[Federal Register Volume 64, Number 88 (Friday, May 7, 1999)]
[Notices]
[Pages 24661-24663]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-11319]
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DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration
[Docket No. 99N-1076]
Risk Assessment of the Public Health Impact of Foodborne Listeria
Monocytogenes; Request for Comments and for Scientific Data and
Information
AGENCY: Food and Drug Administration, HHS.
ACTION: Notice; request for comments and for scientific data and
information.
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SUMMARY: The Food and Drug Administration (FDA), in consultation with
the U.S. Department of Agriculture's Food Safety and Inspection Service
(USDA/FSIS), is announcing plans to conduct a risk assessment (RA) to
determine the prevalence and extent of exposure of consumers to
foodborne Listeria monocytogenes and to assess the resulting public
health impact of such exposure. The agencies request comments on
certain aspects of their approach to the RA and request that scientific
data and information relevant to the conduct of the RA be submitted.
DATES: Written comments and scientific data and information by July 6,
1999.
ADDRESSES: Submit written comments and scientific data and information
to the Dockets Management Branch (HFA-305), Food and Drug
Administration, 5630 Fishers Lane, rm. 1061, Rockville, MD 20852.
FOR FURTHER INFORMATION CONTACT: Richard C. Whiting, Center for Food
Safety and Applied Nutrition (HFS-300), Food and Drug Administration,
rm. 3822, 200 C St. SW., Washington, DC 20204, 202-260-0511, FAX 202-
260-9653, or e-mail ``[email protected]''.
SUPPLEMENTARY INFORMATION:
I. Background
L. monocytogenes is a bacterium that occurs widely in both the
agricultural (soil, plants, and water) and food processing environment.
The bacterium is resistant to various environmental conditions such as
high salt or acidity (Ref. 1). L. monocytogenes grows at low oxygen
conditions and refrigeration temperatures, and survives for long
periods of time in the environment, on foods, in processing plants, and
in household refrigerators. Although frequently present in raw foods of
both plant and animal origin, it also can be present in cooked foods
due to post-processing contamination. L. monocytogenes has been
isolated in such foods as: Raw and pasteurized fluid milk, cheeses
(particularly soft-ripened varieties), ice cream, raw vegetables,
fermented raw meat sausages, raw and cooked poultry, raw meats (all
types), and raw and smoked fish (Refs. 1, 2, and 3). Even when L.
monocytogenes is initially present at a low level in a contaminated
food, the organism can multiply during storage, including storage at
refrigeration temperatures. A survey of a wide variety of foods from
the refrigerators of listeriosis patients in the United States found 11
percent of the samples contained L. monocytogenes (Ref. 4).
It is well established that ingestion of L. monocytogenes can
cause serious human illness, listeriosis (Refs. 1, 2, 5, 6, and 7). In
1997, the Centers for Disease Control and Prevention (CDC) Foodborne
Diseases Active Surveillance Network (FoodNet) showed that of all
foodborne illnesses, the rate of hospitalization was highest for
persons infected with L. monocytogenes (88 percent). Similarly, of all
of the foodborne pathogens tracked by CDC, L. monocytogenes had the
highest case fatality rate in that 20 percent of persons infected died.
CDC also found that the incidence of listeriosis is 0.5 per 100,000
population, compared to a combined rate of 51.2 per 100,000 for all 9
of the foodborne illnesses surveyed (Ref. 8). Thus, although serious,
listeriosis is a relatively rare foodborne illness. Most cases of
listeriosis occur in pregnant women or individuals with a predisposing
disease (such as alcoholism, diabetes, or cirrhosis of the liver) or an
impaired immune system resulting from either a disease (such as AIDS)
or immunosuppressive treatment for a malignancy or an organ transplant.
(Refs. 1 and 6).
Listeriosis has a long incubation time (up to 5 weeks) and a range
of symptoms. Infection of a pregnant woman may result in flu-like
symptoms with fever, muscular pain, or headache, or the listeriosis
infection may be asymptomatic. Importantly, however, when a pregnant
woman contracts listeriosis, the fetus or newborn infant is likely to
suffer severe consequences from the maternal infection, including:
Spontaneous abortion, fetal death, stillbirth, neonatal septicemia, or
meningitis. In nonpregnant adults, septicemia and meningitis are the
most common result of a listeriosis infection, although organ
infections and mild gastroenteritis can also occur.
Although the consequences of listeriosis may be severe, an
estimated 2 to 6 percent of the healthy population harbors L.
monocytogenes in their intestinal tract without signs of illness (Refs.
1 and 6). Because the documented prevalence of L. monocytogenes in
people and in commonly eaten foods is much higher than the documented
incidence of listeriosis, some experts believe that the ingestion of
low levels of L. monocytogenes may not result in illness and thus, may
not constitute a general public health hazard (Refs. 9 and 10).
Since 1990, CDC has documented a decrease in the incidence of
listeriosis. Although not certain, this decrease may be attributed to
government and industry programs directed at improved sanitation and
process control. Listeriosis is typically characterized by sporadic
cases. However, a recent multi-State listeriosis outbreak associated
with the consumption of processed meats, with at least 73 illnesses and
16 deaths, has reaffirmed concerns that more preventative efforts are
needed.
Historically, FDA has had a policy of ``zero tolerance'' for L.
monocytogenes based on the absence of the microorganism in a 25-gram
sample of a given production lot. In other words, FDA's position has
been that the detection of any L. monocytogene in a 25-gram sample
renders the food adulterated within the meaning of the Federal Food,
Drug, and Cosmetic Act (21 U.S.C. 342(a)(1)). As recently as 1995, FDA
affirmed this policy, as reflected in the decision in United States v.
Union Cheese Co., 902 F. Supp. 778, 784, 786 (N.D. Ohio 1995). In that
litigation, FDA's expert witness testified that the L. monocytogenes
bacterium grows at refrigerator temperatures and that the level of L.
monocytogenes required to cause illness is unknown (902 F. Supp at
784). FSIS (which regulates meat and poultry) likewise has historically
had a zero tolerance policy for L. monocytogenes.
Other countries, including certain major trading partners of the
United States, take a slightly different approach to L. monocytogenes
contamination. Relying upon their interpretation of the existing
scientific data, countries such as Canada and Denmark have a ``non-zero
tolerance'' for L. monocytogenes for some classes of foods (Refs. 10
and 11).
[[Page 24662]]
For example, in Canada, ready-to-eat foods that have not been
associated with an outbreak and do not allow any growth of L.
monocytogenes during a 10-day period of refrigerated storage may
contain up to 100 L. monocytogenes organisms per gram without being
considered unlawful (Ref. 12). Denmark has six classes of foods that
have to meet various criteria for L. monocytogenes. In raw, ready to
eat foods, for example, 2 of 5 samples can contain between 10 and 100
organisms per gram, and no sample can exceed 100 organisms per gram.
Although the course taken by other countries concerning L.
monocytogenes contamination is not determinative of the U.S. approach,
the policies of certain major trading partners provides further context
to any reexamination of current U.S. policy.
Quantitative RA has recently been identified as a useful tool for
evaluating the public health impact of microbial contamination. USDA/
FSIS and FDA recently completed a quantitative RA of Salmonella
Enteritidis in shell eggs and egg products (Ref. 13). This RA is being
used to review and evaluate Federal regulatory approaches to ensuring
the safety of these products.
As noted, although the incidence of listeriosis is relatively low,
the consequences of such infection are quite serious. A quantitative RA
of the prevalence and extent of exposure of L. monocytogenes will
provide a structured approach to synthesize and evaluate the available
data and information. To the extent that U.S. policy regarding L.
monocytogenes contamination requires reexamination, such a RA can serve
as a foundation for such reconsideration.
II. Objectives of the Risk Assessment
As noted previously, FDA and USDA/FSIS are jointly planning to
conduct an assessment of the risk posed by L. monocytogenes to American
consumers. A RA is a systematic and comprehensive collection of
information and analysis of such information that promotes an
understanding of the interactions of various factors in a complex
situation and provides a basis for making decisions. The goal of this
RA is to provide FDA and FSIS with the information needed to review
current programs relating to the regulation of L. monocytogenes
contamination in foods to ensure that such programs provide maximum
public health protection.
III. Risk Assessment Plan
The RA will seek and analyze three types of information:
Information concerning the epidemiology of foodborne listeriosis,
information concerning the level of L. monocytogenes contamination of
foods and consumption levels of such foods (i.e., an exposure
assessment), and information regarding the human health consequences of
such exposure (i.e., a dose-response analysis).
1. The RA will analyze epidemiological evidence concerning the
foods implicated both in documented outbreaks and in sporadic cases of
listeriosis, the numbers of L. monocytogenes consumed, the populations
which became ill, and the severity of their illnesses.
2. The exposure assessment component of the RA will determine the
frequency of occurrence of L. monocytogenes in different classes of
foods, particularly the ready-to-eat foods that are intended for
consumption without additional heating. Ready-to-eat foods are
represented by numerous types of dairy, seafood, meat, and plant
products. The RA also will collect and analyze information on the
number of viable organisms associated with these foods at the time of
consumption. When data are collected at processing stages prior to
consumption, the RA will utilize models for growth, survival, or
thermal inactivation to estimate actual exposure of the consumer to L.
monocytogenes. The RA also will utilize food consumption databases to
assess the amount of these foods that are consumed. The RA will use the
information about the frequency of occurrence and numbers of L.
monocytogenes and food consumption to estimate the number of L.
monocytogenes cells consumed.
3. The RA will include an evaluation of the dose-response
relationship, which will describe the health effects from consuming
specific numbers of L. monocytogenes organisms. The information that
will form the basis of the dose-response relationship element of the RA
may come from epidemiological, animal, or in vitro studies. FDA and
FSIS recognize that the frequency and severity of illness may be
affected by the food matrix, characteristics of specific strains of the
organism, and variability in human susceptibility.
The RA will examine a number of issues, including: What foods
contribute most to the consumption of L. monocytogenes, what are the
numbers of organisms when a food is contaminated, how frequently are
foods heavily contaminated, are some strains of L. monocytogenes more
virulent that others, what is the extent of organism growth during
storage (including storage at refrigeration temperatures), and what is
the likelihood of illness to various subpopulations from consuming
different numbers of L. monocytogenes. All assumptions and
uncertainties in the RA will be identified and documented. The RA
process will also include an evaluation of the adequacy of current
scientific knowledge, data, and information. This will suggest where
future research could be directed to reduce any uncertainty in the risk
estimate that prevents a clear understanding of the causes and impact
of listeriosis.
IV. Data and Information Requested
FDA and FSIS request comments on the risk assessment approach
outlined previously and the submission of any information relevant to
this RA. The agencies specifically request scientifically valid data on
the quantitative levels of L. monocytogenes in foods and data relating
to rate of consumption of foods likely to contain high levels of L.
monocytogenes.
FDA believes that the credibility and validity of the RA require
that the process for the conduct of the RA be transparent, and thus,
all the data and information evaluated in the context of the RA and
utilized in the RA must be publically available. Accordingly, any data
or information submitted in response to this notice should be in a form
that permits public disclosure. Submitters of data and information
should not mark any information as ``Confidential'' and should fully
expect that any data or information submitted will be made available to
the public. Questions regarding the public availability of data and
information submitted in response to this notice should be directed to
the contact person above.
As noted, the purpose of this request for data is to gather
relevant information to facilitate a valid RA of L. monocytogenes with
the larger goal of providing a sound scientific basis for the agencies'
policies regarding the regulation of L. monocytogenes contamination in
food. Although FDA would seek to remove from the market any existing
food product known to be adulterated, FDA does not intend to utilize
the submitted data and information to support future enforcement
activity against the manufacturers submitting the data. Accordingly, it
is acceptable that data submitted in response to this notice be
``blinded'' in the sense that the data need not identify the particular
manufacturer or processor that was the source of the samples underlying
the results.
[[Page 24663]]
The RA team plans to present a summary of available literature to
the National Advisory Committee on Microbiological Criteria for Foods
at a meeting scheduled for May 26 through 28, 1999, in Chicago, IL. A
copy of the literature summary will be available prior to that meeting
on the Internet at ``http://vm.cfsan.fda.gov''. Comments and data
submitted in response to this notice or at that meeting will be
incorporated into the RA process, and the completed RA will be
publically presented in September 1999.
Two copies of comments and scientific data and information are to
be submitted, except that individuals may submit one copy. Comments and
scientific data and information should be addressed to the Dockets
Management Branch (address above) and identified with the docket number
found in brackets in the heading of this document. Received materials
may be seen in the Dockets Management Branch between 9 a.m. and 4 p.m.,
Monday through Friday.
V. References
The following references have been placed on display in the Dockets
Management Branch (address above) and may be seen by interested persons
between 9 a.m. and 4 p.m., Monday through Friday.
1. Ryser, E. T. and E. H. Marth, Listeria, listeriosis, and food
safety, Dekker, NY, 1991.
2. Farber, J. M. and P. I. Peterkin, ``Listeria monocytogenes, a
Food-borne Pathogen,'' Microbiology Review, 55:476-511, 1991.
3. FDA, Bad Bug Book (Foodborne Pathogenic Microorganisms and
Natural Toxins), 1999, Internet address: ``http://vm.cfsan.fda.gov/
mow/intro.html''.
4. Pinner, R. W., A. Schuchat, B. Swaminathan, P. S. Hayes, K.
A. Deaver, R. E. Weaver, B. D. Plikaytis, M. Reeves, C. V. Broome,
and J. D. Wenger, ``Role of Foods in Sporadic Listeriosis. 2.
Microbiologic and Epidemiologic Investigation,'' Journal of the
American Medical Association, 267:2046-2050, 1992.
5. CAST, ``Foodborne Pathogens,'' Council for Agricultural
Science and Technology, Task Force Report 122, Ames, IA, 1994.
6. Rocourt, J. and P. Cossart, ``Listeria monocytogenes,'' In
Food Microbiology, Fundamentals and Frontiers, edited by M. P.
Doyle, L. R. Beuchat, and T. J. Montville, ASM Press, Washington,
DC, 1997.
7. Miller, A. L., J. L. Smith, and G. A. Somkuti, ``Foodborne
Listeriosis,'' Soc. Indust. Microbiol., Elsevier, NY, 1990.
8. CDC, Morbidity and Mortality Weekly Report, ``Incidence and
Foodborne Illnesses-Foodnet,'' 47(37);782, 1997.
9. Farber, J. M., W. H. Ross, and J. Harwig, `` Health Risk
Assessment of Listeria monocytogenes in Canada,'' International
Journal of Food Microbiology, 30:145-156, 1996.
10. ICMSF, ``Choice of Sampling Plan and Criteria for Listeria
monocytogenes,'' International Journal of Food Microbiology, 22:83-
96, 1994.
11. IFST, Microbiological Criteria for Retail Foods,
Professional Food Microbiology Group, Inst. Food Science and
Technology, Lett. Appl. Microbiol, 20:331-332, 1995.
12. Health Canada, Compliance Guide/Policy on Listeria
monocytogenes in Ready-to-Eat Foods, 1994.
13. FSIS, Salmonella Enteritidis Risk Assessment, Shell Eggs and
Egg Products, USDA, FSIS, Washington, DC, 1998.
Dated: April 29, 1999.
William K. Hubbard,
Acting Director Commissioner for Policy.
[FR Doc. 99-11319 Filed 05-06-99; 8:45 am]
BILLING CODE 4160-01-F