1. Outbreak of Norovirus Associated with Gulf Coast Oysters, TN, 2009 Sarah Hill and Margaret Zylstra Tennessee Department of Health, Chattanooga- Hamilton County Health Department

2. Norovirus Common Low infectious dose Human fecal pathogen Contaminates fresh and marine waters Environmentally stable

3. Not the reservoir for norovirus Filter water over gills and mantle, 5 L/h Viruses and bacteria Frequently consumed raw

4. Public Health Investigation Outbreak? –3/9, 3 ill persons call CHR report eating raw oysters at Restaurant A Environmental investigation –Facility inspected –Score of 83, one critical violation Chicken salad holding at 45° F rather than <41° F All oyster storage and serving was adequate –Raw oysters (n=24) and tags collected from restaurant

6. Investigation Results Case definition: Person who developed vomiting and/or diarrhea within 3 days of eating at Restaurant A 3/5-3/7 13 ill identified and 30 controls enrolled 4 confirmed norovirus genogroup 1 Cases from TN, AL, GA, MO No ill restaurant staff Oysters: negative for norovirus

7. A2C oysters consumed at Restaurant A

8. FoodOR95% CIP value Raw Oysters10810-1147<0.0001 Fried Oysters0.50.1-5.40.6 Fire-roasted Oysters 0.10-1.80.04 Salad1.20.3-5.10.8 Other entrée0.10-0.40.0007

9. Actions 3/14 CHR and Tennessee DOH inform FDA of epi association Mississippi Dept of Marine Resources –3/17 closed harvest area –Recalled 2/24 harvest –Recommended cooking oysters harvested 2/25-3/17 Tennessee (3/20) and FDA (3/21) advised consumers to avoid oysters harvested 2/25-3/17

10. Discussion

11. Surveillance and rapid investigation, cooperation of Restaurant A key Epi data v. lab data Mississippi investigating illness reports Mississippi Dept of Marine Resources has requested FDA assistance to evaluate potential sources of contamination

12. Questions? Tennessee Department of Health Communicable and Environmental Diseases 1 st Floor, Cordell Hull Building 425 5 th Avenue North Nashville, TN 3724 615.741.7247