Risks of Practices, Procedures and Processes that Lead to Outbreaks of Foodborne Diseases

Abstract

Factors that contributed to outbreaks of foodborne diseases reported in the U.S. from 1977-1982 are identified and classified by disease and place where implicated foods were mishandled. Data for these years are tabulated and combined with data from the years 1961-1976. Inadequate cooling-either leaving foods at room or warm outside temperatures or storing them in large containers while being refrigerated-was associated with most of the outbreaks. Ranking of all factors has changed little over four periods of review, but during the last period numerous outbreaks primarily due to ingestion of raw clams and raw oysters caused an increase in the factors: contaminated raw foods and obtaining foods from unsafe sources. This has been primarily due to raw clam-, oyster-and milk-associated outbreaks. The three most frequently identified factors that contributed to salmonellosis were improper cooling, contaminated raw products, and inadequate heating; to staphylococcal food poisoning were colonized persons handling cooked foods, lapse of 12 or more hours between preparing and eating, and improper cooling; to botulism were inadequate heat processing, improper fermentations, improper room temperature holding; to C. perfringens enteritis were improper cooling, lapse of 12 or more hours between preparing and eating, and inadequate reheating (followed closely by improper hot holding); to shigellosis were colonized persons handling implicated foods, improper cooling, and lapse of 12 or more hours between preparing and eating; to V. parahaemolyticus gastroen-teritis were contaminated raw ingredients, improper cooling, and cross contamination; to typhoid fever were colonized persons handling implicated foods, lapse of 12 or more hours between preparing and eating, and several time-temperature factors tied for third; to B. cereus gastroenteritis were improper cooling, lapse of 12 or more hours between preparing and eating, and improper hot holding. The principal factors associated with outbreaks stemming from foods prepared in foodservice establishments were improper cooling, lapse of 12 or more hours between preparing and eating, colonized persons handling implicated foods, inadequate reheating and improper hot holding. Important factors that contributed to outbreaks in homes were contaminated raw foods, inadequate cooking, unsafe source, improper cooling, and lapse of 12 or more hours between preparing and eating. Major contributing factors associated with operations in food processing plants were inadequate heat processing, contaminated raw ingredient, improper cooling, colonized persons handling implicated foods, improper cleaning of equipment, and improper fermentation. Those factors cited above for each category are the vital few items to stress in food safety programs. The many other items that are a part of food protection programs are of lesser importance or trivial. Accompanying the development of epidemiology and improved surveillance of foodborne diseases, specific factors (faulty practices, procedures and processes) that contributed to the occurrence of outbreaks of these diseases have become apparent. Reviews of such contributory factors have been published for outbreaks that were reported in the United States (4-7,9), England and Wales (31), Canada (43), and New South Wales, Australia (20). Factors that contribute to outbreaks of foodborne illness reflect hazards. Hence, they aid in establishing critical control points which are operations where measures that will either eliminate or reduce hazards can be exercised. Of further importance, they provide guidance for assessing the probability of occurrence of a hazard (risk) (12,45). They also indicate where verification of the monitoring of critical control points is needed. These contributory factors should set priorities for legislators, program administrators, supervisors and inspectors to use when considering matters related to food safety. Emphasis must be placed on real and proven contemporary problems. This review updates information about factors (hazard-ous operations) that contributed to outbreaks of foodborne diseases in the United States and assesses the risk of each factor. MATERIALS AND METHODS The present study followed methods that were used in the past (4-6), which consisted of gathering information on factors that contributed to outbreaks of foodborne disease from reports submitted to the Centers for Disease Control (CDC) from health agencies, investigations made by CDC personnel or articles published in public health, medical or food science journals. Morbidity and Mortality Weekly Reports (19) and botulism surveillance data (1977-1982) were reviewed to get confirmation and further information.