食品安全案例分析题

食品安全案例分析题课程习题集1--案例分析题（25个案例）Case studyCase Study 1.1Fourteen people became ill after eating pie that had been highly contaminated with salmonella enteritidis. Several of the victims were hospitalized, and a man in his forties, who was otherwise in good health, died as a result of the foodborne illness.In this outbreak, cream, custard, and meringue pies were made using ingredients form shell eggs. The pies were baked in a restaurant bakery and were stored for 2-1/2 hours in a walk-in cooler before being transported in the trunk of a car to a private company outing. The pies were consumed three to six hours later. Leftover pie was consumed later that evening and the next day after having been kept unrefrigerated for as long as 21 hours.▲What condition m ay have promoted bacterial growth?Case study 2.1Bruce, the morning prep cook at a local restaurant, was preparing shredded cheese to be used on pizza. His procedure included cutting the cheese into small blocks and then shedding the cheese by hand. He prepared several 4-gallon containers and left the containers out at room temperature [70℉(21℃)] until use. Three of the 4 containers were used on pizzas later that day. The next day, the fourth container of cheese was used. On both days, the pizzas were cooked in an oven set to 500℉(260℃).Four days later, several people came back to the restaurant and said that they had become ill a few hours after eating pizza there. Only people who ate pizza on the second day appeared to become ill.1.What foodborne hazard may have been associated with this foodborne illness?2.How could this have been prevented?Case study 2.2In Albuquerque, New Mexico, a well-known food establishment, identified as Restaurant A, had been packing customers in for years. The owners took pride in keeping the establishment spotlessly clean and serving daily thousands of thick juicy steaks and gigantic Idaho potatoes. When some baked potatoes were left at closing time, they were stored on a kitchen counter or shelf overnight. The next morning, the salad chefs would arrive to peel, dice, and mix the leftover potatoes with other ingredients to make the other side order special of the day: potato was containerized and chilled before serving at noon.One day, the potato salad was made and served as usual. Customers came in for lunch and some ate potato salad. The next day, 34 customers were hospitalized for botulism; 2 died. Before this incident, the Food and Drug Administration (FDA) defined Potentially Hazardous Foods (PHF) as any moist, high protein food capable of supporting rapid germ growth. After this deadly incident, the FDA included cooked potatoes in the list of PHF!Just how did those people get botulism from potato salad?Case Study 3.1Michelle is in charge of all the cold salad preparation at a local hotel restaurant. Her main responsibility is to prepare green salads for the evening meal. When she arrived at work oneday,the food manager on duty noticed that she was coughing and sneezing frequently. Michelle also indicated that she was battling a case of the flu.▲How should the food manager handle this situation?Case Study 3.2Cameron just purchased a new food thermometer. He checked to see that it was approved for use in food and it could measure 0°F(-18℃) to 220°F(104℃). He found the sensing area and then calibrated it properly. He was excited by his new purchase and wanted to see how well the thermometer performed. He first measured raw meats in the cold room. They all checked out well and measured between 35°F(2℃) and 41°F(5℃). As he exited the cold room, he immediately went to the customer self-service bar and measured the temperature of the cooked scrambled eggs. They measured 145°F(63℃). Cameron was satisfied measured higher than 135°F(57℃).▲What error did Cameron make when measured food temperatures?Case Study 3.3An outbreak of foodborne Hepatitis A virus occurred in a small Missouri town. One hundred and thirty people became ill and 4 died as a result of their illness. Cases stemming from this outbreak were reported as far away as Oklahoma, Florida, Alabama, and Maine.A foodborne disease investigation revealed that all of the victims had consumed lettuce,either in salad or as a garnish. Investigators ruled out the theory that the lettuce had been contaminated at the source,because other restaurants supplied by the same source experienced no illnesses. In the end, the Missouri Department of Health Officials concluded that direct contamination of food by infected workers was the most likely cause of the outbreak. The initial source of the illness was believed to be a waiter who had been infected by his child in day care. The waiter and 4 other food workers who tested positive for the Hepatitis A virus handled lettuce and were involved in preparing and serving salads.▲What went wrong?Case Study 4.1David Jones is manager of the Great American Cafe. As part of a newly implemented self-inspection program, David performs an inspection of the walk-in refrigerator. During the inspection, David notices that turkeys for tomorrow’s dinner are not covered during thawing, and they are stored directly above several washed heads of lettuce. Other food items are stored on shelves lined with aluminum foil in covered containers that are not labeled or dated. David also notices that boxes of produce have been stacked closely together on the floor of the walk-in cooler, and the thermometer is hanging from the condensing unit.1.What food safety hazards exist in the walk-in refrigeration unit at the Great AmericanCafe?2.Which of these hazards might result in food contaimination and spoilage?3.What should be done to correct the problems that Mr.Jones observed during hisinspection?Case Study 4.2Metro Market is a combination convenience store and delicatessen. Deliveries are received between 9:00 a.m and 3:00 p.m.,Monday through Friday. Store employees are frequently too busy to check the deliveries in and transfer products to approved storage facilities during the noon rush. Therefore, food and non-food items are held in a secured area off the receiving dock until someone is available to process them.1.What food safety hazards exist at Metro Market?2.If you were manager of Metro Market, what would you do to improve receiving andstorage activities?Case Study 4. 3In the mid-1990s, heath departments in Washington, California, Idaho, and Nevada identified nearly 600 people with culture-confirmed Shiga toxin-producing Escherichia coli infections. Many of the victims reported eating at Chain A restaurants during the days preceding onset of symptoms.Of the patients who recalled what they ate in a Chain A restaurant, a large percentage reported eating regular-sized hamburger patties. Chain A issued a multi-state recall of unused hamburger patties. The Shiga toxin-producing Escherichia coli bacteria were isolated from 11 batches of patties from Chain A. These patties had been distributed to restaurants in all states where the illness occurred. Approximately 20% of the patties connected with the outbreak were recovered during a recall.A team of investigators from the Centers for Disease Control and Prevention identified 5 slaughter plants in the United States and 1 in Canada as the likely sources of carcasses used in the contaminated meat. The animals slaughtered in domestic slaughter plants were traced to farms and auctions in 6 western states.No 1 slaughter plant or farm was identified as the source of contamination.Shiga toxin-producing Escherichia coli can be found in the intestines of healthy cattle and can contaminate meat during slaughter. Slaughtering practices can result in contamination of raw meat with these bacteria.In addition, the process of grinding beef can transfer the disease-causing agents from the surface of the meat to the interior. Therefore ground beef can be internally contaminated.1.What would be the likely impact of this outbreak on consumer confidence?2.What was the impact of this outbreak on food safety?Case Study 5.1In the following exercise, a recipe for BBQ ribs is used to demonstrate application of the HACCP system. Use the recipe in FIGURE 5.13 and follow the decision tree in Appendix E to determine why each step is needed to ensure the safety of the finishedPre-preparation1.Thaw spareribs under refrigeration at 41℉(5℃) for 1 day or untilcompletely thawed.2.Wash hands before starting food preparation.bine all of the ingredients for the marinade in a large bowl. Preparation4.Score the ribs with a sharp knife. Place the ribs in the marinade.Marinatethem for at least 4 hours at a product temperature of 41℉(5℃) orlower in refrigerated storage.5.Place the spareribs in a smoker at 425℉(220℃) for 30 minutes.6.Reduce the heat to 375℉(190℃) and continue smoking the ribs to afinal internal temperature of 145℉(63℃) or higher. This phase of thecooking process should take about 50 minutes.Brush the honey on the spareribs during the last 5 minutes of thesmoking process.Figure 5.14 Flow Chart for Spareribs(Adapted from:HACCP Reference Book,1993)Holding/Service7.Slice the ribs between the bones and maintain at 135℉(57℃) or abovewhile serving.Cooling8.Transfer any unused product into clean 2-inch deep pans.Quick-chill theproduct from 135℉(57℃) to 70℉(21℃) within 2 hours and from 135℉(57℃) to 41℉(5℃) within 6 hours.Storage9.Store the chilled product in a covered container that is properly datedand labeled. Refrigerate at 41℉(5℃) or below.Reheating10.Heat spareribs to an internal temperature of 165℉(74℃); or 190℉(88℃)in a microwave oven within 2 hours.Case Study 5.2A Shiga toxin-producing Escherichia coli outbreak at a restaurant in Boise, Idaho, was traced to romaine lettuce used in salad. Thirteen confirmed and 8 probable cases of the illness were reported during the outbreak. While 1 person who was ill required hospitalization, none experienced serious complications from their illness.All of the victims had eaten at the same restaurant and 95% of them had outbreak may have been caused by cross contamination between beef and chicken were ruled out when it was learned that beef products were prepared on one side of the kitchen and chicken on the other. In addition,food workers were responsible for working with either beef or chicken but not both.Romaine lettuce turned out to be the cause of the outbreak.Investigators tracked the lettuce back to its source and determined that contamination had occurred at the restaurant.Sophisticated blood analysis showed that some food workers at the restaurant had been previously infected by Shiga toxin-producing Escherichia coli bacteria for several days.How could this situation have been prevented?Case Study 6.1The O.K. Corral Restaurant is a buffet style operation that offers customers a choice of roast beef, ham, or turkey in addition to several hot vegetables. The meat and poultry on the buffet are placedon wooden cutting boards and are carved in the dining room in front of the customers. The temperature of the meat and poultry is out of the danger zone when it leaves the kitchen. However, no effort is made to make these products hot once they reach the dining room. The carver periodically wipes his carving utensils with a damp kitchen towel.1.What food safety risks exist at the O.K. Corral?2.What steps should the manager take to correct the food safety problems that exist in thefacility?Case Study 6.2Mark Sellmore is th e deli manager at Longfellow’s Supermarket. Mark has been given permission to purchase a new slicer for the department. Mark’s store manager has given him only one instruction. “Buy the most equipment possible for the money you spend.”1.What strategy should Mark use when purchasing the new slicer?2.What factory should Mark use to determine the deli’s need for the slicer?3.What design and construction features should Mark use when he is making comparisonsbetween slicers?4.What standards organizations might Mark consult when evaluating different kinds of slicers?Case Study 6.3A gastrointestinal disease outbreak affected 123 of the 1,200 individuals who attend a meeting at the convention center in Columbus, Ohio. The initial assumption that the outbreak was forborne did not pan out. Although 2 food items were significantly associated with the illness, their connection proved to be coincidental.Based on the incubation period, symptoms, and duration of the illness, investigators speculate that Giardia lamblia and a Norwalk-like virus caused the illness. Because both agents are commonly waterborne, investigators turned their attention to the water supply at the convention center. Of particular interest was an ice machine which supplied the portable bars. It was discovered that a flexible tube from the machine had been inserted into a floor drain. When the machine’s filters were serviced, the tube formed a connection between the ice machine’s water supply and raw sewage.1.What type of plumbing hazard contributed to the foodborne disease outbreak discussed in thecase study?Case study 7.1Ted is night manager of the deli at the Regal Supermaket. One evening Ted noticed that there was a large amount of detergent suds in the third compartment of the manual equipment and utensil washing sink. The deli uses chlorine as a sanitizer. When asked about the soap suds in the sanitizing water, the dish washer indicated this was a common occurrence when there were manythings to wash, especially toward the end of the cleaning and sanitizing process.1.Should Ted be concerned about what he observed? Why?2.What should Ted tell the dish washer to do when there is a large amount of detergent inthe sanitizer?3.What could the dish washer do to prevent detergen from getting into the sanitizer?Case study 7.2On a Sunday mornig the food manager of the Shady Rest long-term care facility noticed that the mechanical dishwasher was not producing water hot enough to properly sanitize equipment and utensils that were being run through the machine. It was not possible to get someone to repair the machine until first thing Monday morning.1.How should the facility wash and sanitize dishes until the dishwasher is fixed?2.Are there other alternatives that might be used in the interim?3.Do you think the food service should be suspended at the facility uuntil the machine isrepaired ? Why or why not ?Case study 7.3A Salmonella outbreak involving 107 confirmed and 51 probable cases occurred in DodgeCounty, Wisconsin. The illness was caused by eating raw ground beef commonly known as steak tartare. Investigators suspect inadequate cleaning of the meat grinder may have been the cause of the problem. Employees of the butcher shop where the ground beef was purchased indicated that the parts of the grinder were cleaned and sanitized at the end of each day.However, the auger housing, which was attached with nuts and bolts, could not be easily removed for cleaning and sanitizing. Employees indicated they had been instructed not to remove the auger housing for cleaning.1. What went wrong?2. How could this outbreak have been prevented?Answers to case studies are provided in Appendix A.Case Study 8.1John Smothers is in charge of remodeling the meat department at Kelly，s Supermarket. The meat department provides a variety of meat, poultry, and fish items and specializes in customized orders. The equipment in facility is not new but still meets current design and construction standards. However, the floors and walls in the department are old and need to be upgraded.1What criteria should John use when considering alternative floor and wall materials for the facility?2Why is wood flooring not recommended for this area?3What color wall materials are recommended? Why?4What features of a meat department should influence the selection of floor and wall materials?Case Study 8.2Ryan，s Hamburgers is small restaurant that specializes in hamburgers and tacos. A prep cook at Ryan，s was recently diagnosed with Hepatitis A virus. As a result, several employees and customers were required to be immunized against the disease. An inspection by the local health department revealed that the handwashing lavatory in the food prep area at Ryan，s was out of service. The only lavatories available to employees on duty were the ones in the restrooms.1Does the handwashing situation at Ryan，s pose a health risk for customers?How?2What action should the local health department take against Ryan，s?3What action should the owner/operator of Ryan，s take to prevent a similar incident in the future?4What are some of the likely effects this episode will have on Ryan，s restaurant? Case Study 8.3Scientists from North Carolina State University have demonstrated how easily cockroaches can spread Salmonella organisms among themselves and to foods. The research, reported in the February 1994 issue of Journal of Food Protection, confirms that cockroaches are capable of acquiring and infecting other cockroaches and objects.Cockroaches are attracted by warmth, darkness, food, and moisture. Given the number of ways cockroaches can become contaminated, by feeding on infected food or feces, contacting an infected cockroach directly or indirectly, or by drinking an infected water source, the risk they pose should be taken seriously. The fact that cockroaches can acquire and infect each other and other objects with salmonella bacteria is an inportant point for the food industry to remember.1What is the best way to control cockroaches in a food establishment?Case Study 9.1It was 1989, a beautiful fall day in San Francisco. The World Series was just getting underway in Candlestick Park; and then, the ground began to shake!Across the city, a banquet was just getting started at the culinary arts school. As the ground shook and buildings swayed, guests, students, and staff evacuated the building as quickly as possible. Meanwhile, in the dining room, a large ornate crystal chandelier was loosened from the ceiling and came crashing down, spraying fragments of glass across the area, including the buffet tables that were loaded with food. When the tremors stopped, the managers in charge of the food service were faced with immediate decisions concerning how to proceed after this catastrophic event. Because it was evening, the keys for supplies kept for emergencies were not available.1.Make a list of the problems faced in this emergency and decide what should be done first,second, and so forth.2.What community resources are needed to cope with this disaster?3.How would you manage the food without electricity and a potable water supply?Case Study 9.2As a new employee was refilling the deep fat fryer, some excess cooking oil spilled onto the floor. Later that morning, the fry cook fell due to the slippery floor. After the fall, the cook was still in severe pain and was unable to return to work.1.Why did this accident happen?2.How can you help the cook?3.How can you prevent future falls like this one?Answers to the case study questions are provided in Appendix A.Case Study 10.1The U-Go market decided to expand its business by opening a delicatessen section to serve fried chicken, potato salad, macaroni salad, and cold cuts of meat. After the equipment arrived, the vendor offered to give employees training on how to safely operate the equipment. At first, the owner refused, s aying, “Training takes time and time is money.” The certified food manager in charge of this area objected, by replying “The products to be sold are all potentially hazardous foods.”1.Why did he say that?2.What would you do in this situation?Case study 11.1A few hours after lunch, a customer returns to a restaurant and complains to a waiter that he got sick after eating the chicken salad. The customer claims that the chichen salad he had eaten for lunch was responsible for his illness.1. How should the waiter handle this customer complaint?Case study 11.2Inspector Jones arrives at Don’s food establishment for the quarterly inspection. Don is really busy and tells Mr. Jones to go ahead. When Mr. Jones returns with the results of the inspection, Jone is surprised. Mr. Jones has noted that the sanitizer dispenser in the chemical dishwasher is broken. 1.What should Don du?Answers to the case studies are provided in the answer key.。