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Bureau of Epidemiology | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Bureau of Epidemiology | February 2000 | Utah Department of Health | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| An
Action Plan to Eliminate Salmonella enteritidis Illness
Due to Eggs
The
President’s Council on Food Safety has identified egg safety as one component of food
safety that warrants immediate federal interagency action. The “Egg Safety From
Production to Consumption: An Action Plan to Eliminate Salmonella enteritidis
Illnesses Due to Eggs” was introduced in December 1999. The plan identified the
systems and practices to be implemented to reduce and ultimately, eliminate eggs as a
source of human S. enteritidis (SE) illnesses. An interim goal of the Egg Safety
Action Plan is a 50 percent reduction in egg-associated SE illnesses by 2005.
In support of this plan, Health and Human Services Secretary, Donna E. Shalala, stated, “This ambitious plan is a bold step that will dramatically improve the safety of eggs. Working with the state, industry and consumers, we can achieve our public health goal to eventually eliminate Salmonella illness from eggs”. In addition, Agriculture Secretary, Dan Glickman, said this Administration has made food safety a national priority and has requested substantial funding increases each year for crucial investments in improving food safety, including a nationwide early warning system for foodborne illness, increased inspections and expanded research and consumer education. Americans consume an average of 234 eggs per person per year. Although only an estimated 1 in 20,000 eggs in the U.S. contain SE bacteria, this rate of contamination means that nearly 3.36 million eggs are infected annually, which exposes a large number of people to SE. Because eggs can become contaminated internally from the hen, common egg-handling practices designed to prevent contamination once the shell is broken are now considered to be inadequate. CDC surveillance data show that the rate of isolation of SE from infected humans increased throughout the U.S. during 1976-1994 from 0.5 to 3.9 per 100,000 population. Evaluation of regional trends shows a decrease in the SE isolation rate in the Northeast, where egg quality assurance efforts are the most intensive. In contrast, the rate increased approximately threefold in the Pacific region.A typical case of salmonellosis is characterized by diarrhea, abdominal cramps, nausea, vomiting, fever, and headache. Symptoms usually begin within 6 to 72 hours after consuming food, last 4 to 7 days, and resolve without antibiotic treatment. The benefits associated with preventing human salmonellosis are: (1) the economic benefits of reducing loss of productivity associated with human illness, (2) reduced pain and suffering, and (3) reduced expenditures on medical treatment. The costs associated with human salmonellosis due to SE are estimated to range from $150 million to $870 million annually. Under the new plan, egg producers and processors will implement one of two strategies to improve egg safety:
Strategy II requires implementation of new technologies to kill the potentially dangerous organism, such as in shell pasteurization, at the packer stage of production. Both strategies should improve the safety of shell eggs and processed egg products. The plan also provides a strategy to consolidate egg safety oversight. The Department of Health and Human Services’ Food and Drug Administration (FDA) and the Department of Agriculture’s Food Safety and Inspection Service (FSIS) share federal regulatory responsibility for egg safety. The SE risk assessment model for shell eggs and egg products, developed jointly by the FSIS and the FDA in 1998, predicted that using multiple interventions could achieve a more substantial reduction in SE illnesses than using any one intervention alone. This finding suggests that a broadly based policy is likely to be more effective in eliminating egg-associated SE illnesses than a policy directed solely at one stage of the egg production-to-consumption continuum. At each stage of the egg production-to-consumption continuum, the plan identified the systems and activities necessary to achieve food safety public health goals. The plan offers industry the flexibility to choose from the two SE reduction strategies, each delivering eggs into distribution and to the consumer at an equivalent level of safety. The strategy selection by egg producers and packer/processors determines the point at which the pathogen reduction steps are taken.For the distribution and retail stages, the plan specified the safe handling practices necessary to ensure consumers receive a safe food product. The plan also describes the surveillance, research, and education activities that must also be conducted to achieve the elimination of egg-associated SE illnesses. To consolidate egg safety oversight responsibilities and provide clarity, the President’s Council on Food Safety identified one responsible agency for each stage of the farm-to-table continuum, based on the strengths of each agency. These follow: The performance measures that will be used to assess the progress of the plan are the numbers of SE cases, isolates, and outbreaks annually. The data will be collected using the following existing systems: (1) Foodborne Diseases Active Surveillance Network (FoodNet), (2) National Salmonella Surveillance System (via PHLIS), and (3) National SE Outbreak Surveillance System and Foodborne Diseases Outbreak Surveillance System. The egg safety action plan is available on the web at www.foodsafety.gov/ under “President’s Council on Food Safety”. Salmonella enteritidis in Utah, 1999 The incidence of Salmonella in Utah has increased each year, with the exception of 1997. The lull in 1997 followed a large Salmonella enteritidis (SE) outbreak that occurred in 1996. In addition, in four of the last five years, S. enteritidis has accounted for almost 50% of the Salmonella cases reported in Utah (Table 1).
The number of sporadic cases of SE is continuing to increase in Utah, but single-point outbreaks are primarily responsible for the alarming rates of disease now seen. Salmonella outbreaks are usually traced to foods such as processed meat products, inadequately cooked poultry and poultry products, uncooked or lightly cooked foods containing eggs and egg products, raw milk and dairy products, and foods contaminated with feces by an infected food handler. Epidemics may also be traced to foods that have been processed or prepared with previously contaminated utensils, or on work surfaces contaminated in previous use. SE contamination of chickens and eggs has resulted in many human infections. The consumption of these contaminated products is responsible for the majority of cases of SE in the U.S. Inadequate temperature of food during preparation and cross-contamination during food handling are the most important risk factors resulting in infection. In 1999, 121 of the 374 (32%) cases of Salmonella enteritidis were associated with single-point outbreaks. Of those 121 cases, 64 were involved with an outbreak in June in which homemade ice cream made with raw eggs was served at a company party. Forty-three cases were related to an outbreak in December in an elementary school setting. An additional eight cases were associated with small parties where homemade ice cream was served. Five others were associated with an outbreak where undercooked eggs were served in a jail setting, and one case in a Utah resident was associated with an outbreak in a California college. The significant increases in June and December are the result of single-point outbreaks (Figure 1).
A limitation of our risk assessment is that it is difficult for people to remember what they ate prior to their onset of symptoms. Many patients listed restaurants and grocery stores where they had purchased food. There did not appear to be any patterns where cases were linked to particular stores or eating establishments. Many people had contact with pets but most listed low risk animals such as cats and dogs. Raw or undercooked eggs, poultry and meat appear to be the most common risk factors for SE in Utah in 1999 (Table 3).
Rapid identification and follow-up investigation of cases would help to reduce the number of cases. In addition, prompt environmental investigation of implicated commercial food establishments is necessary. There should be no delay in obtaining environmental and food samples in the event they are needed to complement the patient cultures. The following recommendations should be followed for all commercial food preparation to prevent infection with Salmonella enteritidis. To prevent infection with SE at home, consumers should follow these rules:
Utah Department of Health, Bureau of Epidemiology Monthly Morbidity Summary - February 2000 - Provisional Data
Send comments to: The Bureau of Epidemiology, Box 142104, Salt Lake City, UT 84114-2104 or call (801) 538-6191 Approval 8000008: Appropriation 3705 Rod Betit, Executive Director, Utah Department of Health |
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