MI008-06 Prevalence and characterization of norovirus in sporadic foodborne disease infections

Outbreak investigations have shown the importance of viral agents in causing approximately 50% of U.S. outbreaks of waterborne and foodborne enteric disease, but little information exists reagrding sporadic cases of acute gastroentritis (AGE). Our www.ReportFoodPoisoning.com web site (RFP) provides us a means for identifying sporadic AGE cases within hours of clinical onset so that volunteers can be contacted for provision of an immediate early-onset fecal specimen and follow-up specimens at 1 and 2 weeks.  Using RFP, we will study 100 sporadic (non-outbreak) norovirus cases and make comparisons to 100 or more outbreak-associated norovirus strains maintained on CDC’s CaliciNet database. This research will determine if particular strains of norovirus are more likely to be associate with outbreaks rather than sporadic cases.  We will also determine if the strains of norovirus differ with respect to duration of shedding or if RT-PCR detection of some strains is more severely impaired by delayed collection of diagnostic specimens. By re-sampling at 1 and 2 weeks after initial norovirus detection, we will produce critical information regarding the duration of virus shedding that may lead to a lengthening (or shortening) of the standard recommendations that food service and health care workers should refrain from working for 2-3 days post clinical recovery.
Additionally, this research will enable a descriptive epidemiologic study of Clostridium difficile carriage among sporadic cases of community-acquired AGE.Isolates of C. difficile obtained in this study will be compared via PFGE analysis with outbreak and hospital-associated isolates available at the CDC.