Health department inspection criteria more likely to be associated with outbreak restaurants in Minnesota.

Millions of routine restaurant inspections are performed each year in the United States, and the Centers for Disease Control and Prevention has reported that a majority of foodborne illness outbreaks occur in restaurant settings. In an attempt to relate the data collected during inspections in Minnesota to illness likelihood, data from routine inspections conducted at outbreak restaurants were compared with data from routine inspections conducted at nonoutbreak restaurants. The goal was to identify differences in recorded violations. Significantly more violations were recorded at restaurants that had outbreaks. The majority of these violations were related to contamination in the facility and environment and to food handling procedures. Relative risks also were calculated for violations significantly more likely to occur at locations that had outbreaks of norovirus infection, Clostridium perfringens infection or toxin-type illness, and Salmonella infection. These three pathogens are estimated to cause the majority of foodborne illnesses in the United States. Meta-analysis of composited data for the three pathogens revealed 11 violations significantly more likely (α < 0.05) to be identified during routine inspections at outbreak restaurants than during inspections at nonoutbreak restaurants. Application of this information permits assessment of health department inspection data in a consistent fashion. This approach can help identify criteria more likely to be associated with outbreak locations and allow operators to focus on interventions that will have the most significant impact in higher risk establishments.

Using a theoretical predictive tool for the analysis of recent health department inspections at outbreak restaurants and relation of this information to foodborne illness likelihood.

Because U.S. restaurants are inspected at least annually against criteria in the U.S. Food and Drug Administration Model Food Code, large amounts of data are generated and should be systematically reviewed. The purpose of this study was to determine the relationships among the data obtained through health department inspections, the contributing factors to foodborne illness identified by the Centers for Disease Control and Prevention, and the risks of outbreaks of norovirus, Salmonella, and Clostridium perfringens infection associated with a specific restaurant. These agents were chosen for the analysis because they cause the majority of foodborne illnesses. A theoretical predictive assessment tool was built that extracts data from routine health department inspection reports for specific restaurants to establish a risk profile for each restaurant and identify the likelihood of a norovirus, Salmonella, or C. perfringens outbreak at that restaurant. The tool was used to examine inspection reports from restaurants known to have had confirmed norovirus, Salmonella, and C. perfringens outbreaks. Although evaluation of an extensive data set revealed lack of an overall association between outbreak inspection scores and routine inspection scores obtained at outbreak restaurant locations, certain specific violations were significantly more likely to be recorded. Significant differences in types of violations recorded during outbreak and routine inspections were determined. When risks based on violation type can be identified, targeted actions may be able to be prioritized and implemented to help decrease illnesses.

Clostridium botulinum Toxin Formation in Romaine Lettuce and Shredded Cabbage: Effect of Storage and Packaging Conditions.

The potential for growth and toxin production by Clostridium botulinum spores was investigated in samples of fresh-cut romaine lettuce and shredded cabbage packaged in vented and nonvented flexible pouches at storage temperatures of 4.4, 12.7, and 21°C for up to 28 days. One hundred grams of cut, washed romaine lettuce and cabbage were placed in polyester bags. Approximately 104 heat-shocked spores were added per package. Before sealing, half the packages were vented. No toxin was detected with either storage method at 4.4 and 12.7°C. In nonvented pouches of romaine lettuce at 21°C, spores grew and produced toxin after 14 days. Romaine samples at 21°C in vented pouches became toxic after 21 days, indicating formation of anaerobic microenvironments within the pouches. In nonvented packages of cabbage at 21°C, toxin was detected after 7 days. All toxin-positive samples were judged to be inedible prior to toxin detection.

Simultaneous Growth of Listeria monocytogenes and Listeria innocua.

Listeria spp. have been isolated from a wide variety of sources, and in many situations Listeria innocua is more commonly found than Listeria monocytogenes . Growth of three L. monocytogenes strains was studied when inoculated simultaneously with a rhamnose negative L. innocua strain into culture media and cheese sauce. Fraser broth (FB), Trypticase™ soy broth plus 0.6% yeast extract (TSB-YE), University of Vermont medium (UVM) modified Listeria enrichment broth, and cheese sauce were inoculated (ca. 102 cells per ml) and incubated for 24 h; FB, TSB-YE, and cheese sauce at 35°C, UVM at 30°C. Growth of four rhamnose-positive, L. innocua strains was also studied in culture media. Growth of L. monocytogenes was similar to that for L. innocua in TSB-YE or cheese sauce. However, in FB and UVM, L. innocua populations were significantly higher than L. monocytogenes . This occurred when media were inoculated individually or simultaneously. This may explain in part why L. innocua is isolated more frequently than L. monocytogenes from foods and environmental samples.