Comparisons of microbiological evaluations of selected kitchen areas with visual inspections for preventing potential risk of foodborne outbreaks in food service operations

Most local health departments utilize visual, but not microbiological, methods when inspecting food service operations. To evaluate the marginal utility of microbial testing for minimizing potential risks of foodborne outbreaks in restaurants, swab samples were taken from handwashing sink faucets, freshly cleaned and sanitized food-contact surfaces, and from cooler or freezer door handles in 70 of 350 category-three (high-risk) food service operations in Toledo, Ohio. The swabs were inoculated onto different selective media, and standard procedures were used to identify pathogenic and nonpathogenic bacteria. Microbiological evaluations of the sampled food service operations were compared with visual inspection reports, using a numeric rating scale. Enteric bacteria (that may indicate fecal contamination) were found on food contact surfaces, on cooler or freezer door handles, and on handwashing sink faucets in 86, 57, and 53% of the food service operations, respectively. Approximately 27, 40, and 33% of the restaurants received visual ratings of very poor to poor, fair, and good to very good, respectively. In comparison, 10, 17, and 73% of the restaurants received microbiological rating scores of very poor to poor, fair, and good to very good, respectively. Restaurants with trained personnel received significantly higher visual rating scores than restaurants without trained personnel (P < 0.01). Although more restaurants received poor rating scores by visual inspection than by microbiological evaluation, the presence of fecal bacteria from different sites in more than 50% of the food service operations indicated that visual inspection alone might not be sufficient for minimizing potential risk for foodborne disease outbreaks. Therefore, we recommend periodic microbiological evaluation of high-risk food service operations, in addition to visual inspection, for minimizing the risk of foodborne disease outbreaks.