Kinetics, Shedding, and Symptoms. Emerg Infect Dis. 2023 Jul;29(7):1349-1356. doi: 10.3201/eid2907.230117. PMID: 37347494; PMCID: PMC10310361.
- Type:
Peer Reviewed Journal Articles
Status:
Published
Year Published:
2024
Citation:
Victor CP, LEON JS, Williams AM. Vitamin A biomarkers were associated with ?(1)-acid glycoprotein and C-reactive protein over the course of a human norovirus challenge infection. Br J Nutr. 2024 Feb 14;131(3):482-488. doi: 10.1017/S0007114523002076. Epub 2023 Sep 11. PMID: 37694547; PMCID: PMC10784129.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Sobolik JS, Cooper DK, Jaykus LA, Sajewski E, LEON JS. SARS-CoV-2 transmission risks and risk mitigation strategies among essential workers in an indoor food processing facility. GAFP Fall Meeting 2021, Virtual. October 19, 2021.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Cooper DK, Sobolik JS, Sajewski E, Leon JS. Characterizing the risk of SARS-CoV-2 infection among essential food workers: a quantitative microbial risk assessment approach. GAFP Fall Meeting 2021, Virtual. October 19, 2021.
|
Progress 06/01/23 to 05/31/24
Outputs
Target Audience:For the past progress report period, target audiences are food workers and the trade associations representing Mexican and US produce growers, in addition to importers, distributors, retailers, and governing bodies responsible for food safety regulations. All these members of the agricultural and food safety research communities in both countries all stand to benefit from the knowledge generated by the project. In this reporting period, we have reached members of the agricultural and food safety research communities in both countries through informal discussions and presentation of our work at food safety meetings in the US and internationally. We have also organized a meeting of the Scientific Advisory Board where we also invited academic stakeholders from Mexico and Colombia, industry contributors and extension from the US and Colombia, food safety consultants, an FDA-associated individual, and IAFP Colombia delegates including the Chair. At this meeting, we shared a summary of USDA award deliverables, outreach plans, and next steps. We plan to also disseminate the results of this meeting either through a white paper or publication. To incentivize interest in the food safety area, we convened a job panel titled "Jobs in Foods" including perspectives from Academia (Juan Leon), Government (the Association of Food and Drug Officials - AFDO, Jessica Badour), and Industry (past CEO of KH International, Karen Holzberg). It was attended by 54 students including PhD, MPH, and undergraduates. We have also mentored 4 individuals in agricultural, food, norovirus, and COVID-19 ranging from masters students (1), doctoral students (2), and faculty (1), in the US and Mexico. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?During the current reporting period, a total of 4 individuals have received professional training in project management, experimental design, modeling techniques, statistical analysis, outreach and communication, and scientific writing. Trainees included 1 masters students, 2 doctoral students, 1 faculty during the reporting period. To incentivize interest in the food safety area, we convened a job panel titled "Jobs in Foods" including perspectives from Academia (Juan Leon), Government (the Association of Food and Drug Officials - AFDO, Jessica Badour), and Industry (past CEO of KH International, Karen Holzberg). It was attended by 54 students including PhD, MPH, and undergraduates. How have the results been disseminated to communities of interest?The products described above, including submitted peer reviewed publications and presentations at US and international professional conferences have all served to disseminate research results and engage communities of interest. We have also organized a meeting of the Scientific Advisory Board where we also invited academic stakeholders from Mexico and Colombia, industry contributors and extension from the US and Colombia, food safety consultants, an FDA-associated individual, and IAFP Colombia delegates including the Chair. At this meeting, we shared a summary of USDA award deliverables, outreach plans, and next steps. We have specifically reached out to members of the produce community, including the American Frozen Food Institute (AFFI), trade associations and companies, US government agencies (Centers for Disease Control and Prevention [CDC]), Mexican food safety researchers and extension at the Universidad Autonoma de Nuevo Leoon, Mexico and Colombian food safety researchers and extension at Universidad CES. What do you plan to do during the next reporting period to accomplish the goals?The project ended on May 31, 2024 and there is no further reporting period.
Impacts
What was accomplished under these goals?
OBJECTIVE 1: Develop a validated laboratory method to quantify the frequency of infectious norovirus contamination in the agricultural environment. In this reporting period, we have sought to validate three proxy assays for norovirus infectivity: capsid integrity (RNase pretreatment followed by qRT-PCR amplification), viral binding (porcine gastric mucin assays [PGM]), entry, replication egress (enteroid infectivity). We are validating these assays with Norwalk inoculum used to dose human volunteers. At the time of this writing, we have: 1) re-quantified and re-calibrated our norovirus inoculum; 2) completed the validation of the RNAse pre-treatment assay; 3) and received confirmation of success of the validation of the PGM assay with Dr. Kali Kniel at University of Delaware. With regards to new methods, with the Universidad Autonoma de Nuevo Leon - Mexico, we have developed a new CRISPR-based murine norovirus (MNV-1) detection assay for blueberries and lettuce. This assay is combined with an RNAse pretreatment step, based on the past work. We have validated this method, ensured it does not cross-react with other viruses, and measured its limit of detection. This work was presented at IAFP (July 2024) and is soon to be submitted for publication. The citation for the presentation is below: Ossio A, Merino-Mascorro JA, Garcia S, LEON JS, Heredia N. Novel CRISPR-RNase Based Method For Detection Of Potentially Infectious Viruses In Produce. International Association for Food Protection Annual Meeting. July 14 - July 17, 2024. Long Beach Convention Center, Long Beach, California OBJECTIVE 2: Develop an integrated Quantitative Microbial Risk Assessment (QMRA) and Infectious Disease Transmission Model (IDT) that simulates the impact of norovirus contamination of produce and strategies for their control AND that simulates the impact of SARS-CoV-2 infection of essential produce food workers and prioritizes strategies for its control. As described in the past progress report, this Objective was completed for Norovirus and published it in Sobolik JS, Newman KL, Jaykus LA, Bihn EA, LEON JS. Norovirus transmission mitigation strategies during simulated produce harvest and packing. Int J Food Microbiol. 2021 Nov 2;357:109365. doi: 10.1016/j.ijfoodmicro.2021.109365. Epub 2021 Aug 20. PMID: 34488004; PMCID: PMC8510003. As an add-on, we continue to work on developing the IDT model side based on our published QMRA model and empirical data from our laboratory studies of viral contamination of produce in the production, harvest and processing environment. We have presented this work in two meetings (November 2024): Sobolik JS, Sajewski E, Lopman B, LEON JS. Norovirus individual and population-level infection risks associated with consumption of contaminated tomatoes - an application of a novel QMRA-IDT model. American Society for Tropical Medicine and Hygiene (ASTMH). November 13-17, 2024. New Orleans, Louisiana LEON JS, Sajewski E, Lopman B, Sobolik JS. The infection risks from consumption of norovirus-contaminated tomatoes to individuals and populations - application of a novel risk assessment model to support the Codex Alimentarius. International Association for Food Protection Annual Meeting (IAFP)-Latino. November 11-14, 2024. Sao Paulo, Brazil As described in the past progress report, this Objective was completed for SARS-CoV-2 and published it in Sobolik JS, Sajewski ET, Jaykus LA, Cooper DK, Lopman BA, Kraay ANM, Ryan PB, LEON JS. Controlling risk of SARS-CoV-2 infection in essential workers of enclosed food manufacturing facilities. Food Control. 2022 Mar;133:108632. doi: 10.1016/j.foodcont.2021.108632. Epub 2021 Oct 22. PMID: 34703082; PMCID: PMC8532033. Sobolik JS, Sajewski ET, Jaykus LA, Cooper DK, Lopman BA, Kraay ANM, Ryan PB, Guest JL, Webb-Girard A, LEON JS. Decontamination of SARS-CoV-2 from cold-chain food packaging provides no marginal benefit in risk reduction to food workers. Food Control. 2022 Jun;136:108845. doi: 10.1016/j.foodcont.2022.108845. Epub 2022 Jan 20. PMID: 35075333; PMCID: PMC8770992. OBJECTIVE 3: Identify produce safety strategies to reduce infectious norovirus contamination on produce in the harvest and post-harvest environment that maximize public health impact. This objective was completed as described in the prior progress report and also in Sobolik JS, Newman KL, Jaykus LA, Bihn EA, LEON JS. Norovirus transmission mitigation strategies during simulated produce harvest and packing. Int J Food Microbiol. 2021 Nov 2;357:109365. doi: 10.1016/j.ijfoodmicro.2021.109365. Epub 2021 Aug 20. PMID: 34488004; PMCID: PMC8510003.
Publications
|
Progress 06/01/22 to 05/31/23
Outputs
Target Audience:For the past progress report period, target audiences are food workers and the trade associations representing Mexican and US produce growers, in addition to importers, distributors, retailers, and governing bodies responsible for food safety regulations. All these members of the agricultural and food safety research communities in both countries all stand to benefit from the knowledge generated by the project. In this reporting period, we have reached members of the agricultural and food safety research communities in both countries through informal discussions and presentation of our work at food safety meetings in the US (International Association for Food Protection, International Conference for Emerging Infectious Diseases, Latin American Food Congress). We have also mentored 7 individuals in agricultural, food, norovirus, and COVID-19 ranging from masters students (5), doctoral students (1), and faculty (1), in the US. Changes/Problems:Because of the impact of the pandemic, Emory University laboratories were shut down during Year 1 and 2 of this project and only pandemic-related laboratory research was permitted. USDA-NIFA generously provided two separate 1 year no- cost extension and we have maximized their use by continuing our laboratory work. What opportunities for training and professional development has the project provided?During the current reporting period, a total of 6 individuals have received professional training in project management, experimental design, modeling techniques, statistical analysis, outreach and communication, and scientific writing. Trainees included 5 masters students and 1 doctoral student during the reporting period. How have the results been disseminated to communities of interest?The products described above, including submitted peer reviewed publications and presentations at international professional conferences have all served to disseminate research results and engage communities of interest. For example, we presented our partnership, with the Western Regional Center to Enhance Food Safety (WRCEFS) to develop infographics, based on federal guidance, that could support the food industry in protecting their employees from COVID-19, at the following conference: Rodriguez Morales CK, LEON JS. Health Communications for Migrant Produce Workers in the United States. International Conference for Emerging Infectious Diseases 2022. Aug 10. Atlanta Georgia What do you plan to do during the next reporting period to accomplish the goals?Objective 1: We aim to begin the validation of the two remaining assays (PGM assay and enteroid infectivity assay) with infectious norovirus inoculum. Objective 2: Objective 2 is completed but we also wish to develop a norovirus QMRA-IDT model as well as a SARS-CoV-2 model. Objective 3: Objective 3 is completed, but we wish to expand it and will also develop an IDT model that will allow us to quantify the US burden based on empirical laboratory data.
Impacts
What was accomplished under these goals?
OBJECTIVE 1: Develop a validated laboratory method to quantify the frequency of infectious norovirus contamination in the agricultural environment. In this reporting period, we have sought to validate three proxy assays for norovirus infectivity: capsid integrity (RNase pretreatment followed by qRT-PCR amplification), viral binding (porcine gastric mucin assays [PGM]), entry, replication egress (enteroid infectivity). We are validating these assays with Norwalk inoculum used to dose human volunteers. At the time of this writing, we have: 1) re-quantified and re-calibrated our norovirus inoculum; 2) completed the validation of the RNAse pre-treatment assay; 3) began experimental approach discussions with Dr. Kali Kniel at University of Delaware for the outsourcing of the PGM assay; 4) secured the commitment of Dr. Malik Esseli who is willing to test their enteroid model and are waiting the delivery of hard-to-obtain enteroid reagents.. With regards to new methods, we have attempted and documented two unsuccessful methods to quantify norovirus contamination. The first method was the adaptation of the one-step CDC protocol for recombinant genotyping to agricultural samples (produce, water, hands). We found the CDC protocol, despite enhancements in assay conditions, was not able to sensitively classify norovirus strains in agricultural samples. The results of this work was written up in a Masters thesis. (Kathleen Goodwin, Environmental Health Title of MPH Thesis: Development of Dual Genotyping Protocol for Agricultural Norovirus, 2023). The second method was a collaboration with FDA to use next generation sequencing to detect and classify norovirus strains from our positive agricultural samples. Unfortunately, the FDA assay conditions required a re-extraction of our samples with salmon carrier DNA. Despite re-extracting 40 originally positive norovirus samples, not one was positive suggesting that the elimination of the salmon carrier DNA could have reduced the viral recover sensitivity. OBJECTIVE 2: Develop an integrated Quantitative Microbial Risk Assessment (QMRA) and Infectious Disease Transmission Model (IDT) that simulates the impact of norovirus contamination of produce and strategies for their control AND that simulates the impact of SARS-CoV-2 infection of essential produce food workers and prioritizes strategies for its control. As described in the past progress report, this Objective is completed for Norovirus and published it in • Sobolik JS, Newman KL, Jaykus LA, Bihn EA, LEON JS. Norovirus transmission mitigation strategies during simulated produce harvest and packing. Int J Food Microbiol. 2021 Nov 2;357:109365. doi: 10.1016/j.ijfoodmicro.2021.109365. Epub 2021 Aug 20. PMID: 34488004; PMCID: PMC8510003. • As an add-on, we continue to work on developing the IDT model side based on our published QMRA model and empirical data from our laboratory studies of viral contamination of produce in the production, harvest and processing environment As described in the past progress report, this Objective is completed for SARS-CoV-2 and published it in • Sobolik JS, Sajewski ET, Jaykus LA, Cooper DK, Lopman BA, Kraay ANM, Ryan PB, LEON JS. Controlling risk of SARS-CoV-2 infection in essential workers of enclosed food manufacturing facilities. Food Control. 2022 Mar;133:108632. doi: 10.1016/j.foodcont.2021.108632. Epub 2021 Oct 22. PMID: 34703082; PMCID: PMC8532033. • Sobolik JS, Sajewski ET, Jaykus LA, Cooper DK, Lopman BA, Kraay ANM, Ryan PB, Guest JL, Webb-Girard A, LEON JS. Decontamination of SARS-CoV-2 from cold-chain food packaging provides no marginal benefit in risk reduction to food workers. Food Control. 2022 Jun;136:108845. doi: 10.1016/j.foodcont.2022.108845. Epub 2022 Jan 20. PMID: 35075333; PMCID: PMC8770992. We have a new publication quantifying the cumulative risk of SARS-CoV2 exposure of an indoor and outdoor produce worker. Cooper DK, Sobolik JS, Kovacevic J, Rock C, Sajewski E, Guest J, Lopman B, Jaykus LA, LEON JS. (2022). Protection of the Essential Workforce from Occupationally-Acquired Sars-Cov-2: A Quantitative Risk Model on the Efficacy of Infection Control Interventions in Produce Production and Processing. Poster presentation at: International Association for Food Protection Meeting, Pittsburgh, PA. July 31 - August 3, 2022. OBJECTIVE 3: Identify produce safety strategies to reduce infectious norovirus contamination on produce in the harvest and post-harvest environment that maximize public health impact. This objective was completed as described in the prior progress report and also in • Sobolik JS, Newman KL, Jaykus LA, Bihn EA, LEON JS. Norovirus transmission mitigation strategies during simulated produce harvest and packing. Int J Food Microbiol. 2021 Nov 2;357:109365. doi: 10.1016/j.ijfoodmicro.2021.109365. Epub 2021 Aug 20. PMID: 34488004; PMCID: PMC8510003. As described in Objective 2, we are also developing an IDT model that will allow us to quantify the US burden based on empirical laboratory data.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2023
Citation:
Cooper DK, Sobolik JS, Kovacevic J, Rock CM, Sajewski ET, Guest JL, Lopman BA, Jaykus LA, LEON JS. Combined Infection Control Interventions Protect Essential Food Workers from Occupational Exposures to SARS-CoV-2 in the Agricultural Environment. Appl Environ Microbiol. 2023 Jun 13:e0012823. doi: 10.1128/aem.00128-23. Epub ahead of print. PMID: 37310232.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
LEON JS (2022). Riesgos de pat�genos virales en la cadena agroalimentaria. CLAMISA: Congreso Latinoamericano de Alimentos: Una Mirada Integral a los Sistemas Alimentarios. November 17, Medell�n, Colombia. Invited Speaker.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
iv. Cooper DK, Sobolik JS, Kovacevic J, Rock C, Sajewski E, Guest J, Lopman B, Jaykus LA, LEON JS. (2022). Protection of the Essential Workforce from Occupationally-Acquired Sars-Cov-2: A Quantitative Risk Model on the Efficacy of Infection Control Interventions in Produce Production and Processing. Poster presentation at: International Association for Food Protection Meeting, Pittsburgh, PA. July 31 August 3, 2022.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2023
Citation:
Evaluating norovirus contamination of fresh produce on US and Mexican farms and mitigating SARS-CoV-2 risk among essential food workers Restricted; Files Only
Sobolik, Julia (Spring 2023)
Permanent URL: https://etd.library.emory.edu/concern/etds/s4655h990?locale=en
Published
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Sajewski E, Sobolik JS, Kraay A, Jaykus LA, Lopman B, LEON JS. (2022). Evaluating, among food workers, the impacts of vaccination, testing, and non-pharmaceutical interventions on SARS-CoV-2 transmission: a novel integrated QMRA-IDT modeling approach. Poster presentation at: International Association for Food Protection Meeting, Pittsburgh, PA. July 31 August 3, 2022.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2022
Citation:
Rodriguez Morales CK, LEON JS. Health Communications for Migrant Produce Workers in the United States. International Conference for Emerging Infectious Diseases 2022. Aug 10. Atlanta Georgia
|
Progress 06/01/21 to 05/31/22
Outputs
Target Audience:For the past progress report period, target audiences are the trade associations representing Mexican and US produce growers, in addition to importers, distributors, retailers, and governing bodies responsible for food safety regulations. All these members of the agricultural and food safety research communities in both countries all stand to benefit from the knowledge generated by the project. As described in the last progress report, to formalize the goals of the last progress report, we aimed to expand Objective 2, to protecting food workers from COVID-19 illness, given the disproportionate effect of the pandemic on this population. Thus, the target audience for this expanded objective are food workers in both the US and Mexico and their representative trade associations, and regulatory and protective government bodies in both countries as they all stand to benefit from the results and recommendations derived from this expanded objective In this reporting period, we have reached members of the agricultural and food safety research communities in both countries through informal discussions and presentation of our work at food safety meetings in the US (International Association for Food Protection, Western Regional Center to Enhance Food Safety, MIDAS Network Annual Meeting). We have also engaged in multiple webinars and presentations to share both norovirus and COVID-19 related information to the food and agricultural communities. We have also mentored 7 individuals in food safety ranging from a professional staff member (1), masters students (3), doctoral students (2), and faculty (1), in the US. Efforts: We have specifically reached out to members of the produce community, including the Produce Marketing Association (PMA), American Frozen Food Institute (AFFI), Centers for Disease Control and Prevention (CDC), Western Regional Center to Enhance Food Safety (WRCEFS), and North Carolina State University and Mexican researchers at the Universidad Autónoma de Nuevo León, Mexico. We have three publications published, two submitted, and two under preparation. We also have multiple conference abstracts accepted and webinars. We also provide annual trainings to thesis and research students. With regards to COVID-19 outreach, we worked closely with AFFI and WRCEFS to develop guidance to support their efforts and those of the food industry constituents they represent. Changes/Problems:Because of the impact of the pandemic, Emory University laboratories were shut down during the previous period of this progress report and only pandemic-related laboratory research was permitted. USDA-NIFA generously provided a 1 year no-cost extension and we have maximized its use by restarting our laboratory work. What opportunities for training and professional development has the project provided?During the current reporting period, a total of 7 individuals have received professional training in project management, experimental design, modeling techniques, statistical analysis, outreach and communication, and scientific writing in food safety. Trainees included 3 masters students, 2 doctoral students, 1 professional staff, and 1 scientist (1 faculty) during the reporting period. How have the results been disseminated to communities of interest?The products described above, including submitted peer reviewed publications and presentations at international professional conferences have all served to disseminate research results and engage communities of interest. As described in preceding sections, we have also developed webinars, presentations and infographics. For example, we partnered with the Western Regional Center to Enhance Food Safety (WRCEFS) to develop infographics, based on federal guidance, that could support the food industry in protecting their employees from COVID-19. These infographics can be found in: https://agsci.oregonstate.edu/wrcefs/covid-19-resources. They have been shared by various constituents including the Georgia Department of Agriculture, for example, in their Food Safety Division's weekly update. The results of this work have also been used directly to influence policy or practices. For example, the SARS-CoV-2 work was used by colleagues in response to proposed state policies for managing COVID-19 transmission in key agricultural food production and manufacturing workforces. These results were also used by AFFI to advocate for removing the ineffective food packaging disinfection of food packaging imported into China. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: We aim to validate the two remaining assays (PGM assay and enteroid infectivity assay) with infectious norovirus inoculum. Objective 2: Based on the experience derived from the SARS-CoV-2 QMRA-IDT model, we will apply it to developing a norovirus QMRA-IDT model. We are awaiting the outcome of the submission of the two SARS-CoV-2 publications and may resubmit as needed. Objective 3: Objective 3 is completed, but we wish to expand it and will also develop an IDT model that will allow us to quantify the US burden based on empirical laboratory data.
Impacts
What was accomplished under these goals?
IMPACT OF PROJECT: The first main deliverable are laboratory assays that can detect infectious norovirus on fresh produce (Objective 1). The second main deliverable will lead to proven risk-management strategies that control infectious norovirus contamination on produce in farms and packing facilities and can be extended to other foodborne pathogens (Objective 2-3). These two deliverables will 1) allow individuals to detect norovirus on fresh produce that can make consumers sick; 2) propose effective strategies to reduce the risk of this from happening. Based on the approval from the past reporting period, a third deliverable (Objective 2) is guidance, based on quantitative risk assessment, for food managers, trade association, and governments in how best to protect their produce workers from SARS-CoV-2. Overall, these impacts will improve the safety of U.S. agricultural markets and consumers and improve the U.S. agricultural economy. OBJECTIVE 1: Develop a validated laboratory method to quantify the frequency of infectious norovirus contamination in the agricultural environment. Due to the pandemic, Emory University laboratories were closed for non-essential research during the period progress report period, and laboratory work on Objective 1 stopped. Since the reopening of the Emory laboratories we have sought to validate three proxy assays for norovirus infectivity: capsid integrity (RNase pretreatment followed by qRT-PCR amplification), viral binding (porcine gastric mucin assays [PGM]), entry, replication egress (enteroid infectivity). We are validating these assays with Norwalk inoculum used to dose human volunteers. At the time of this writing, we have: 1) completed the validation of the RNAse pre-treatment assay; 2) identified collaborators for the outsourcing of the PGM assay; 3) secured the commitment of a collaborator who is willing to test their enteroid model and shared Norwalk inoculum with them for testing (they are currently testing the infectivity of the Norwalk strain with mixed results). OBJECTIVE 2: Develop an integrated Quantitative Microbial Risk Assessment (QMRA) and Infectious Disease Transmission Model (IDT) that simulates the impact of norovirus contamination of produce and strategies for their control AND that simulates the impact of SARS-CoV-2 infection of essential produce food workers and prioritizes strategies for its control. For our Norovirus work, We have completed the QMRA work and published it in Sobolik JS, Newman KL, Jaykus LA, Bihn EA, LEON JS. Norovirus transmission mitigation strategies during simulated produce harvest and packing. Int J Food Microbiol. 2021 Nov 2;357:109365. doi: 10.1016/j.ijfoodmicro.2021.109365. Epub 2021 Aug 20. PMID: 34488004; PMCID: PMC8510003. We are working on developing the IDT model side based on our published QMRA model and empirical data from our laboratory studies of viral contamination of produce in the production, harvest and processing environment For our SARS-CoV-2 work, we have published our work in two publications Sobolik JS, Sajewski ET, Jaykus LA, Cooper DK, Lopman BA, Kraay ANM, Ryan PB, LEON JS. Controlling risk of SARS-CoV-2 infection in essential workers of enclosed food manufacturing facilities. Food Control. 2022 Mar;133:108632. doi: 10.1016/j.foodcont.2021.108632. Epub 2021 Oct 22. PMID: 34703082; PMCID: PMC8532033. Sobolik JS, Sajewski ET, Jaykus LA, Cooper DK, Lopman BA, Kraay ANM, Ryan PB, Guest JL, Webb-Girard A, LEON JS. Decontamination of SARS-CoV-2 from cold-chain food packaging provides no marginal benefit in risk reduction to food workers. Food Control. 2022 Jun;136:108845. doi: 10.1016/j.foodcont.2022.108845. Epub 2022 Jan 20. PMID: 35075333; PMCID: PMC8770992. We have two additional publications expanding this work to rapid testing of SARS-CoV2 and vaccinations (submitted publication) and quantifying the cumulative risk of SARS-CoV2 exposure of an indoor and outdoor produce worker (submitted publication). OBJECTIVE 3: Identify produce safety strategies to reduce infectious norovirus contamination on produce in the harvest and post-harvest environment that maximize public health impact. This objective was completed as described in the prior progress report and also in Sobolik JS, Newman KL, Jaykus LA, Bihn EA, LEON JS. Norovirus transmission mitigation strategies during simulated produce harvest and packing. Int J Food Microbiol. 2021 Nov 2;357:109365. doi: 10.1016/j.ijfoodmicro.2021.109365. Epub 2021 Aug 20. PMID: 34488004; PMCID: PMC8510003. As described in Objective 2, we are also developing an IDT model that will allow us to quantify the US burden based on empirical laboratory data.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Sobolik JS, Newman KL, Jaykus LA, Bihn EA, LEON JS. Norovirus transmission mitigation strategies during simulated produce harvest and packing. Int J Food Microbiol. 2021 Nov 2;357:109365. doi: 10.1016/j.ijfoodmicro.2021.109365. Epub 2021 Aug 20. PMID: 34488004; PMCID: PMC8510003.
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Sobolik JS, Sajewski ET, Jaykus LA, Cooper DK, Lopman BA, Kraay ANM, Ryan PB, LEON JS. Controlling risk of SARS-CoV-2 infection in essential workers of enclosed food manufacturing facilities. Food Control. 2022 Mar;133:108632. doi: 10.1016/j.foodcont.2021.108632. Epub 2021 Oct 22. PMID: 34703082; PMCID: PMC8532033.
- Type:
Journal Articles
Status:
Published
Year Published:
2022
Citation:
Sobolik JS, Sajewski ET, Jaykus LA, Cooper DK, Lopman BA, Kraay ANM, Ryan PB, Guest JL, Webb-Girard A, LEON JS. Decontamination of SARS-CoV-2 from cold-chain food packaging provides no marginal benefit in risk reduction to food workers. Food Control. 2022 Jun;136:108845. doi: 10.1016/j.foodcont.2022.108845. Epub 2022 Jan 20. PMID: 35075333; PMCID: PMC8770992.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
LEON JS, Jaykus LA, Sobolik JS, Cooper DK. (2021). Protecting Essential Food Workers from SARS-CoV-2 infection: A Quantitative Microbial Risk Assessment Approach. Western Regional Center to Enhance Food Safety 5th Annual Meeting. May 5, 2021. Invited Speaker.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Sobolik J, Sajeskwi E, Cooper K, Kraay A, Lopman BA, LEON JS. Protecting essential workers from COVID-19 in an indoor food processing facility: a novel integrated QMRA-IDT modeling approach. 2021 MIDAS Network Annual Meeting
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Sobolik J, Cooper D, Jaykus LA, Sajewski E, & LEON JS (2021). SARS-CoV-2 Transmission Risks and Risk Mitigation Strategies Among Essential Workers in an Indoor Food Processing Facility. International Association for Food Protection. 2021. Jul 19. Phoenix Arizona
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Cooper D, Sobolik J, Sajewski E, LEON JS. Characterizing the Risk of SARS-CoV-2 Infection Among Essential Food Workers: A Quantitative Microbial Risk Assessment Approach. International Association for Food Protection 2021. Jul 19. Phoenix Arizona
|
Progress 06/01/20 to 05/31/21
Outputs
Target Audience:Target audiences: For the past progress report period, target audiences are the trade associations representing Mexican and US produce growers, in addition to importers, distributors, retailers, and governing bodies responsible for food safety regulations. All these members of the agricultural and food safety research communities in both countries all stand to benefit from the knowledge generated by the project. To formalize the goals of the last progress report, we aimed to expand Objective 2, to protecting food workers from COVID-19 illness, given the disproportionate effect of the pandemic on this population. Thus, the target audience for this expanded objective are food workers in both the US and Mexico and their representative trade associations, and regulatory and protective government bodies in both countries as they all stand to benefit from the results and recommendations derived from this expanded objective In this reporting period, we have reached members of the agricultural and food safety research communities in both countries through informal discussions and presentation of our work at food safety meetings at the US (International Association for Food Protection) and in Mexico (Food Safety 2020 at eLatinFood 2020). We have also engaged in multiple webinars and presentations to share both norovirus and COVID-19 related information to the food and agricultural communities. We have also mentored 9 individuals in food safety ranging from a postdoctoral fellow, a professional staff member, masters students, doctoral students, and faculty, in the US. Efforts: We have specifically reached out to members of the produce community, including the Produce Marketing Association (PMA), American Frozen Food Institute (AFFI), Centers for Disease Control and Prevention (CDC), Western Regional Center to Enhance Food Safety (WRCEFS), and North Carolina State University and Mexican researchers at the Universidad Autónoma de Nuevo León, Mexico. We have four publications published, two submitted, and two under preparation. We also have multiple conference abstracts accepted and webinars. We also provide annual trainings to thesis and research students. With regards to COVID-19 outreach, we worked closely with AFFI, PMA and WRCEFS to develop guidance, outreach, and infographics to support their efforts and those of the food industry constituents they represent. Changes/Problems:Because of the impact of the pandemic, Emory University laboratories were shut down during the period of this progress report and only pandemic-related laboratory research was permitted. Laboratory work on Objective 1 was not possible. For this reason, and based on the proposed pandemic-related work described in the past progress report, we will formally request to: Expand Objective 2 of this grant to respond to the pandemic within the needs of our grant's target audience. This will not affect the proposed scope of work of the current grant. The addendum to Objective 2 focused on protecting food workers from COVID-19 illness, given the disproportionate effect of the pandemic on this population. Objective 2 would read (addendum in italics), "Develop an integrated Quantitative Microbial Risk Assessment and Infectious Disease Transmission Model that simulates the impact of norovirus contamination of produce and strategies for their control AND that simulates the impact of SARS-CoV-2 infection of essential produce food workers and prioritizes strategies for its control." Request a No Cost Extension for one additional year of the grant so we can dedicate this additional year to make-up the year lost due to the pandemic's interruption of laboratory work to advance Objective 1. What opportunities for training and professional development has the project provided?During the current reporting period, a total of 9 individuals have received professional training in project management, experimental design, modeling techniques, statistical analysis, outreach and communication, and scientific writing in food safety. Trainees included 3 masters students, 2 doctoral students, 1 postdoctoral fellow, 1 professional staff, and 2 scientists (2 faculty) during the reporting period. How have the results been disseminated to communities of interest?The products described above, including submitted peer reviewed publications and presentations at international professional conferences have all served to disseminate research results and engage communities of interest. As described in preceding sections, we have also developed webinars, presentations and infographics. For example, we partnered with the Western Regional Center to Enhance Food Safety (WRCEFS) to develop infographics, based on federal guidance, that could support the food industry in protecting their employees from COVID-19. These infographics can be found in: https://agsci.oregonstate.edu/wrcefs/covid-19-resources. They have been shared by various constituents including the Georgia Department of Agriculture, for example, in their Food Safety Division's weekly update on April 5, 2021. The results of this work have also been used directly to influence policy or practices. For example, the SARS-CoV-2 work was used by colleagues in response to proposed state policies for managing COVID-19 transmission in key agricultural food production and manufacturing workforces. These results are are also being used by AFFI to inform member guidelines. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: Now that Emory University laboratories have reopened to all research, we plan to finalize the RNAse pretreatment assay (repeat LOD experiments for both GI and GII norovirus) and begin planning experiments to validate these assays with infectious norovirus inoculum. Objective 2: We aim to publish the methodology of the successfully completed norovirus QMRA model. We also aim to submit the SARS-CoV-2 QMRA and integrated QMRA-IDT model methodologies for publication. Based on the experience derived from the SARS-CoV-2 QMRA-IDT model, we will apply it to developing a norovirus QMRA-IDT model. Using the new COVID-19 specific QMRA and integrated IDT models, we will generate novel risk estimates for COVID-19 infection of produce and food workers and derive recommendations for practices (mask use, hand hygiene, testing, symptom screening, and quarantine) to be implemented in production facilities and farms during harvest to reduce infection risk among produce workers. Objective 3: Similar to Objective 2, we aim to publish the results of the successfully completed QMRA model on the impact of agricultural practices to reduce norovirus contamination of produce.
Impacts
What was accomplished under these goals?
OBJECTIVE 1: Develop a validated laboratory method to quantify the frequency of infectious norovirus contamination in the agricultural environment. Due to the pandemic, Emory University laboratories were closed for non-essential research during this progress report period. Laboratory work on Objective 1 stopped. To formalize the goals of the last progress report, we expanded Objective 2: "Develop an integrated Quantitative Microbial Risk Assessment and Infectious Disease Transmission Model that simulates the impact of norovirus contamination of produce and strategies for their control AND that simulates the impact of SARS-CoV-2 infection of essential produce food workers and prioritizes strategies for its control." In the absence of laboratory work, we focused on the expanded Objective 2 and published a systematic review examining whether indicator organisms could be surrogates for norovirus and hepatitis A in the agricultural environment. Below is the abstract published in the International Journal of Microbiology. Title: Agricultural Detection of Norovirus and Hepatitis A Using Fecal Indicators: A Systematic Review Abstract: Indicators of fecal contamination may be used as a proxy to evaluate the potential presence of human pathogens, such as norovirus and hepatitis A, on agricultural samples. The objective of this systematic review was to determine whether the presence of human norovirus or hepatitis A was associated with microbial indicators in agricultural samples including fresh produce, equipment surfaces, and hands. Four databases (Embase, PubMed, Web of Science, and Agricola) were searched and 15 articles met inclusion and exclusion criteria. After data extraction, individual indicator-pathogen relationships were assessed using Cohen's Kappa coefficient. The level of agreement between norovirus with adenovirus was 0.09 (n= 16, 95% CI -0.05, 0.23), indicating poor agreement using Landis and Koch's criterion. Similarly, the Kappa coefficient between norovirus withE. coli(κ= 0.04,n= 14, 95% CI -0.05, 0.49) or total coliforms (κ= 0.03,n= 4, 95% CI -0.01, 0.02) was also poor. The level of agreement between hepatitis A with adenovirus (κ= -0.03,n= 3, 95% CI -0.06, 0.01) or fecal coliforms (κ= 0,n= 1, 95% CI 0, 0) was also poor. There were moderate relationships between hepatitis A withE. coli(κ= 0.49,n= 3, 95% CI 0.28, 0.70) and total coliforms (κ= 0.47,n= 2, 95% CI 0.47, 0.47). Based on these limited data, common indicator organisms are not strong predictors of the presence of norovirus and hepatitis A virus in the agricultural environment. OBJECTIVE 2: Develop an integrated Quantitative Microbial Risk Assessment and Infectious Disease Transmission Model that simulates the impact of norovirus contamination of produce and strategies for their control AND that simulates the impact of SARS-CoV-2 infection of essential produce food workers and prioritizes strategies for its control. For our Norovirus work, please see abstract below for our paper submitted to the International Journal of Food Microbiology. Title: Fresh produce contamination with human norovirus and the effect of worker practices during simulated agriculture harvest and packing processes. Abstract: In the agricultural setting, core elements of global food safety, such as hand hygiene and worker furlough, should reduce norovirus contamination risk on fresh produce. The objective of this study was to evaluate the individual and combined effect of farm-based hand hygiene and worker furlough practices on the maximum risk of norovirus infection from produce. A stochastic quantitative microbial risk assessment (QMRA) model was developed in R with two scenarios tested where a harvester and packer's norovirus infection status was: 1) assumed positive; or 2) assigned based on community norovirus prevalence estimates. In both scenarios, a harvester and packer sequentially handled one of four at-risk commodities: lettuce, tomato, raspberry, and cantaloupe. For our SARS-CoV-2 work, two important US trade organizations, the American Frozen Food Institute (AFFI) and the Produce Marketing Association (PMA) contacted our team to develop models that prioritize practices that protect their work force from COVID-19. We conducted 3 activities. 1. Understanding the context of the pandemic on the produce industry in the US and globally. We conducted structured interviews of produce facility managers to analyze the impact of the pandemic on facility productivity. We found three broad themes: shutdown of facilities, absence of workforce, unanticipated costs due to the pandemic. To understand global COVID-19 interventions to apply to our models, we screened 1,847 documents (fact sheets, guidelines, bulletins) published between January'20 -April'21, across food industries (poultry, produce, livestock, seafood), United Nations agencies (WHO, FAO), regions, and English-speaking countries. Few countries defined and prioritized essential food workers as did the U.S. or provided food industry-specific guidance. While countries' guidance was similar to that recommended by USDA-FDA-CDC-OSHA, differences were in the specific criteria for each guidance. 2. Develop QMRA models of SARS-CoV-2. In November'20, when the food industry questioned the role of surfaces in SARS-CoV-2 transmission, we showed that the surface transmission risk was very low, and the main driver was near field (< 9ft) transmission (aerosol and droplet exposures). In January'21, we shared that the new industry guidelines (masking, distancing (≥ 6ft), ventilation (2-6 air changes per hour [ACH])), combined with current Good Manufacturing Practices (cGMP, handwashing and disinfection), reduced risk of SARS-CoV-2 infection to <1% after an 8h shift for a susceptible worker exposed to an infected worker in the food production area. Considering exposures over a full day, the highest risk of SARS-CoV-2 infections to the produce workforce was in shared housing, followed by daily transportation. A combination of workforce policies (increased air exchange, handwashing, disinfection, and housing alternatives) reduced the daily risk by 86-92%. 3. Develop Integrated QMRA-IDT models of SARS-CoV-2. To leverage the population-level dynamics of Infectious Disease Transmission Model (IDT) models with the exposure assessment of QMRA models, we developed novel methodologies that integrated these two modeling approaches. Our model recommends that in a 200-worker facility, containing at least 1 infected individual, masking and 6ft distancing can be relaxed only if at least 80% of the workforce is fully vaccinated from SARS-CoV-2. OBJECTIVE 3: Identify produce safety strategies to reduce infectious norovirus contamination on produce in the harvest and post-harvest environment that maximize public health impact. Individual interventions modeled (hand hygiene and worker furlough) did not reduce produce contamination to below the norovirus infectious dose. Handwashing compliance of 100% (specifying a 2.0 log10 virus removal) did not eliminate contamination and provided an estimated range of 3.59-6.14 log10 residual viruses per commodity following the first tactile event. Combined interventions (glove use and handwashing, glove use and worker furlough, or handwashing and worker furlough) reduced viral contamination across all commodities with the largest contamination reduction resulting from 100% handwashing compliance at a maximum 6 log10 virus removal (0.39-138 residual virus). Translating produce contamination to maximum consumer infection risk, 100% handwashing with a 5 log10 virus removal was necessary to achieve an infection risk below the threshold of 0.032 infections per consumption event. This work advances the evidence-base for global produce safety standards as effective norovirus contamination control and risk mitigation strategies.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Mateo R, Lindesmith LC, Garg SJ, Gottlieb K, Lin K, Said S, Leon JS, Sims AC, Weber DJ, Baric RS, Tucker SN, Taylor DN. Production and Clinical Evaluation of Norwalk GI.1 Virus Lot 001-09NV in Norovirus Vaccine Development. J Infect Dis. 2020 Mar 2;221(6):919-926. doi: 10.1093/infdis/jiz540. PMID: 31628848; PMCID: PMC7050988.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Victor CP, Ellis K, Lamar F, Leon JS. Agricultural Detection of Norovirus and Hepatitis A Using Fecal Indicators: A Systematic Review. Int J Microbiol. 2021 Jan 4;2021:6631920. doi: 10.1155/2021/6631920. PMID: 33519936; PMCID: PMC7817235.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Franco-Fr�as E, Mercado-Guajardo V, Merino-Mascorro A, P�rez-Garza J, Heredia N, Le�n JS, Jaykus LA, D�vila-Avi�a J, Garc�a S. Analysis of Bacterial Communities by 16S rRNA Gene Sequencing in a Melon-Producing Agro-environment. Microb Ecol. 2021 Oct;82(3):613-622. doi: 10.1007/s00248-021-01709-8. Epub 2021 Feb 11. PMID: 33570667.
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Kraay ANM, Hayashi MAL, Berendes DM, Sobolik JS, Leon JS, Lopman BA. Risk for Fomite-Mediated Transmission of SARS-CoV-2 in Child Daycares, Schools, Nursing Homes, and Offices. Emerg Infect Dis. 2021 Apr;27(4):1229-1231. doi: 10.3201/eid2704.203631. PMID: 33755002; PMCID: PMC8007300.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2021
Citation:
Coralis Rodriguez, Global Health (2021) Title of Thesis: Health Communications for Migrant Produce Workers in the U.S. MPH Emory University, Atlanta GA.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2021
Citation:
D. Kane Cooper, Global Environmental Health (2021) Title of Thesis: Quantifying the Risk of SARS-CoV-2 Infection in Essential Food Workers: A Quantitative Microbial Risk Assessment Approach. MPH Emory University, Atlanta GA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Victor Courtney, Ellis Karen, Lamar Frederica, LEON JUAN. Poster Presentation at Food Safety Research at GA Food Protection, October 28 2020. Environmental Indicators for norovirus and hepatitis A virus: A systematic review. International Association for Food Protection, Virtual.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Huerta-Escobedo Andrea, Garc�a Santos, Franco-Fr�as Eduardo, LEON JUAN, Jaykus Lee-Ann, Perez Janeth, and Heredia Norma. Poster Presentation at Food Safety Research at GA Food Protection, October 28 2020. Extracellular antibiotic resistance genes in the cantaloupe farm environment. International Association for Food Protection, Virtual.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Castro-Delgado Zaira, Merino-Mascorro Jos�, Garc�a Santos, D�vila-Avi�a Jorge, Heredia Norma, LEON JUAN, Jaykus Lee-Ann, �vila-Sosa Ra�l, Sol�s-Soto Luisa. Poster Presentation at Food Safety Research at GA Food Protection, October 28 2020. Extracellular antibiotic resistance genes in the cantaloupe farm environment. International Association for Food Protection. Virtual.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
LEON JS, Diez-Gonzalez F, Garcia S. (2020). RoundTable: Foods and Emerging Pathogens: SARS-CoV-2, Norovirus and more& Food Safety 2020 at eLatinFood 2020. November 12, 2020. Invited Speaker.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
LEON JS. (2021). Presentaci�n Emory y COVID y Trabajadores Alimentarios. Presentation to Universidad Aut�noma de Nuevo Le�n. February 5, 2021. Invited Speaker.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
LEON JS. (2021). Invitation: FoodCoVNET Leadership. Presentation to FoodCoVNET at the North Carolina State University. February 22, 2021. Invited Speaker.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
LEON JS, Jaykus LA, Sobolik JS, Cooper DK. (2021). Protecting Essential Food Workers from SARS-CoV-2 infection: A Quantitative Microbial Risk Assessment Approach. North American Meat Institite VINE Meeting. March 4, 2021. Invited Speaker
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
LEON JS. (2021). Assessing SARS-CoV-2 Transmission Risks and Mitigation Practices in Food Production Environments Presenter. Presentation to the American Frozen Food Institute Board. April 20, 2021. Invited Speaker.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
LEON JS, Jaykus LA, Sobolik JS, Cooper DK. (2021). Protecting Essential Food Workers from SARS-CoV-2 infection: A Quantitative Microbial Risk Assessment Approach. Western Regional Center to Enhance Food Safety 5th Annual Meeting. May 5, 2021. Invited Speaker.
|
Progress 06/01/19 to 05/31/20
Outputs
Target Audience:Target audiences: For the past progress report period, one target communities are the main producers of jalapeno, tomato (open field) and cantaloupe melon in the north-east of Mexico where the samples were collected. More broadly are Mexican and American produce growers, importers, distributors, retailers, governing bodies responsible for food safety regulations, and members of the agricultural and food safety research communities in both countries all stand to benefit from the knowledge generated by the project. In this reporting period, we have reached members of the agricultural and food safety research communities in both countries through informal discussions and presentation of our work at food safety meetings at the US (International Association for Food Protection, University of North Carolina Chapel Hill Water and Health Conference, Georgia Association of Food Protection Annual Fall Meeting ). We have also mentored 10 individuals in food safety ranging from staff, faculty, and masters students in the US. Efforts: We have specifically reached out to members of the produce community, including the Produce Safety Alliance; US researchers at USDA, U Mass, CDC, and North Carolina State University and Mexican researchers at the Universidad Autónoma de Nuevo León, Mexico; and have collaborated with the hand hygiene industry, including GOJO Industries. We have also one publications accepted, one submitted, and two under preparation. We also provide annual trainings to thesis, laboratory, and research students. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?During the current reporting period, a total of 10 individuals have received professional training in project management, experimental design, laboratory techniques, statistical analysis, outreach and communication, and scientific writing in food safety. Trainees included 3 masters students, 2 doctoral students, 1 professional staff, 1 administrative staff, and 3 scientists (2 faculty) during the reporting period. How have the results been disseminated to communities of interest?The products described above, including submitted peer reviewed publications and presentations at international professional conferences have all served to disseminate research results and engage communities of interest. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: We plan to finalize the RNAse pretreatment assay (repeat LOD experiments for both GI and GII norovirus) and begin finalizing collaborations with our partners to test their respective infectivity assays with our norovirus stool specimens. These partners have been identified and MTAs are in place to facilitate the sharing of reagents for this work to proceed successfully. Additional experiments are also planned to evaluate the impact of our existing viral elution-concentration methods on norovirus integrity/infectivity using the RNAse pretreatment assay. Objective 2: The IDTM model will be finalized and integrated with the existing QMRA model. In addition, we will plan in parallel to expand the QMRA model with additional hand hygiene and irrigation water modules. IDTM model validation and calibration will be finalized in this next reporting period as well. Finally, given the COVID-19 pandemic, we will apply our expertise in QMRA and IDTM models to also develop COVID-specific models to assess COVID-19 risk to produce workers and the impact of existing FMSA and FDA worker health and hygiene guidelines as infection mitigation strategies. Next steps in this work include finalizing the conceptualization and model framework of the QMRA and IDTM models, complete model integration, and conduct model validation and calibration. Objective 3: The expanded QMRA & IDTM models will be used to derive additional norovirus-specific results. These will involve individual risk estimates for produce consumers attributed to enhanced hand hygiene and irrigation water practices in the agriculture production environment (QMRA model). Using the IDTM model, we will be able to assess the impact of these and other interventions at the population level in the form of cases averted among consumer and produce worker populations. Using the new COVID-19 specific QMRA and IDTM models, we will generate novel risk estimates for COVID-19 and derive recommendations for practices (mask use, hand hygiene, testing, symptom screening, and quarantine) to be implemented in production facilities and farms during harvest to reduce infection risk among produce workers.
Impacts
What was accomplished under these goals?
OBJECTIVE 1: Develop a validated laboratory method to quantify the frequency of infectious norovirus contamination in the agricultural environment. Please see the Abstract below for the assays to detect norovirus RNA on environmental samples. Using a novel paired sampling strategy, this study evaluated transmission routes of norovirus contamination on fresh produce farms and compared results to those of microbial indicators. A total of 82 composite produce rinses, 49 composite hand rinses, 27 irrigation waters, and 27 source waters were collected and processed from cantaloupe, jalapeno, and tomato farms in Nuevo Leon, Mexico. Matched produce and agricultural water samples were collected pre-harvest while matched produce and farmworker hand rinse samples were collected post-harvest, during distribution, and at packing facilities. A viral elution and polyethylene glycol precipitation method was used to concentrate viruses from samples. Norovirus RNA was detected from extracted samples using reverse transcriptase real-time PCR for norovirus GI and GII. An internal amplification control was used to assess and control for sample inhibition. Nearly half of produce rinsate samples, including 40% of cantaloupes, were presumptively positive for human norovirus. Norovirus contamination of produce was more prevalent post-harvest compared to pre-harvest (OD [95% CI] = 3.6 [1.1, 11.8]; p = 0.04). A high proportion of source water (44.4%), irrigation water (40.7%) and farmworker hand rinse samples (26.5%) were positive for human norovirus. There were no statistically significant positive correlations between norovirus and bacterial (Escherichia. coli, coliforms, Enterococcus, Bacteroidales) or viral (somatic coliphages) indicators. There was no association between presence of norovirus on produce and matched hand or agricultural water samples, however, levels of GI norovirus on produce, hands, and irrigation water samples were statistically significant using a linear mixed modeling approach. For microbial indicators, there was a clear association between produce and matched hand, but not agricultural water contamination. As transmission pathways for norovirus on produce farms differ from those of indicator organisms, it is imperative to develop evidenced-based norovirus-specific intervention strategies and policies. OBJECTIVE 2: Develop an integrated Quantitative Microbial Risk Assessment and Infectious Disease Transmission Model that simulates the impact of norovirus contamination of produce and strategies for their control. Please see abstract below for QMRA model development. Noroviruses are an important cause of produce-associated foodborne outbreaks worldwide. In the agriculture setting, core elements of global food safety regulations, such as hand hygiene and symptomatic worker furlough, may reduce norovirus risk to produce consumers, however, this has not been addressed in previous research. The objective of this study was to evaluate the impact of hand hygiene and worker furlough farm practices on consumer risk from norovirus-contaminated produce. We used a stochastic quantitative microbial risk assessment (QMRA) model developed in R with a two-dimensional Monte Carlo package. Two versions of this model represented: 1) a worst-case outbreak scenario with two norovirus-infected workers, and 2) a more realistic scenario using community-based norovirus prevalence estimates. In both scenarios, a harvester and packer, sequentially handle one of . In the outbreak scenario, individual hand hygiene interventions were equally ineffective at reducing produce contamination. Complete 100% glove compliance resulted in an average 0.62 log10 reduction. Complete 100% handwashing compliance at a 2 log10 viral removal efficacy resulted in an average 1.09 log10 reduction. Combining complete handwashing (2 log10 viral removal efficacy) with complete glove compliance increased the average log10 reduction to 1.63. Similarly, combining complete handwashing with a 6 log10 viral removal efficacy (maximum) increased the average log10 reduction to 6.00. Translating produce contamination to consumer infection risk, to reduce infection risk to below the threshold of 0.032 infections/consumption event, it was necessary to combine complete handwashing, with at least a 4 log10 viral removal efficacy, with complete glove compliance (average 0.02 risk across cantaloupe and raspberry commodities). In the more realistic model scenario, we also analyzed the impact of worker furlough. Single interventions (furlough of one symptomatic worker, hand hygiene,) resulted in nominal infection risk reductions (average risk: 0.11 cantaloupe; 0.04 raspberries) relative to no interventions (average risk: 0.12 cantaloupe; 0.04 raspberries). In contrast, combined interventions reduced the infection risk to below the 0.032 threshold. If complete handwashing, with at least a 3 log10 viral removal efficacy, was combined with either worker furlough or with complete glove compliance, the average risk ranged between 0.01-0.02 across cantaloupe and raspberry commodities. Our results recommend that combined hand hygiene and worker furlough practices, with an emphasis on handwashing, substantially reduce consumer risk from norovirus-contaminated produce. This is the first evaluation of and advances the evidence for the impact of global produce safety regulations on norovirus contamination control and risk mitigation measures. OBJECTIVE 3: Identify produce safety strategies to reduce infectious norovirus contamination on produce in the harvest and post-harvest environment that maximize public health impact. As described above, the QMRA model was used to evaluate two scenarios. The first was an outbreak with two norovirus-infected workers, who handle one of four at-risk produce commodities (cantaloupe, lettuce, tomato, and raspberries). The second was a community-prevalence based scenario, where probability of worker infection was adjusted based on community norovirus prevalence estimates. In this second scenario, the harvester and packer each had an 18% likelihood of having norovirus infection; otherwise, the workers assumed to be uninfected. The model was developed in R (version 3.4.2; R Development Core Team; Vienna, Austria) using the mc2d package for Monte Carlo simulation. For each simulation, 10,000 iterations were run, with each iteration representing 10 produce items consecutively harvested and packed using model parameters selected from defined probability distributions or assigned values. We are now also exploring the integration of this QMRA model with the Infectious Disease Transmission model.
Publications
- Type:
Journal Articles
Status:
Submitted
Year Published:
2019
Citation:
Mateo R, Lindesmith LC, Garg SJ, et al. Production and Clinical Evaluation of Norwalk GI.1 Virus Lot 001-09NV in Norovirus Vaccine Development. J Infect Dis. 2020;221(6):919-926. doi:10.1093/infdis/jiz540
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Tijerina-Rodr�guez LE, Sol�s-Soto L, Heredia N, Le�n JS, Jaykus LA, Garcia S. In House Validation of a Rinse-Membrane Filtration Method for Processing Fresh Produce Samples for Downstream Cultural Detection of Salmonella, Escherichia coli O157:H7, and Listeria [published online ahead of print, 2020 May 18]. J Food Prot. 2020;10.4315/JFP-19-581. doi:10.4315/JFP-19-581
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Prince-Guerra JL, Nace ME, Lyles RH, et al. Both Handwashing and Alcohol-Based Hand Sanitizer Reduce Soil and Microbial Contamination on Farmworker Hands During Harvest - But Produce Type Matters [published online ahead of print, 2020 Jul 17]. Appl Environ Microbiol. 2020;AEM.00780-20. doi:10.1128/AEM.00780-20
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Victor C, Ellis K, Lamar F, LEON J. Poster Presentation at UNC Water and Health Conference 2019 Oct 7-11 2019. Environmental Indicators for norovirus and hepatitis A virus: A systematic review. Raleigh, North Carolina.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Victor C, Ellis K, Lamar F, LEON J. Georgia Association of Food Protection Annual Fall Meeting 2019 Sep 16, 2019. Environmental Indicators for norovirus and hepatitis A virus: A systematic review. Athens, Georgia
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2020
Citation:
Rachel Usher, Epidemiology (2020) Title of Thesis: Characterizing relationships between bacterial indicators of foodborne pathogens on Mexican produce in the pre-harvest and post-harvest environment. MPH Emory University, Atlanta GA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Sobolik J, Newman K, Jaykus LA, LEON JS. Hand hygiene interventions to reduce norovirus contamination of ready-to-eat fresh produce during produce harvesting and packing on farms. 2018 International Association for Food Protection Meeting, Salt Lake City, UT. ID#18294.
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