Introduction

The foodservice industry boasted more than $300 billion in sales per year and has almost 10 million employees. The typical consumer over age eight had more than four meals per week away from home in 1996. Accordingly, it is not surprising that a significant proportion of foodborne illness arises from contaminated foods obtained from foodservice establishments. Take-out foods can be particularly hazardous because consumers often are not aware of how perishable these foods are and do not take appropriate precautions. For example, many do not realize that if foods are not intended to be eaten within two hours, they should be refrigerated right away and reheated later (1).

The Centers for Disease Control and Prevention (CDC) reported that in the United States each year 76 million people get sick, more than 300,000 are hospitalized, and 5,000 Americans die as a result of foodborne illnesses. These are primarily the very young, the elderly, and the immunocompromised. (2) The CDC also reported that 79% of foodborne illness outbreaks between 1987 and 1992 were due to bacterial contamination. Such contamination is most often due to improper holding temperatures and poor personal hygiene practices. Congressional experts believe the risk of foodborne illness is increasing. (1)

As reported by the CDC, in 2004, a total of 15,806 laboratory-diagnosed cases of infections in FoodNet surveillance areas were identified. Overall incidence per 100,000 persons was 14.7 for Salmonella, 12.9 for Campylobacter, 5.1 for Shigella, and 0.9 for STEC O157. The overall incidence per 1 million persons was 13.2 for Cryptosporidium, 3.9 for Yersinia, 2.8 for Vibrio, 2.7 for Listeria, and 0.3 for Cyclospora. The FoodNet surveillance population is 44.1 million persons (15.2% of the U.S. population) in 10 sites. (3)

Those at greater risk include those who eat meals outside the home more often because their foods are handled by more people. In addition, the very young, the very old, and those with suppressed immune systems due to illness, chemotherapy, or AIDS/HIV are at higher risk of succumbing to contamination. The degree of illness also depends on the amount of pathogen or toxin ingested.

Commercial foodservice establishments, in particular, have a duty to strictly abide by food safety regulations in order to keep the public safe. It is also prudent for eating establishments to carefully abide by safety standards for business reasons. Although an establishment can show that it is taking measures to prevent foodborne illness, the establishment may be at risk for heavy fines or even closure if major violations are found or if employees were not following all possible food safety guidelines. According to the county of Nevada Community Service Agency, a foodservice establishment that developed its own written standards to ensure food safety and that follows proper documented procedures to prevent foodborne illness can use the reasonable care defense if it is sued for an alleged food poisoning outbreak. (4)

Several organizations are involved in promoting food safety. For example, FoodNet provides surveillance of foodborne, parasitic, and viral infections. The Food and Drug Administration (FDA) regulates low-acid canned foods, imported foods, pasteurized milk, many seafoods, rabbit meat, and food for airplane and train rides. (5) The FDA imposes standards on state and local agencies. The FDA?s Food Code is updated every two years and includes proper temperatures for cooking, cooling, refrigeration, reheating, and holding. (1) The Department of Agriculture regulates meat and poultry, pasteurized eggs, and investigates animal and plant diseases. The Department of Agriculture regulates grading of shell eggs but since 1995, the FDA has been responsible for their microbiological safety. Preventing foodborne illness needs to be considered from field, farm, and fishing area to preparation to the table. Hazard Analysis and Critical Control Points (HACCP) should be employed in any quantity foodservice situation. (5)

The Food Marketing Institute has a food protection certification program to teach supermarket employees about the FDA Food Code, food handling, and good hygiene. The National Restaurant Association offers ServSafe, which teaches food handlers about safe food handling practices. (1)

How to Prevent Contamination

Bacteria can be spread from contaminated faucets, paper towel dispensers, and door handles. After using the restroom, use a paper towel to touch the faucet and to open the door. Hands should be washed again in the kitchen?s handwashing sink prior to resuming food preparation. Hands touch many surfaces including light switches, telephones, doorknobs, etc. Employees should wash their hands after touching human body parts other than clean hands, after using the rest room, after handling service animals or aquatic animals, after coughing, sneezing, using a handkerchief or disposable tissue, after using tobacco, eating, or drinking, after handling soiled equipment or utensils, during food preparation when changing tasks, when switching between working with raw and ready-to-eat foods, before putting on gloves for working with food, and after engaging in other activities that contaminate the hands. According to the 2001 Food Code, employees shall clean their hands and exposed portions of their arms for at least 20 seconds. "Food employees shall use the following cleaning procedure:

1. Vigorous friction on the surfaces of the lathered fingers, finger tips, areas between the fingers, hands and arms (or by vigorously rubbing the surrogate prosthetic devices for hands or arms) for at least 10 to 15 seconds, followed by;

2. Thorough rinsing under clean, running warm water; and

3. Immediately follow the cleaning procedure with thorough drying of cleaned hands and arms (or surrogate prosthetic devices)?" Employees should pay careful attention to the areas underneath the fingernails. (6)

Potentially hazardous foods (PHFs) are items that tend to support the rapid growth of bacteria. Accordingly, safety guidelines for handling and storing PHF items must be particularly adhered to. PHFs include protein-containing foods such as milk, dairy products, shell eggs, pasteurized eggs, meats, poultry, fish, shellfish, tofu and soy-protein products. Also cooked potatoes, cooked or partially cooked plant foods, sliced melons, and raw seed sprouts are also considered to be PHFs.

It is important to wash hands and work surfaces often since bacteria, viruses, and parasites can be spread via cutting boards, utensils, and countertops. Cross-contamination occurs when bacteria, viruses, or parasites are spread from one food to another. It is especially important to keep juices from raw meat, poultry, seafood, and eggs, away from ready-to-eat foods. To ensure that foods are heated to proper temperatures, use a clean thermometer to measure the internal temperature of cooked food to make they are cooked to proper temperature. Eggs should be cooked until the yolk and white are firm. If recipes require raw or partially cooked eggs, use pasteurized eggs. Cook fish should until it is opaque and flakes easily with a fork. Refrigerate foods promptly to prevent bacterial growth.

The HACCP (Hazard Analysis and Critical Control Point) system should be used as a systematic approach to in identify, evaluate and control food safety hazards, including biological, chemical or physical agents that have the potential to cause illness or injury. Practices to ensure that hazards are eliminated or minimized include temperature tracking of refrigerators, freezers, hot foods, steam table items, and salad bar items, making sure sanitizer concentrations are adequate to kill germs, and making sure that equipment is in good repair. Critical control points (CCPs) are those points in the process that must be controlled to ensure food safety. A HACCP plan should be developed for each facility. The details of HACCP are outside the scope of this module and therefore will not be discussed.

Common Foodborne Bacteria and Toxins

Most of the time, potential causes of foodborne illness are not readily identifiable. For example, chickens carrying ovarian Salmonella infections, calves carrying E. coli O157:H7, and oysters carrying Norwalk virus or V. vulnificus appear outwardly healthy. Since food animals may contract such organisms from contaminated food and water, we must monitor how these animals are raised as well as what happens during food preparation.

Contamination can occur at any point during the production process. Foods with little salt, sugar, acidity, or preservatives are more likely to be contaminated. (5)

Numerous organisms can cause foodborne illness if allowed to grow and/or produce toxins in foods. Without adequate countermeasures, these organisms can produce dangerous quantities of toxins, or accumulate to dangerous levels. Some of these foodborne bacteria are mentioned below.

One factor that can affect bacterial growth is pH. Acidity, measured by pH, is based on the concentration of hydrogen ions. The lower the pH, the more acidic and sour the food is, and the more difficult it is for bacteria to grow in it. The pH scale ranges from 0 (highly acidic) to 14 (highly basic or alkaline) with the midpoint, 7, as neutral. Foods with acidic pHs below 4.6 such as oranges and tomatoes generally don?t support bacterial growth well. Most bacteria prefer a range of pH 4.6 to 9.0.

Figure 1 pH of Some Common Foods