Is norovirus a foodborne or pandemic pathogen? An analysis of the transmission of norovirus-associated gastroenteritis and the roles of food and food handlers.

This study examined the association of norovirus with foodborne disease outbreaks linked to food handlers and foodborne outbreaks of acute gastroenteritis associated with norovirus, in comparison to Salmonella foodborne gastroenteritis. Comparative analysis using chi(2)-tests showed no similarity between the outbreaks from norovirus and those from Salmonella. Odds ratios also showed a stronger similarity between the proportions of food handler-implicated norovirus outbreaks than from Salmonella-implicated outbreaks. An analysis of data found norovirus transmission to occur more frequently spread person-to-person, unlike Salmonella, but similar to influenza or rotavirus. Norovirus was also not shown to be associated with food consumption. The data collection tool that focuses on food handlers as a source of the virus may be better including the general human population. Such an enteric virus would be better understood through its similarity to the person-to-person transmission model resulting in pandemic spread.

Salmonella Enteritidis in meat, poultry, and pasteurized egg products regulated by the U.S. Food Safety and Inspection Service, 1998 through 2003.

The U.S. Food Safety and Inspection Service (FSIS) tests for Salmonella in meat, poultry, and egg products through three regulatory testing programs: the Pathogen Reduction-Hazard Analysis and Critical Control Point (PR-HACCP) program, the ready-to-eat program for meat and poultry products, and the pasteurized egg products program. From 1998 through 2003, 293,938 samples collected for these testing programs were analyzed for the presence of Salmonella enterica serotypes. Of these samples, 12,699 (4.3%) were positive for Salmonella, and 167 (1.3%) of the positive samples (0.06% of all samples) contained Salmonella Enteritidis. The highest incidence of Salmonella Enteritidis was observed in ground chicken PR-HACCP samples (8 of 1,722 samples, 0.46%), and the lowest was found in steer-heifer PR-HACCP samples (0 of 12,835 samples). Salmonella Enteritidis isolates were characterized by phage type, pulsed-field gel electrophoretic pattern, and antimicrobial susceptibility. Phage typing of 94 Salmonella Enteritidis isolates identified PT13 (39 isolates) and PT8 (36 isolates) as the most common types. One isolate from a ready-to-eat ham product was characterized as PT4. Electrophoretic analysis of 148 Salmonella Enteritidis isolates indicated genetic diversity among the isolates, with 28 unique XbaI electrophoretic patterns identified. Of these 148 isolates, 136 (92%) were susceptible to each of 16 antimicrobials tested. Two isolates were resistant to ampicillin alone, and 10 isolates were resistant to two or more antimicrobials. Isolation of Salmonella Enteritidis from FSIS-regulated products emphasizes the need for continued consumer education on proper food handling and cooking practices and continued work to decrease the prevalence of Salmonella in meat, poultry, and pasteurized egg products.

Indicator organisms in meat and poultry slaughter operations: their potential use in process control and the role of emerging technologies.

Measuring commonly occurring, nonpathogenic organisms on poultry products may be used for designing statistical process control systems that could result in reductions of pathogen levels. The extent of pathogen level reduction that could be obtained from actions resulting from monitoring these measurements over time depends upon the degree of understanding cause-effect relationships between processing variables, selected output variables, and pathogens. For such measurements to be effective for controlling or improving processing to some capability level within the statistical process control context, sufficiently frequent measurements would be needed to help identify processing deficiencies. Ultimately the correct balance of sampling and resources is determined by those characteristics of deficient processing that are important to identify. We recommend strategies that emphasize flexibility, depending upon sampling objectives. Coupling the measurement of levels of indicator organisms with practical emerging technologies and suitable on-site platforms that decrease the time between sample collections and interpreting results would enhance monitoring process control.