Food Safety Projects

Completed Projects

General Public
Beliefs About Sources of Gastrointestinal Illness Population Study

Policies and Practices in Retail Food Service Establishments
Egg Handling Practices Study
Evaluation of Outbreak and Nonoutbreak Restaurants
Food Workers’ Food Preparation Practices Focus Group Study
Food Workers’ Food Preparation Practices Population Study
Ground Beef Handling Practices Study
Hand Hygiene Study
Tomato Handling Practices Study

Retail Food Safety Programs
Environmental Health Specialists’ Inspection and Outbreak Investigation Practices Focus Group Study
Manager Certification and Inspection Scores Study

Projects in Progress

Chicken-Handling Practices Study
Cooling Study
Environmental Surface Sampling Study
Food Allergens Study
Foodborne Illness Complaint System Project
Foodborne Illness Outbreak Study
Ill Food Worker Study
Kitchen Manager Certification Study
Leafy Greens Study
Microwave Use Study

Completed Projects

Beliefs About Sources of Gastrointestinal Illness Population Study
Objective: To increase understanding of the population’s experiences with and beliefs about gastrointestinal illness.

Study Results: A telephone survey of randomly selected U.S. residents revealed that: 22% of respondents believed their recent gastrointestinal illness resulted from a specific meal eaten outside the home; respondents who experienced mild symptoms were more likely to attribute their illness to a meal eaten outside the home; respondents tended to use some of the same reasons, such as symptom timing and illness of their meal companions, for attributing illness to a specific meal as epidemiologists do; only 8% of respondents reported their illness to a health department or suspected restaurant; and most respondents who attributed their illness to a specific outside meal said their illness symptoms began within a short time (5 hours) of eating that meal. These results suggest that education efforts should focus on the nature and timing of foodborne illness symptoms and the importance of reporting suspected foodborne illnesses.

Publications and Presentations

Egg-Handling Practices Study
Objective: To identify the prevalence of high-risk egg-handling practices and establishment policies in restaurants that serve breakfast all day.

Study Results: Interviews and observations conducted in restaurants that prepare eggs revealed that risk egg handling practices were common. Fifty-four percent of restaurants pooled raw shell eggs not intended for immediate service. These pooled eggs were held a median of 4 hours for scrambled eggs, 5.5 hours for omelets, and 6 hours for pancakes and French toast. Nearly 26% of restaurants reported storing eggs at room temperature. Employees reported sanitizing utensils used to prepare eggs less than once every 4 hours in 42% of restaurants. However, eggs were generally cooked to 72 to 83ºC, which is above the recommended final cook temperature of 63 to 68ºC.

Publications and Presentations

Environmental Health Specialists’ Inspection and Outbreak Investigation Practices Focus Group Study
Objective: To evaluate the knowledge, attitudes, and behaviors of environmental health specialists regarding inspections and outbreak investigations.

Study Results: Focus group results concerning inspections indicated that environmental health specialists thought that identifying and correcting critical violations of food safety regulations, educating restaurant workers and managers about these critical violations, and developing a good relationship with restaurant managers were common and important inspection activities. Specialists also identified inspection difficulties associated with the restaurant industry, the inspection structure, and environmental health management.

Results concerning outbreak investigations revealed substantial variability in the type of activities in which participants engaged during investigations, and the amount and nature of the collaboration between epidemiology and environmental health during investigations. Also, many participants indicated that they did not often identify contributing factors to outbreaks during investigations. Participants also identified several difficulties associated with outbreak investigations, including those associated with restaurant employees, restaurant customers, and environmental health organizations.

Publications and Presentations

Evaluation of Outbreak and Nonoutbreak Restaurants
Objective: To identify pathogens and contributing factors associated with restaurant-related foodborne illness outbreaks and food-safety differences between outbreak and nonoutbreak restaurants, through systematic environmental evaluations.

Study Results: For this study, systematic evaluations were conducted in restaurants in which foodborne illness outbreaks had occurred and in restaurants in which outbreaks had not occurred. Results indicated that Norovirus was the most common foodborne disease agent identified, accounting for 42% of all confirmed foodborne outbreaks during the study period. Handling of food by an infected person or carrier (65%) and bare-hand contact with food (35%) were the most commonly identified contributing factors. Outbreak and nonoutbreak restaurants were similar with respect to many characteristics, but did differ in the presence of a certified kitchen manager (CKM); 32% of outbreak restaurants had a CKM, but 71% of nonoutbreak restaurants had a CKM (OR= 0.2; 95% CI=0.1 to 0.5). CKMs were associated with the absence of bare-hand contact with foods as a contributing factor, fewer norovirus outbreaks, and the absence of outbreaks associated with Clostridium perfringens. Food safety certification of kitchen managers appears to be an important outbreak prevention measure.

Publications and Presentations

Food Workers’ Food Preparation Practices Focus Group Study
Objective: To evaluate behavioral factors, barriers, and motivations that influence safe food-handling practices in food-service establishments.

Study Results: In focus groups on food workers’ food safety practices, some food workers reported unsafe food preparation practices, such as inappropriate glove use and not checking the temperatures of cooked, reheated, and cooled foods. Most workers, however, reported safe practices (e.g., washing their hands after preparing raw meat). Workers identified a number of factors that impacted their ability to prepare food safely, including time pressure; structural environments, equipment, and resources; management and coworker emphasis on food safety; worker characteristics; negative consequences for those who do not prepare food safely; food safety education and training; restaurant procedures; and glove and sanitizer use. Results suggest that food safety programs need to address the full range of factors that impact food preparation behaviors.

Publications and Presentations

Food Workers’ Food Preparation Practices Population Study
Objective: To determine self-reported prevalence of food service workers’ safe and unsafe food preparation practices at the population level.

Study Results: In a telephone survey of randomly selected food service workers, respondents commonly reported risky food preparation practices. Respondents said that at work they did not always wear gloves while touching ready-to-eat (RTE) food (60%), did not always wash their hands or change their gloves between handling raw meat and RTE food (23% and 33%), did not use a thermometer to check food temperatures (53%), and had worked while sick with vomiting or diarrhea (5%). Workers responsible for food preparation reported washing their hands and wearing gloves when handling RTE food more often than workers not responsible for food preparation. Workers who cooked reported changing their gloves more often than workers who did not cook. Workers in chain restaurants more frequently reported using thermometers than workers in independently owned restaurants.

Publications and Presentations

Ground Beef Handling Practices Study
Objective: To evaluate ground beef handling practices and the use of irradiated ground beef in restaurants.

Study Results: Interviews and observations in restaurants that handle raw ground beef revealed that risky ground beef handling practices were pervasive in restaurants. Sixty-four percent of restaurants reported they never took the temperature of fresh ground beef upon delivery, and 50% reported they never took the final cook temperature of hamburgers. Observations indicated that in 49% of restaurants, hands were not washed after handling raw ground beef, and in 60% of restaurants, hands were wiped on wiping cloths or aprons after handling raw ground beef. Only 1% of restaurants reported always or sometimes purchasing irradiated ground beef, and 29% reported that they had never heard of irradiated ground beef. These results indicate the need for food worker educational campaigns that focus on hand hygiene, avoiding cross-contamination, and verification of the final cook temperatures of ground beef.

Publications and Presentations

Hand-Hygiene Study
Objective: To describe restaurant food workers' hand hygiene practices and identify factors associated with safe hand hygiene practices.

Study Results: Observations of workers preparing food at work (n = 321) indicated that workers engaged in approximately 8.6 activities per hour for which hand washing is recommended. However, workers made hand washing attempts in only 32% of these activities and washed their hands appropriately in only 27% of these activities. Attempted and appropriate hand washing rates were significantly higher in conjunction with food preparation than other activities (e.g., handling dirty equipment). Attempted and appropriate hand washing rates were significantly lower when gloves were worn than when gloves were not worn. Hand washing and glove use were more likely to occur when workers were not busy. Hand washing was more likely to occur in restaurants that provided food safety training, with more than one hand sink, and with a hand sink in the worker’s sight. Glove use was more likely to occur in chain restaurants and in restaurants with glove supplies in food preparation areas. These findings suggest that food worker hand washing practices need to be improved, glove use may reduce hand washing, and restaurants should consider reorganizing their work activities to reduce the need for hand washing. Findings also indicate that several factors are related to hand hygiene practices and support suggestions that food worker hand hygiene improvement requires multidimensional programs.

Publications and Presentations

Manager Certification and Inspection Scores Study
Objective: To determine if the presence of a certified kitchen manager results in fewer critical violations.

Study Results: Restaurants are associated with a significant number of foodborne illness outbreaks in the United States. Certification of kitchen managers through an accredited training and testing program may help improve food safety practices and thus prevent foodborne illness. In this study, relationships between the results of routine restaurant inspections and the presence of a certified kitchen manager (CKM) were examined. We analyzed data for 4,461 restaurants in Iowa that were inspected during 2005 and 2006 (8,338 total inspections). Using logistic regression analysis, we modeled the outcome variable (0 = no critical violations [CVs]; 1 = one or more CVs) as a function of presence or absence of a CKM and other explanatory variables. We estimated separate models for seven inspection categories. Restaurants with a CKM present during inspection were less likely to have a CV for personnel (P < 0.01), food source or handling (P < 0.01), facility or equipment requirements (P < 0.05), warewashing (P < 0.10), and other operations (P < 0.10). However, restaurants with a CKM present during inspection were equally likely to have a CV for temperature or time control and plumbing, water, or sewage as were restaurants without a CKM present. Analyses by type of violation within the temperature and time control category revealed that restaurants with a CKM present during inspection were less likely to have a CV for hot holding (P < 0.05), but the presence of a CKM did not affect other types of temperature and time control violations. Our analyses suggest that the presence of a CKM is protective for most types of CVs, and we identify areas for improving training of CKMs.

Publications and Presentations

Tomato-Handling Practices Study
Objective: To identify the types of tomatoes used in restaurants, describe tomato-handling practices, and to identify factors associated with safer tomato-handling practices.

Study Results: In recent years, multiple Salmonella outbreaks have been associated with fresh tomatoes. Investigations have indicated that tomato contamination likely occurred early in the farm-to-consumer chain, although tomato consumption occurred mostly in restaurants. Researchers have hypothesized that tomato-handling practices in restaurants may contribute to the occurrence of these outbreaks. However, little empirical data exists on how restaurants handle tomatoes. Thus, this study examined restaurants’ tomato-handling practices. Environmental Health Specialists Network (EHS-Net) members conducted an observation of tomato-handling practices in 449 restaurants. The data indicated that handling tomatoes appropriately posed a challenge to many restaurants. Produce-only cutting boards were not used in 49% of tomato cutting observations and gloves were not worn in 36% of observations. Although tomatoes were washed under running water, as recommended, in most (82%) washing observations, tomatoes were soaked in standing water, a practice not recommended by FDA, and the water-tomato washing temperature differential did not meet FDA guidelines in 21% of washing observations. About half of all batches of cut tomatoes in holding were above 41º F, the temperature recommended by the FDA. Additionally, the maximum holding time for most (73%) cut tomatoes held above 41º F exceeded the FDA recommended holding time of four hours for unrefrigerated tomatoes (i.e., tomatoes held above 41º F). The information provided by this study can be used to inform tomato-associated illness outbreak prevention and intervention efforts.

Publications and Presentations

Projects in Progress

Chicken-Handling Practices Study
Objective: To collect descriptive data on chicken handling and cooking practices in restaurants. Specifically, we will collect data on:

• opportunities for cross contamination from raw chicken to the environment during storage, preparation, and cooking,
• final temperatures of chicken immediately after cooking, and
• opportunities for cross contamination from a contaminated environment to cooked chicken during preparation and cooking.

Cooling Study
Objective: To collect descriptive data on cooling procedures of potentially hazardous foods. We will collect data on

• rapid cooling procedures used,
• begin and end food temperatures during the observation period, and
• types of foods being cooled.

Environmental Surface Sampling Study
Objective: To determine whether outbreaks can be predicted on the basis of environmental samples collected in food-service establishments. This study is being conducted in Iowa.

Food Allergens Study
Objective: To describe restaurant managers’ and workers’ food allergen knowledge, attitudes, policies, and practices.

Foodborne Illness Complaint System Project
Objective: To develop an “ideal” foodborne illness complaint capture form and evaluation questionnaire.

Foodborne Illness Outbreak Study
Objective: To identify contributing factors to foodborne illness outbreaks in food-service facilities and to describe the characteristics, policies and practices of those facilities. Food-service facilities include restaurants, delis, cafeterias, schools, nursing homes, etc.

Study results: Environmental assessments conducted as part of 154 foodborne illness outbreak investigations in food service establishments provided data on a number of establishment characteristics, policies and practices that may serve as potential antecedents to foodborne illness outbreaks. These data are summarized below as preliminary findings.

• The majority (84%) of the foodservice establishments involved in the outbreaks were complex establishments, meaning a complex food handling process is utilized for one or more foods handled in the establishment. Additionally, 13% were cook serve establishments, and 3% were prep serve establishments.
• Spanish was the primary language of 58% of food workers but only 41% of managers could speak Spanish.
• Floor cleaning policies existed in 95% of establishments, but only 37% of these policies were written.
• Fewer establishments had policies on cleaning of food contact surfaces (88%), cutting boards (89%), and food slicers (72%).
• More managers (66%) received paid sick leave than workers (35%).
• The majority (96%) of establishments had hand sinks available in employee restrooms and work areas (94%). However, hands-free operated sinks were rare (restrooms: 4%; work areas: 3%).

Environmental data such as these can inform food safety program action or hypothesis generation regarding antecedents to foodborne illness outbreaks. Systematic collection, analysis, interpretation, and dissemination of environmental data from foodborne disease outbreak investigations can support the overall foodborne disease surveillance system in the United States, strengthening the ability of food-control authorities at all levels of government to formulate food safety action and assess the effectiveness of those actions.

Publications and Presentations

Ill Food Worker Study
Objective: To describe restaurants’ existing ill food worker policies; practices associated with ill food workers, including symptoms that prompt food workers to call in sick and symptoms that prompt managers to send food workers home; and reasons why food workers work while ill.

Kitchen Manager Certification Study
Objective: To examine the relationship between KM/PIC certification, food safety knowledge, and attitudes. The study will describe and compare the food safety knowledge levels and attitudes of certified KM/PIC and non-certified KM/PIC.

Leafy Greens Study
Objective: To collect descriptive data on the storage and preparation policies and practices of leafy greens prepared for raw consumption. We examine

• Leafy green types (e.g., spring mix, iceberg) - form upon receipt (e.g., pre-cut, whole, bagged); type of shipping containers; type of records maintained (e.g., temperature records, source records); and, where possible, the condition and temperature upon receipt.
• Leafy green storage (e.g., type of storage units, temperature of storage units, temperature of product, type of storage containers) in the restaurant.
• Leafy green preparation (e.g., washing, cutting, chopping and mixing practices; buffet serving line practices; temperatures during preparation; form in which greens are served; employee hand contact with leafy greens).

Microwave Use Study
Objective: To determine whether a larger study to assess associations between microwave oven usage in food establishments and foodborne illness. This determination will be made after characterization of

• prevalence of microwave oven usage in different types of food establishments.
• types of foods heated or cooked in microwave ovens at different types of food establishments.
• microwaving protocols, if present, in different types of food establishments.
• types of microwave ovens used in different types of food establishments.

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