Source: Illinois Institute of Technology submitted to
INVESTIGATION OF NOROVIRUS CROSS-CONTAMINATION DURING FOOD SERVICE PROCEDURES USED IN THE PREPARATION OF FRESH PRODUCE
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
EXTENDED
Funding Source
OTHER GRANTS
Reporting Frequency
Annual
Accession No.
0214236
Grant No.
2008-51110-04345
Project No.
ILLW-2008-01574
Proposal No.
2008-01574
Multistate No.
(N/A)
Program Code
111
Project Start Date
Sep 1, 2008
Project End Date
Sep 30, 2012
Grant Year
2008
Project Director
Lee, A.
Recipient Organization
Illinois Institute of Technology
3300 S FEDERAL ST RM 201
Chicago,IL 60616-3792
Performing Department
(N/A)
Non Technical Summary
According to the Centers for Disease Control & Prevention, human enteric viruses are estimated to cause two-thirds of the foodborne illness in the U.S. each year, with the great majority of those attributed to norovirus (NoV). Fruits and vegetables have increasingly been implicated as vehicles for NoV gastroenteritis. Such foods may become contaminated at the source, in a farm setting, during processing, in the home or food service kitchen during preparation, or during serving by infected food handlers or patrons. The goal of this proposal is to examine cross-contamination of NoV during common procedures used in preparation of fresh produce and evaluate the risk reduction after workers' exposure to educational materials developed as a result of the research findings. NoV transfer data will be collected using murine NoV (MNV-1) as a surrogate for human NoV (HNV) between hands, fresh produce items, knives and cutting boards. In some cases, HNV transfer data will also be collected and compared with MNV-1 transfer data. The ability of handwashing and gloves to prevent or reduce virus transfer from hands during food preparation will also be examined. Cross-contamination data generated in this study will be incorporated into a quantitative risk assessment, which may be used to determine risk management strategies that will have an impact on reducing the contamination of fresh produce food items in foodservice settings. Results will be communicated to food safety professionals and foodservice operators, with an evaluation of risk reduction based on behavioral change.
Animal Health Component
(N/A)
Research Effort Categories
Basic
20%
Applied
50%
Developmental
30%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
7121499110120%
7124030104010%
7124030110130%
7124030209020%
9036099303020%
Knowledge Area
903 - Communication, Education, and Information Delivery; 712 - Protect Food from Contamination by Pathogenic Microorganisms, Parasites, and Naturally Occurring Toxins;

Subject Of Investigation
1499 - Vegetables, general/other; 4030 - Viruses; 6099 - People and communities, general/other;

Field Of Science
3030 - Information and communication; 1101 - Virology; 2090 - Statistics, econometrics, and biometrics; 1040 - Molecular biology;
Goals / Objectives
The objectives have been determined by considering the flow of fresh produce in a typical foodservice operation, and by identifying the most important points for transfer of norovirus (NoV) from humans to food and food preparation surfaces. Develop efficient methods to recover and detect human norovirus (HNV) and murine norovirus (MNV-1) from food preparation surfaces by quantitative RT-PCR (qRT-PCR) techniques. Collect transfer data for MNV-1 between surfaces including knives, cutting boards and stainless steel surfaces common in foodservice procedures used in preparation of fresh produce, and in some cases using co-inoculated HNV and MNV-1, such that MNV-1 data can be used as a surrogate for HNV in the risk assessment. Collect transfer data for MNV-1 between hands and surfaces common in fresh produce preparation, including an evaluation of the effectiveness of hand washing procedures to prevent or reduce MNV-1 transfer, and evaluation of the effect of gloved vs. ungloved hands on the transfer rate. Collect spread and transfer data for co-inoculated HNV and MNV-1 from a single produce item to others during a food-preparation process, e.g. salad preparation and mixing, such that MNV-1 data can be used as a surrogate for HNV in the risk assessment. Calculate appropriate virus transfer and reduction rates, and incorporate this information into a quantitative risk assessment using discrete event simulation modeling software. Develop educational materials based on research findings and evaluate material effectiveness through onsite food safety observational studies and risk modeling. Research findings will also be disseminated via education programs (including on campus teaching, short courses, seminars, webinars, and presentation of research findings at scientific meetings). Evaluate the impact of outreach and training methods on behavioral change at the food service establishment level.
Project Methods
A multi-institution team has been assembled consisting of researchers from Illinois Institute of Technology (IIT) National Center for Food Safety and Technology (NCFST) and Rutgers University as well as collaborators from the U.S. Food and Drug Administration (FDA) Center for Food Safety and Applied Nutrition and Ecolab USA. The goal of the proposed study is to examine cross-contamination of norovirus (NoV) during common foodservice procedures used in preparation and service of fresh produce, incorporate NoV transfer data into a quantitative risk assessment, and evaluate the risk reduction after workers exposure to educational materials developed as a result of the research findings. The study will address cross-contamination concerns in the preparation of fresh produce commonly used in salad preparation, using three representative commodities: whole red tomatoes, romaine lettuce and green onions. NoV cross-contamination during the preparation of fresh produce and the transfer of viral particles via human contact to clean produce will be investigated. MNV-1 will be used where direct human contact (via human subjects) is required in the experimental protocol. MNV-1 will also be used to investigate the transfer of viral particles between various environmental and food preparatory surfaces and in some of the experiments the transfer rates will be correlated to that of HNV. The data generated will be incorporated into a quantitative risk assessment, which will be used to develop risk management strategies designed to reduce the contamination of fresh produce food items during foodservice preparation, and the results will be broadly communicated to food safety professionals and foodservice operators, with an evaluation of risk reduction based on behavioral change. The extension proposed in this study will be disseminated via short courses, other educational programs and industry meetings, ensuring both the fresh produce industry and the foodservice industries benefit from this research.

Progress 09/01/09 to 08/31/10

Outputs
OUTPUTS: To date, development of a qRT-PCR for the quantification of human NoV and murine NoV has been established and undergoing optimization. The transfer scenerios approved by IIT Human Ethics has been completed. Therefore, objectives #1, 2, 3 and 4 are now completed. The IIT/FDA team is readying for data transfer to Rutgers University along with data collected by EcoLab team for model development. ALthough education materials are still in development, dessimination of information has been conducted at scientific conferences e.g. IAFP and there will be another symposium being organized at IAFP 2012. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: A six month no-cost extension was sought and granted due to unexpected delays with both IIT and FDA IRB due to reporting of an adverse event that occured during the volunteer trials. The project team was cleared and that the adverse event reported was not a result of the project. The project team had to cease work while the respective IRB completed their investigation.

Impacts
The use of simplex qRT-PCR to detect murine or human NoV is frequently conducted along with a standard curve for virus quantification. A duplex qRT-PCR assay that simultaneously detects these two targets is currently under evaluation in our laboratory. However, the detection efficiency of one of the targets is less efficient using the duplex assay. Additional efforts to optimize the duplex reactions are underway and may include manipulation of the MgCl2 and polymerase enzyme concentrations. Due to the limited amount of human NoV stock available and training for the new personnel/students on this project, extra precautions have been taken, therefore, progress has been slower than planned. However, once the duplex assay is optimized, data collection will be quick and allow cost and time savings. The target date is proposed to be extended to March 2012. To date, 120 individual volunteer events have been performed, including the transfer of murine norovirus (MNV-1) in both directions between hands and gloves to/from fresh-cut romaine lettuce leaves. Gloves under investigation include polyvinyl, vinyl and nitrile gloves. In addition, transfer of MNV-1 between surfaces while chopping romaine lettuce is also under investigation. Initial results suggest that transfer is greater from gloved hands to lettuce compared to bare hands, but that transfer from contaminated lettuce to bare hands occurs more readily than to gloved hands. The literature search for workers' behaviors is currently being collected. The transfer rates of virus data collected from IIT/IFSH is currently being analyzed. A preliminary quantitative microbial risk assessment (QMRA) for NoV transfer from foods and from workers has been developed. Current work is focused on refining and expanding the QMRA as new transfer data are being collected. In addition, worker variability and virus survival data are being considered, using discrete event modeling in Arena software. EcoSure is gathering information from two different sources. A survey was sent out to major quick-service and full-service chains to understand current practices concerning pre-prepped vs. whole produce practices, equipment used and training methods. Eighteen chains responded representing approximately 15,600 restaurant units. Additional questions are being formulated to be sent for additional information as requested by the Institute for Food Safety and Health. In addition, EcoSure is analyzing data from their third party food safety evaluations that took place between 2006 and 2010. EcoSure will be looking at various food safety questions relevant to potential NoV cross-contamination evaluated during the food safety audits and will analyze the data using various criteria such as quick serve vs. full serve, time of day, day of week, and frequency of participation in a food safety program. Additionally survey questions will be shared with IFSH (FDA Moffett/IIT) when available.

Publications

  • A. Suriyanarayanan, B. Puli, S.F. Grove and A. Lee. (2010) Development of Optimal Methods for Recovery of Murine Norovirus From Surfaces Common in the Preparation of Fresh Produce. International Association for Food Protection Annual Meeting 2010 (Anaheim, CA), Aug. 2010.(Poster Presentation)
  • T.Y Chang and Y.C. Shieh. (2010). Recovery and Survival of Murine Norovirus on Inoculated Lettuce and Tomato Salad Mix. International Association for Food Protection Annual Meeting 2010 Anaheim, CA), Aug. 2010. (Poster Presentation)
  • A. Lee. (2010). Norovirus cross-contamination during food service procedures used in the preparation of fresh produce. International Association for Food Protection Annual Meeting 2010 (Anaheim,CA), Aug. 2010. (Oral Presentation)
  • A. Lee and S. Grove. (2011). Intervention Strategies to Control Foodborne Viruses During Processing and Handling. National Shellfish Association Annual Meeting 2011 (Baltimore, MD). Mar 2011. (Oral Presentation)
  • T.-Y. Chang, G. Fleischman, and Y. C. Shieh. (2011). Norovirus Cross-contamination during Tomato Slicing Using Hand Knife and Commercial Slicer. American Society for Microbiology Annual Meeting 2011 (New Orleans, LA) (Poster Presentation)


Progress 09/01/08 to 08/31/09

Outputs
OUTPUTS: Human norovirus (NoV) is commonly transmitted by person-to-person spread, and many outbreaks of NoV may be linked to the preparation of food by infected food handlers. Salad preparation surfaces are of particular concern because the product often does not undergo an intervention step prior to consumption. In this study, methods for inoculation and recovery of murine norovirus (MNV-1), a NoV surrogate from food preparatory surfaces were optimized. Similarly, methods for the quantitation of viruses were optimized using a rapid molecular assay and results compared to traditional infectivity assays. The methods being developed and optimized will serve as a foundation for upcoming cross contamination studies which will in turn lead to the development of a risk assessment model for NoV transfer within the food service setting. The team has completed objective 1 of the project plan and on track to complete objective 2 - collection of transfer data for MNV-1 between surfaces including knives, cutting boards and stainless steel surfaces. The time spend on these methods are critical in that future transfer experiments will use one universal method and was important to access recovery rates from methods developed at NCFST and other researchers. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

Impacts
The current results have been shared and discussed with the various project teams. For example, Rutgers has made some preliminary studies for transfer model development using the data obtaind by NCFST. This will allow the various project team to refine experimental protocols to ensure the relevant data are collected. EcoLab has started conducted survey and quantifying food establishments that will participate in the study and feed information back to the project teams. The survey include the use of various types of gloves, produce items currently used in various food establishments, equipment and cutting implements. The early start for EcoLab has provided valuable information to the team ensuring that the experiment protocols reflect actual conditions used by industry. NCFST has obtained final IRB approval for human volunteer studies and on track to recruit volunteers to conduct transfer studies. The methods developed from this project thus far, allowed for an assessment of recover methods for viruses. Recovery rates varied widely and the project team was able to use the information in method selection and refinement to ensure consistent recovery of viruses. Through FDA Cooperative Agreement and NCFST, additional lab resources such as equipment and additional graduate student were added onto the project.

Publications

  • One poster was presented by Rutgers at IAFP 2009. Two abstracts from NCFST was submitted to IAFP 2010.