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The goal of the project is to improve methods and technologies that will facilitate a reduction in the number of foodborne illnesses due to viral pathogens. Specifically, new methodologies for concentrating, recovering and detecting human noroviruses and Hepatitis A viruses from foods will be developed so that screening potentially contaminated food items will be possible. Novel intervention strategies for controlling or eliminating viruses from foods or the hands of foodworkers will also be explored so that recommendations for virus inactivation can be made. Lastly, unique infectivity models for human norovirus will be evaluated to establish a means of distinguishing between infectious and non-infectious viruses recovered from foods.
NON-TECHNICAL SUMMARY: Human noroviruses have emerged as the most common cause of outbreaks of food-related illnesses in the United States. Hepatitis A Virus (HAV) has also been associated with numerous outbreaks of food-related illnesses and its disease burden may be underestimated. Current methods for detecting viruses in foods are not adequate and cannot discriminate between infectious and non-infectious virus. Since human noroviruses and most strains of HAV cannot be grown in the lab, researchers use model viruses to estimate the infectivity of these viruses. Improvements in methodologies for virus detection and discrimination of infectious and non-infectious virus, and technologies for virus inactivation through chemical or physical intervention strategies are needed to facilitate a reduction in the number of foodborne illnesses due to viral pathogens. This project specifically addresses these needs by developing rapid screening technologies for virus recovery and detection in foods, investigating novel intervention technologies for virus inactivation using model viruses, and evaluating unique models for distinguishing between infectious and non-infectious viruses recovered from foods. The results of this study will make possible, the rapid screening of foods potentially contaminated with viruses and assessment of the risk posed by consumption of foods contaminated with infectious virus. Furthermore, with knowledge about the efficacy of intervention strategies for virus inactivation, recommendations for food or hand decontamination or sanitation can be made. The results of this study will improve the science leading to a reduction of food-related illnesses due to viruses and will be of particular interest to food production, food processing and food service industries.
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APPROACH: Viruses and cells will either be purchased (ATCC) or obtained from research collaborators (CDC, SCDHEC, Washington Univ.). Unique methodologies for high-throughput screening of chemical compositions of virus adsorption/elution buffers will be developed so that optimized protocols can be developed for virus recovery from foods. To do this, standard virus culture and quantification protocols or quantitative (real-time) RT-PCR assays will be adapted to the 96-well format. Chemical and physical intervention strategies will be investigated either in solution or by surface exposure followed by standard virus culture methods. As previously published, unique infectivity models will be evaluated using a histo-blood group antigen ligand-binding assay followed by realtime RT-PCR. Detecting virus inactivation by the novel methods will be compared to detecting virus inactivation by standard cell culture methods. For other experiments, outcomes will be measured by comparison to controls.