May 2005 FDA Sprout Public Meeting 1 of 12 Risk Analyses: Using a risk-based approach to study sprout safety Don Schaffner, Ph.D. Professor and Extension Specialist Rutgers - The State University of NJ

May 2005 FDA Sprout Public Meeting 2 of 12 Why are we interested? -Initial discussion with Bob Sanderson regarding using irrigation water testing -Can Monte Carlo simulation be used? -Rebecca Montville begins to survey the literature

May 2005 FDA Sprout Public Meeting 3 of 12 Our published papers -Montville, R. I. and Schaffner, D.W Analysis of published sprout seed disinfection studies shows treatments are highly variable. Journal of Food Protection. 67(4):758–765. -Montville, R. I. and Schaffner, D.W Monte Carlo simulation of pathogen behavior during the sprout production process. Applied and Environmental Microbiology. 71(2): 746–753.

May 2005 FDA Sprout Public Meeting 4 of 12 Summary of seed disinfection 20,000 ppm literature

May 2005 FDA Sprout Public Meeting 5 of 12 Effect of inoculum size on log reduction

May 2005 FDA Sprout Public Meeting 6 of 12 Summary of different disinfection techniques

May 2005 FDA Sprout Public Meeting 7 of 12 Analytica screen snapshot

May 2005 FDA Sprout Public Meeting 8 of 12 If prevalence is high, testing is more effective If prevalence is low, disinfection is more effective More samples = testing is more effective More data on prevalence is needed!

May 2005 FDA Sprout Public Meeting 9 of 12 Number of samples matters!

May 2005 FDA Sprout Public Meeting 10 of 12 Lessons learned -Seed disinfection is a highly variable process, even in the laboratory -Seed (irrigation water) sampling can be highly effective Test many (hundreds) of sub-samples prior to using the seed in production Test irrigation water during production -Disinfection and sampling are complementary tools

May 2005 FDA Sprout Public Meeting 11 of 12 Closing thoughts on risk assessment models -All models are wrong… but some are useful George Cox -An approximate answer to the right problem is worth a good deal more than an exact answer to an approximate problem John Tukey

May 2005 FDA Sprout Public Meeting 12 of 12 Cartoon