Gary P. Richards, Ph.D. - Comment

I am pleased to have this opportunity to provide comments and scientific data that you have requested for the proposed “Risk Assessment on Norovirus in Bivalve Molluscan Shellfish”, Docket no. FDA-2011-N-0002. I have been conducting norovirus research for the past 25 years and hope that the information presented will be of benefit. As I reviewed the Request for Comments and for Scientific Data and Information, I was concerned with the plan to use “enteric virus surrogates” in the risk assessment. I am also concerned about the inability to differentiate infectious from inactivated noroviruses and the underreporting of norovirus illnesses in the general population. All of these drawbacks will make it very difficult if not impossible to develop a valid risk assessment model. Due to space limitations here, I have included as an attachment more on my specific concerns. I have also included two papers that I published. One gives credible scientific evidence that norovirus surrogates do not mimic the response of human norovirus under most environmental or processing conditions. The second paper documents the inability to differentiate infectious from inactivated noroviruses using current-day testing methods. In my opinion, completion of a scientifically valid risk assessment on noroviruses will not be possible given the concerns expressed above and in the supporting documentation.