Food-Borne Illness Related to the Increased Incidence of Salmonella Enteritidis
PDF Version of BQA 98-014
(PDF, 22 KB)
Date: July 13, 1998 -- DSL-BQA-98-014
To: Nursing Homes NH
Facilities for the Developmentally
Disabled FDD - 05,
Hospitals HOSP - 05,
Community Based Residential
Facilities CBRF - 04,
Adult Family Homes AFH
Adult Day Care Centers ADC 03
From: Judy Fryback, Director, Bureau of Quality Assurance
The Wisconsin Bureau of Public Health informed the Bureau of Quality Assurance of a
substantial increase in the number of persons in Wisconsin who had diarrheal illnesses
during 1997 due to the bacterium Salmonella Enteritidis compared to the previous
three years. During 1997, there were 395 reported cases of laboratory-confirmed Salmonella
Enteritidis infections. This was roughly two and a half times the average annual
number of cases during the previous three years. There was an even greater increase in the
occurrence of Salmonella Enteritidis among elderly persons; the age-specific
incidence rate for persons 65 and older during 1997 was 9.1 cases per 100,000 population,
which represents a three-fold increase from the average of 2.9 cases per 100,000
population per year during the years 1994-96. In addition, there were eight outbreaks with
a common exposure such as a restaurant or party. One of these outbreaks occurred in a
nursing home and resulted in ten residents having a diarrheal illness due to Salmonella
Enteritidis with one of the residents being hospitalized.
Epidemiologic investigations of the sporadic and outbreak-associated cases suggested
that contaminated eggs were primarily responsible for the increase in reported infections.
Eggs have been linked to infections due to Salmonella Enteritidis in other parts of
the country as well. The Wisconsin Department of Agriculture, Trade and Consumer
Protection conducted a trace-back of eggs that were associated with two outbreaks and
identified chicken flocks living in environments contaminated with Salmonella
Enteritidis. Eggs from these flocks are no longer being sold as shell eggs in the
retail market. However, the source of eggs could not be identified for all cases of Salmonella
Enteritidis infection which occurred during 1997, because the small size of some
clusters and the sporadic cases did not allow identification of a particular source of
eggs even though there was evidence that the infections were due to eggs. Therefore, it
cannot be assumed that all Wisconsin flocks with Salmonella Enteritidis contamination
have been identified.
Food borne illness is a serious health issue for all persons, but persons who are
elderly, have weakened immune systems, or suffer from chronic disease such as diabetes are
at a higher risk of severe illness due to Salmonella Enteritidis. In fact, during
the years 1985-1991, the case-fatality rate in hospital- and nursing home-associated
outbreaks was 3.0%, 70 times the case-fatality rate in other settings (0.043%). The
symptoms of Salmonella Enteritidis include diarrhea, fever, nausea, vomiting,
abdominal pain, and headaches. These symptoms can vary in both severity and onset.
Food service operations in health care and community settings must guard against
outbreaks of food borne illness. The federal Centers for Disease Control and Prevention
and the state Bureau of Public Health recommend the following measures to protect
residents, clients and patients living in health care and community settings:
Under no circumstances should raw eggs be served.
In institutions with high risk populations, pasteurized egg products should be
substituted for raw eggs used in recipes, where possible.
Separate blenders should be used for pureeing other foods if a blender is use for
scrambling eggs. Several outbreaks have been traced to pureed food prepared in the same
blender used to scramble eggs.
Particular attention needs to be given to washing and sanitizing any kitchen equipment
that comes in contact with the contents of shell eggs.
If shell eggs are used in health care and community settings, the Bureau of Quality
Assurance and the Bureau of Public Health are advising health care and community-based
providers to evaluate their food safety practices, including how eggs are purchased and
used in their facilities. In particular, we recommend the following:
Eggs and egg-containing foods must be refrigerated at temperatures of 40º F or below or
kept hot at 140ºF or hotter.
Never accept room temperature, cracked, or broken raw shell eggs.
Thoroughly cook all eggs so that the yolk and white are solid.
Do not accept or use eggs that have passed their "expiration," "sell
by" or "use by date."
Review procedures to prevent cross-contamination between raw eggs or foods containing
raw eggs; including with hands, surfaces, utensils and other foods. For example, hands
should be thoroughly washed with warm, soapy water and dried with single service
disposable towels before and after egg handling. Utensils, equipment, and work areas
should be washed and sanitized before and after coming in contact with raw eggs.
Eggs are not the only source of Salmonella Enteritidis. Other foods
implicated in Salmonella Enteritidis outbreaks include meats and meat products,
poultry, and combination foods, (e.g., salads) that contain the previously mentioned food
products. Food handlers and others who are infected with the bacterium can also spread Salmonella
Enteritidis. Food service employees with a diarrheal illness should be evaluated
medically and should not work while they are symptomatic. If there are questions about
specific cases of diarrheal illness, contact your local health department.
Mishandling and improper cooking and storage of foods are the most common contributing
factors to food borne outbreaks of Salmonella Enteritidis and other food borne
illnesses. Food service employees and others need to be educated about effective
food safety, including purchasing, storing and handling foods properly, cooking foods to
proper temperatures, using effective hand washing practices, keeping food contact surfaces
clean and sanitized, and preventing cross-contamination.
Attached is a memorandum
from the federal Centers for Disease Control and Prevention that answers questions about Salmonella
Enteritidis and eggs (exit DHFS). If you have any questions, please call Billie March, Dietary
Services Consultant, Bureau of Quality Assurance [call
Jean Kollasch at (608) 267-0466] or John Archer,
Epidemiologist, Bureau of Public Health at (608) 267-9009.
PDF: The free Acrobat Reader®
software is needed to view and print portable document format (PDF) files.