Food Safety: Federal and State Response to the Spinach E. coli Outbreak

Food Safety: Federal and State Response to the Spinach E. coli Outbreak

Order Code RL33722
CRS Report for Congress
Received through the CRS Web
Food Safety:
Federal and State Response
to the Spinach E. coli Outbreak
November 13, 2006
Donna V. Porter
Specialist in Life Sciences
Domestic Social Policy Division
Sarah A. Lister
Specialist in Public Health and Epidemiology
Domestic Social Policy Division
Congressional Research Service ˜ The Library of Congress

Food Safety: Federal and State Response
to the Spinach E. coli Outbreak
Summary
In September 2006, the Food and Drug Administration (FDA) and the Centers
for Disease Control and Prevention (CDC) began receiving reports on clusters of
patients in various states confirmed to have E. coli infections. By early October, 199
people in 26 states had become ill — 102 had been hospitalized, 31 had developed
hemolytic uremic syndrome (HUS), a type of kidney failure, and three had died.
Escherichia coli O157:H7 (E. coli) is a bacterium found in animal feces that
causes diarrhea and abdominal cramps within days of exposure. An infection can
lead to HUS and, in some cases, death. Public health laboratories perform a type of
DNA fingerprinting to determine whether a sample taken from a patient matches
those taken from other patients and contaminated food during an outbreak. The time
from exposure to confirmation of an E. coli infection can take two to three weeks.
As the number of infections increased, an investigation that included FDA,
CDC, and state and local public health officials was launched. Starting on September
14 and continuing into early October, FDA and CDC released nearly daily statements
on the status of the investigation, alerting the public to the number of cases, states
with confirmed cases, spinach product recalls, agency actions, and consumer advice
on consumption of spinach products. Investigators were able to trace the outbreak
back to several farm fields in the Salinas Valley of California. While the
investigation continues, there is evidence that nearby livestock, feral pigs or other
environmental sources may have contaminated one or more of the fields.
Since the outbreak, FDA has advised growers of fresh produce that they need
to develop and implement voluntary guidelines to prevent outbreaks of food-borne
diseases. FDA has also announced that it will convene a public meeting on the issue
once the investigation is complete. Several growers groups have called for their
industry to use the best agricultural and processing practices to prevent such
outbreaks, not least because losses to the industry from the spinach outbreak have
been estimated at $100 million.
In October 2006, the House Committee on Energy and Commerce asked FDA
to explain its role in detecting contaminated food, particularly in the recent tainted
spinach case. The request sought details about the agency’s food safety procedures
used in emergency situations.
Both proponents and opponents of the National Uniformity for Food Act (S.
3128, H.R. 4167) have weighed in on how it would have affected the E. coli
outbreak. Opponents believe that states’ ability to act would have been compromised,
while proponents claim that the legislation would not have affected state adulteration
or inspection authorities.
Legislators may address the recent E. coli outbreak during reauthorization of the
farm bill in the 110th Congress, when the proposal for a single food safety agency
with increased powers may be considered.

Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
The Process of E. coli Case Confirmation . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
The Systems Used to Monitor Foodborne Illnesses . . . . . . . . . . . . . . . . . . . . 2
Timeline of Cases, Recalls, and Agency Actions . . . . . . . . . . . . . . . . . . . . . . . . . 3
Federal and State Tracking and Investigation . . . . . . . . . . . . . . . . . . . . . . . . 3
September 8, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
September 12, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
September 13, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
September 14, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
September 15, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
September 16, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
September 17, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
September 18, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
September 19, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
September 20, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
September 21, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
September 22, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
September 23, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
September 24, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
September 25, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
September 26, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
September 28, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
September 29, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
October 3, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
October 5, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
October 6, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
October 12, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Developments Following the Agency Alerts on the Outbreak . . . . . . . . . . 11
Related Congressional Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Final Observations
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
List of Figures
Figure 1. Cumulative Number of E. coli Cases Reported by CDC . . . . . . . . . . . . 9
Figure 2. Number of Confirmed E. coli Cases by State
as of October 6, 2006 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Food Safety: Federal and State Response
to the Spinach E. coli Outbreak
Introduction
In September 2006, government officials were alerted to an outbreak of E. coli
O157:H7 infections associated with the consumption of tainted fresh spinach. For
several weeks, the Food and Drug Administration (FDA) and the Centers for Disease
Control and Prevention (CDC) investigated the situation as additional cases were
identified nearly daily. This report details the events as they unfolded, and includes
the number of cases, the detection of the first case, and the process by which relevant
agencies acted as subsequent cases were reported. This report will be updated in
response to any further developments.
Background
The public first became aware of a new deadly strain of E. coli in 1982 during
an outbreak associated with ground beef. Escherichia coli is a bacterium normally
found in the intestines of humans and animals. Most strains of E. coli are harmless.
Several strains, including serotype O157:H7, may cause serious illness in humans,
though they are frequently found in livestock feces, particularly in cattle manure. In
humans, infection with E. coli O157:H7 can cause diarrhea that is often bloody and
accompanied by abdominal cramps. Fever may occur. Symptoms usually develop
in two to four days, but may emerge as quickly as a day or up to a week after
exposure. Healthy adults can generally recover completely from infection within a
week. Some individuals, however, especially young children and the elderly, can
develop hemolytic uremic syndrome (HUS) as a result of infection. HUS can lead
to serious kidney damage and even death. In terms of treatment, antibiotics are not
indicated and may be harmful. Due to the severity of illness, treatment of these
infections often requires hospitalization. Patients who experience kidney failure may
need dialysis. For the remainder of this report, “E. coli” will refer to the E. coli
O157:H7 strain implicated in the spinach outbreak.
The Process of E. coli Case Confirmation
The cases of E. coli linked to spinach consumption, as discussed in this report,
are “confirmed,” meaning that victims have been shown, by laboratory analysis of
specimens, to be infected with the organism. There are a number of reasons why
confirmation may not occur for all victims of an outbreak, though for serious
illnesses such as E. coli, the proportion of cases that are investigated with laboratory
testing is generally higher than with milder foodborne illness. The time from the
beginning of a patient’s illness to confirmation of whether the patient is part of an

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outbreak typically takes from two to three weeks. In the case of the E. coli outbreak
in spinach, the average time for confirmation of cases was about 15 days.1
In most cases of E. coli infection, public health laboratories in states and some
cities perform a type of DNA fingerprinting on E. coli samples. Investigators
determine whether the DNA fingerprinting pattern of the bacterium from one patient
is the same as that from other infected patients and from contaminated food. Bacteria
with the same DNA fingerprint are likely to have come from the same source.
A series of steps takes place between the point when a patient is infected and the
point when public health officials can confirm whether the patient is part of an E. coli
outbreak. As a result, there is generally a two- to three-week delay between the start
of the illness and confirmation of the patient’s connection to the outbreak.
This series breaks down as follows: In the case of E. coli, an incubation period
from the time of eating contaminated food to the beginning of the first symptoms is
typically two to four days. The time from the first symptom until the person seeks
medical care, when a diarrhea sample is collected for testing, is generally one to five
days. The process of laboratory diagnosis, which begins when a patient provides a
sample and E. coli is subsequently obtained from the sample, usually takes one to
three days. The time required to ship E. coli bacteria from a laboratory to state public
health authorities who will perform DNA fingerprinting may take up to a week,
depending on the transportation system within a state and the distance between a
clinical laboratory and public health department. The time required for state public
health officials to perform DNA fingerprinting on an E. coli sample and compare it
with an outbreak pattern is ideally one day. However, with limited staff and space
in public health laboratories during a period when other emergencies may occur, the
process can take up to four days.
State health departments typically report laboratory-confirmed cases of
foodborne illness to CDC on a regular basis. During serious interstate outbreaks such
as the E. coli outbreak linked to spinach, state health departments would typically
notify CDC of newly confirmed cases on a daily basis, to facilitate a swift nationwide
investigation. In general, disease reporting by states to CDC is voluntary, but it may
be required as a condition of federal funding for certain state public health systems,
such as the PulseNet system described below.
The Systems Used to Monitor Foodborne Illnesses
The tracking and reporting of foodborne illnesses are conducted in several ways:
! PulseNet is a national network of public health and food laboratories
coordinated by the CDC. The network consists of labs in state and
local health departments and federal agencies (CDC, FDA, and the
U.S. Department of Agriculture, or USDA). PulseNet experts
perform standardized DNA fingerprinting of foodborne disease-
1 CDC, “Timeline for Reporting of Cases with the Outbreak Strain of E. coli O157,” Sept.
19, 2006, at [http://www.cdc.gov/foodborne/ecolispinach/reportingtimeline.htm].

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causing bacteria by pulsed-field gel electrophoresis (PFGE). PFGE
can be used to distinguish among strains of organisms — for
example, E. coli O157:H7, Salmonella, Shigella, Listeria and
Campylobacter.2
! The OutbreakNet is a group of state public health officers who
investigate foodborne disease outbreaks and share information
throughout an outbreak.
! CDC’s Health Alert Network (HAN) is a national program that
provides vital health information and the infrastructure to support
dissemination of essential information to public health and medical
professionals at the state and local levels.
! The Epidemic Information Exchange (Epi-X) is CDC’s secure, Web-
based communications network that serves as a communications
exchange between CDC, state and local health departments, poison
control centers, and other public health professionals.
All of these systems have been used in the investigation of the recent E. coli
outbreak.
Timeline of Cases, Recalls, and Agency Actions3
Federal and State Tracking and Investigation
September 8, 2006. According to FDA and CDC reports, the agencies were
first alerted on September 8 to four cases of hemolytic uremic syndrome (HUS) in
a call from Wisconsin’s state epidemiologist. CDC began an investigation, working
collaboratively with state health departments and FDA, to detect infections, identify
the cause of the infections, and provide information to the public and health care
providers on the treatment and prevention of E. coli O157:H7 infections.
September 12, 2006. On September 12, the PulseNet system confirmed that
the E. coli O157:H7 strains from the patients in Wisconsin all had the same DNA
fingerprint pattern, and also identified the same pattern in some E. coli patients from
other states.
September 13, 2006. By September 13, CDC officials were alerted by
epidemiologists in Wisconsin and Oregon that fresh spinach was the suspected
source of small clusters of E. coli cases. The same day, Wisconsin and Oregon
epidemiologists were contacted by New Mexico epidemiologists about a cluster of
2 CDC, PulseNet home page, at [http://www.cdc.gov/pulsenet/index.htm].
3 The data in this section were taken from the daily alerts issued by FDA and CDC, available
at the following sites: [http://www.fda.gov/oc/opacom/hottopics/spinach.html] and
[http://www.cdc.gov/foodborne/ecolispinach/].

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E. coli infections that had also been associated with fresh spinach consumption. At
this point, the association of illness with spinach consumption was based only on
epidemiologic evidence: the common finding, among victims who were interviewed,
of a history of recent spinach consumption.
September 14, 2006. FDA and CDC issued the first of nearly three weeks
of daily consumer alerts about an E. coli outbreak in several states that was believed
to be associated with the consumption of fresh produce. At the time, preliminary
epidemiological evidence pointed to bagged fresh spinach as the possible cause of
the outbreak. FDA advised consumers to avoid consuming bagged spinach. (It is
notable that this product-wide advisory was made based solely on epidemiologic
evidence, since at this point, the outbreak organism had not yet been identified in any
spinach products.) The agencies advised individuals who believed that they had
experienced symptoms of illness after consuming bagged spinach to contact their
physicians, and physicians were urged to report suspected cases of E. coli infection
to local and state public health officials as soon as possible.
The federal agencies reported that they were working with state and local
agencies to determine the cause and scope of the outbreak. Eight states had reported
illnesses: Connecticut, Idaho, Indiana, Michigan, Oregon, New Mexico, Utah, and
Wisconsin. A total of 50 infected individuals had been identified — among them
were eight cases of HUS, one death, and multiple hospitalizations. The date range
of infection was estimated to be from August 25 to September 3, 2006.
September 15, 2006. On September 15, FDA and CDC issued
announcements that the outbreak of E. coli in multiple states had been associated
with the consumption of fresh spinach and fresh spinach-containing products. The
statements indicated that Natural Selection Foods LLC of San Juan Bautista,
California, had launched a voluntary recall of products that contained spinach marked
with “best if used by” dates of August 17 through October 1, 2006. (FDA does not
have authority to mandate recalls of most of the foods it regulates, including fresh
produce.) FDA reported that it was investigating whether eight other companies and
their brands were involved. The products under investigation, and subject to an
expanded consumer advisory, included spinach and any salad blend containing
spinach intended for retail or food service (restaurant and institutional) use. CDC
also noted that 94 cases of illness had been reported, and that 29 people (31%) had
been hospitalized, 14 (15%) had developed HUS, and one had died.
By this point, California, Kentucky, Maine, Minnesota, Nevada, New York,
Ohio, Pennsylvania, Tennessee, Virginia, Washington, and Wyoming had also
reported human infections to CDC, bringing the total number of affected states to 20.
Spinach from presumptively affected lots was also reported to have been distributed
in Canada and Mexico. The agencies also indicated that they, or state officials, were
testing available packages of spinach consumed by victims of E. coli infection.
September 16, 2006. On September 16, CDC reported that 102 cases of
illness due to E. coli infection had been confirmed, and that 52 people (51%) had
been hospitalized, 16 (16%) had developed HUS, and one had died. Tennessee was
removed from the list of states that had confirmed cases because a case originally

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attributed to the state had actually occurred in Kentucky. FDA advised consumers
to avoid fresh bagged spinach, and issued company recall information.
FDA also announced that it was expanding its lettuce safety initiative to cover
spinach. In response to repeated E. coli outbreaks associated with fresh lettuce, the
agency had advised growers in November 2005 of its concerns about the safety of
fresh greens, and the need for continued efforts to assure good agricultural and
processing practices within the industry.4 The California Department of Health
Services had expressed similar concerns in a letter to California growers in January
2006.5
September 17, 2006. On September 17, CDC reported that 109 cases of E.
coli infection had been confirmed, and that 55 people (50%) had been hospitalized,
16 (15%) had developed HUS, and one had died. FDA announced that a second
voluntary recall was under way by the company River Ranch of Salinas, California,
which was voluntarily recalling packages of spring mix obtained in bulk from
Natural Selection Foods. The FDA’s report listed all River Ranch and Natural
Selection brands.
September 18, 2006. On September 18, CDC reported that 114 cases of E.
coli had been confirmed, and that 60 people (53%) had been hospitalized, 18 (16%)
had developed HUS, and one had died. CDC added Illinois and Nebraska to the list
of states with confirmed cases, bringing the total to 21. The rest of the information
reported by CDC and FDA, which was repeated in subsequent notices, was the same
as on previous days: consumer advice, symptoms of illness, the two recalls, the
lettuce safety initiative and the ongoing investigation.
September 19, 2006. On September 19, CDC reported that the number of
E. coli cases reported had risen to 131, and that 66 people (50%) had been
hospitalized, 20 (15%) had developed HUS, and one had died. FDA stated that
products containing tainted spinach had been distributed to Taiwan, as well as to
Canada and Mexico (as noted above), but that no illnesses had been reported by those
countries.
September 20, 2006. On September 20, CDC reported that the number of
reported cases had increased to 146, and that 76 people (52%) had been hospitalized,
23 (16%) had developed HUS, and one had died. Arizona and Colorado had been
added to the list of states with confirmed cases, bringing the total to 23. FDA
expanded its consumer alert to include fresh spinach in bagged products, spinach in
a clamshell, and spinach from farmers’ markets. The agency also indicated that it
had found no evidence that spinach that was frozen, canned, or an ingredient in pre-
made meals manufactured by food companies was tainted. FDA reported a third
recall that had been announced by RLB Food Distributors, L.P., of West Caldwell,
4 FDA, “Nationwide E. coli O157:H7 Outbreak: Questions & Answers,” Sept. 16, 2006, at
[http://www.cfsan.fda.gov/~dms/spinacqa.html].
5 California Department of Health Services, “CDHS E. coli Information Website,” at
[http://www.dhs.ca.gov/opa/ecoli/].

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New Jersey, for certain listed salad products that may have contained spinach with
an “enjoy thru” date of September 20, 2006.
The agencies’ alerts also noted that the New Mexico Department of Health had
announced that through DNA fingerprinting, it had matched a strain of E. coli from
a victim’s package of spinach with the outbreak strain taken from infected patients.
This marked the first laboratory confirmation of the link between spinach
consumption and E. coli infections.
September 21, 2006. On September 21, CDC announced that 157 cases of
E. coli illness had been reported, and that 83 people (52%) had been hospitalized,
27 (17%) had developed HUS, and one had died. FDA reported that it was working
closely with the state of California, since it had been determined that the
contaminated spinach had come from fields in the California counties of Monterey,
San Benito, and Santa Clara. FDA alerts reassured consumers that processed spinach
(frozen and canned) and other produce from those counties were not implicated in
the outbreak. The same day, CDC held a Clinician’s Outreach and Communication
Activity (COCA) conference call with 800 people, who heard experts provide an
overview of the current outbreak and FDA’s investigation, the nature of E. coli as a
pathogen, and treatment options for patients exhibiting symptoms of the infection.
September 22, 2006. On September 22, CDC indicated that 166 cases of
illness had been reported, and that 88 people (53%) had been hospitalized, 27 (16%)
had developed HUS, and one had died. Maryland and Tennessee were added to the
list of states with confirmed cases, bringing the total to 25. FDA reported working
closely with the state of California in the three counties in which the tainted spinach
may have been grown — investigators were attempting to narrow the geographic area
suspected of being the source of the outbreak. FDA repeated the consumer notice
that processed spinach, spinach grown elsewhere in the United States, and other
produce grown in the three implicated counties were safe to eat, and that the food
industry was working to get fresh spinach back on the market.
September 23, 2006. On September 23, CDC announced that 171 cases of
E. coli infection had been reported, and that 92 people (54%) had been hospitalized,
27 (16%) had developed HUS, and one had died. In addition, FDA reported two
more voluntary recalls for products containing spinach supplied from Natural
Selection Foods of California. Triple B Corporation, doing business as S.T. Produce
of Seattle, Washington, recalled its fresh spinach products with “use by” dates of
August 22 through September 20, 2006, that had been distributed to retail stores in
Idaho, Montana, Oregon, and Washington, and sold in hard plastic clamshell
containers. Pacific Coast Fruits Company of Portland, Oregon, recalled products that
might contain spinach with “use by” dates of September 20, 2006, or earlier, and on
pizza products with dates of September 23, 2006, or earlier. The company reportedly
had stopped making all products with spinach supplied from California on September
14, 2006. Its products were shipped to Alaska, Idaho, Oregon, and Washington. For
the 25 states with confirmed cases, the number of cases was reported for each state.
Hong Kong was added to the list of places outside the U.S. that had received the
affected products.

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September 24, 2006. On September 24, CDC stated that 173 cases had been
reported, and that 92 people (53%) had been hospitalized, 28 (16%) had developed
HUS, and one had died. The agencies indicated that the Utah Department of Health
and the Salt Lake Valley Health Department had confirmed that E. coli O157:H7, the
same strain as the one associated with the outbreak, had been found in a bag of Dole
baby spinach purchased in Utah with a “use by” date of August 30, 2006. The tests
were conducted by the Utah Public Health Laboratory.
September 25, 2006. On September 25, CDC stated that 175 cases had been
reported, and that 93 people (53%) had been hospitalized, 28 (16%) had developed
HUS, and one had died. FDA reported that tainted products had been distributed to
Iceland.
September 26, 2006. On September 26, CDC reported that the number of
cases had increased to 183, and that 95 people (52%) had been hospitalized, 29
(16%) had developed HUS, and one had died. West Virginia was added to the list
of affected states, bringing the total to 26. CDC and FDA also announced that
Canada had reported one confirmed case of E. coli O157:H7 that matched the
outbreak strain. In addition, they noted that Pennsylvania Department of Health had
reported that the outbreak strain of E. coli O157:H7 had been isolated from a bag of
baby spinach.
September 28, 2006. On September 28, CDC reported that 187 cases
infected with the outbreak strain of E. coli had been reported, and that 97 people
(52%) had been hospitalized, 29 (16%) had developed HUS, and one had died.
September 29, 2006. On September 29, FDA announced that it had
determined that spinach implicated in the E. coli outbreak had been traced to Natural
Selection Foods LLC of San Juan Bautista, California. The determination was based
on epidemiologic and laboratory evidence obtained from multiple states (Colorado,
Ohio, Wisconsin, Nevada, Pennsylvania, Utah, New Mexico, and Illinois) and
analyzed by CDC, and on product distribution information. One company had
recalled its product on September 15 and four others had instituted secondary recalls,
because they received the recalled product from Natural Selection Foods. The
statement indicated that FDA, the state of California, CDC, and the US. Department
of Agriculture (USDA) were continuing to investigate the cause of the outbreak
through ongoing inspections and sample collections at facilities, in the environment
(including irrigation water sources), and through studies of local animal management
and water use.
The FDA update indicated that the Grower Shipper Association of Central
California, the Produce Marketing Association, the United Fresh Produce
Association, and the Western Growers Association had agreed to develop a voluntary
plan to improve the safety of fresh produce. FDA and the state of California,
however, have not ruled out the possibility of instituting regulatory requirements in
the future. In addition, FDA intends to convene a public meeting later in the year to
address the larger issue of food-borne illnesses linked to leafy greens once the current
investigation is complete.

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October 3, 2006. On October 3, CDC reported 192 cases of illness, and that
98 people (51%) had been hospitalized, 30 (16%) had developed HUS, and one died.
October 5, 2006. On October 5, FDA announced that the U.S. Attorney for
the Northern District of California had issued a statement on the execution of two
search warrants — for Growers Express in Salinas and Natural Selection Foods in
San Bautista, California — in connection with the outbreak of E. coli O157:H7 that
FDA had traced to spinach grown in the Salinas area. The U.S. Attorney stated that
there was no indication at that time that leaf spinach had been deliberately or
intentionally contaminated. FDA stated that it was working with the U.S. Attorney’s
office and the Federal Bureau of Investigation (FBI) to determine the facts behind the
outbreak, particularly allegations that certain spinach growers and distributors may
have failed to take all necessary precautions to ensure that their spinach was safe
before it was placed in interstate commerce. The number of reported cases of illness
had not changed.
October 6, 2006. On October 6, CDC announced that the number of reported
cases had increased to 199 (see Figure 1, below) — 102 people (51%) had been
hospitalized, and 31 (16%) had developed HUS. On this date, CDC also announced
that a total of three people had died in the outbreak — the single case announced
earlier, an elderly woman in Wisconsin; and two more victims with E. coli infections
that matched the outbreak strain on DNA fingerprinting, a child in Idaho and an
elderly woman in Nebraska. CDC also reported a fourth suspicious death in an
elderly woman in Maryland, but samples to confirm infection by DNA fingerprinting
were not available. The two confirmed deaths announced on this date had occurred
in September, but required additional time to link to the outbreak by DNA
fingerprinting. CDC reported additional findings as follows:
! Of the individuals affected by the outbreak, 141 (71%) were female
and 22 (11%) were children under the age of five.
! The proportions of individuals in each age group who developed
HUS included 29% of children under age 18, 8% of those aged 18
to 59, and 14 % of those who were 60 years or older.
! The cases were spread across 26 states: Arizona (8), California (2),
Colorado (1), Connecticut (3), Idaho (7), Illinois (2), Indiana (10),
Kentucky (8), Maine (3), Maryland (3), Michigan (4), Minnesota
(2), Nebraska (11), Nevada (2), New Mexico (5), New York (11),
Ohio (25), Oregon (6), Pennsylvania (10), Tennessee (1), Utah (19),
Virginia (2), Washington (3), West Virginia (1), Wisconsin (49), and
Wyoming (1). (See Figure 2, below).
In addition, FDA had determined, based on recall audits, that on September 15,
Kenter Canyon Farms, Inc., of Sun Valley, California, had instituted a voluntary
recall of repackaged spinach as part of the nationwide recall of Natural Selection
Foods. The recalled product was only distributed in California, and carried an
expiration date of September 20, 2006.

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October 12, 2006. On October 12, FDA and the state of California
announced test results from the field investigation of the outbreak of E. coli O157:H7
in spinach. Samples of cattle feces taken from one of the four implicated ranches
tested positive based on matching DNA fingerprints for the same strain that sickened
199 individuals. The announcement stated that while this finding was significant, it
was just one aspect of the trace-back investigation that was ongoing for FDA, the
state of California, CDC, and USDA. As of November 8, 2006, this alert was the
agencies’ most recent. (Readers should note that later news reports6 have indicated
that there were a total of 204 confirmed cases, but this number had not been verified
by any available agency documents as of November 8, 2006.)
Figure 1. Cumulative Number of E. coli Cases Reported by CDC
250
200
ted
c
fe
n
e I 150
eopl
P 100
of
ber
m
u
N
50
0
9/14 9/17 9/20 9/23 9/26 9/29 10/2 10/5 10/8 10/11 10/14 10/17
September and October 2006
Source: CDC and FDA data; compiled by CRS.
6 “Turning over a new leaf: Produce group wants farmers to foot the bill for inspections.”
The Sacramento Bee, October 31, 2006.

CRS-10
Figure 2. Number of Confirmed E. coli Cases by State as of October 6, 2006
ID
7
Source: Information provided by CDC. Map adapted by CRS.

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Developments Following the Agency Alerts on the Outbreak
On October 22, 2006, a statement issued by the United Fresh Produce
Association indicated that it understood that FDA had eliminated all concerns about
spinach grown anywhere outside of the three counties in California.7 The group
indicated its commitment to determining the specific source of the contamination and
working to prevent future outbreaks, including the use of the best agricultural
practices in the field and the strongest possible Hazard Analysis and Critical Control
Points (HACCP) programs in processing facilities.

The Center for Science in the Public Interest (CSPI) petitioned the state of
California to adopt stricter food safety procedures because the state has been at the
center of the E. coli outbreak, and has experienced other problems with
contamination of leafy greens.8 The petition calls for the California Department of
Health Services to establish mandatory regulations relating to manure and water
safety on farms, similar to those required of the meat and poultry industries. CSPI
suggested that the use of manure as fertilizer should be prohibited during growing
season, and that only drinkable water should be used in produce processing facilities.
On October 29, 2006, a news article reported that the investigation of the E. coli
spinach outbreak had been thorough, although there were no final answers yet.9 The
article indicated that the codes printed on the bags of spinach had reportedly led
detectives to discover when it had been bagged — on August 15 — and other specific
details, including worker shift and packing line. Exhaustive testing of the plants’
equipment and water supply over several weeks turned up none of the implicated
bacteria, according to government officials and company representatives. Company
records led investigators to the fields of nine farms in the three counties where the
spinach packed on August 15 had been grown. Coding on additional bags of
contaminated spinach allowed investigators to narrow the search to four fields. FDA
reported that the strain of E. coli had been found in manure on a cattle ranch in the
Salinas Valley, within a mile of spinach fields. Investigators combed the fields for
more samples, including wildlife and cattle feces, stream water, and spinach leaves.
Six samples taken from the ranch tested positive for the E. coli strain that was being
sought, including one found in the gut of a feral pig killed on the property. There
were also signs that feral pigs had broken through a wire mesh fence to reach the
spinach, indicating that the field was a likely source of the outbreak and that the wild
pigs were the probable carriers of the bacteria. However, other fields have not been
ruled out as the source. Nevertheless, this investigation has provided the most
specific information to date for how a microscopic organism commonly found in an
7 “Escherichia coli O157:H7 outbreak investigation narrows,” Medical Letter on the CDC
& FDA via NewsRx.com & NewRx.net, Oct. 22, 2006.
8 Center for Science in the Public Interest, “California urged to monitor farms for food
safety,” Oct. 25, 2006, at [http://www.cspinet.org/new/200610251.html].
9 “Spinach probe most thorough ever, but no clear answers yet,” The Associated Press, State
and Local Wire, Oct. 29, 2006.

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animal’s feces can cause illness and death in consumers thousands of miles away
from the primary source of the contamination.
On October 30, 2006, the Western Growers Association proposed that farmers
who grow leafy greens be subject to new food safety standards.10 While a detailed
plan has yet to be released, the statement indicated that soil, irrigation water, and
farm equipment should be tested for bacteria, workers should be trained in food
safety practices, and processing plants should be checked regularly. Violators could
be fined or banned from shipping. The association indicated that the produce
industry is subject to little oversight by state and federal regulators, an arrangement
that is believed to have led to the E. coli outbreak. Losses to the spinach industry
alone from the recent outbreak have been estimated to exceed $100 million.11
The association proposes to fund the food safety measures through the novel use
of a marketing order. Marketing orders were authorized by state and federal
legislation in 1937 as a way to compel producers of a particular crop to follow a
common set of rules and pay fees used to fund programs. While marketing orders
have never been used to enforce food safety, California Department of Food and
Agriculture officials have said that such procedures appear to be within the scope of
the law. No information is available on the cost of implementing such a program.
Although farmers have to approve marketing orders, they do seem to support the call
for increased regulation. The September 2006 outbreak represented the ninth
outbreak in California in a decade, and the 20th report of an E. coli outbreak in lettuce
or leafy greens nationwide since 1995. FDA has reportedly pressed the lettuce and
spinach growing industry for more than two years to follow voluntary federal
guidelines to prevent outbreaks of foodborne diseases.
On November 2, 2006, a rancher in San Benito County, California, revealed that
his operation was one of four farms under investigation by government agencies in
connection with the September 2006 E. coli outbreak.12 The rancher indicated that
his operation did not grow or process the spinach in question, but that he rented fields
to two tenants, one of whom was still under investigation as of November 8. Also
on November 2, the Canadian government lifted its ban on U.S. spinach that is grown
anywhere outside of San Benito and Monterey counties. Mexico had reportedly lifted
its ban on California-grown lettuce in October.
10 See: Western Growers Association, “Western Growers Board Takes Action To Require
Mandatory Food Safety Practices,” press release, Oct. 30, 2006, at [http://www.wga.com/
public/active/siteBuilder/templateNewsReleasePopup.php?id=70]; and “Turning over a new
leaf: Produce group wants farmers to foot the bill for inspections.” The Sacramento Bee,
Oct. 31, 2006.
11 Ibid.
12 One of four farms under investigation named. The Californian (Salinas, California), Nov.
2, 2006.

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On November 2, 2006, several major supermarkets told growers that they had
six weeks to establish new safety rules to prevent E. coli outbreaks.13 The
consortium of stores (Vons, Ralph’s, and Albertsons grocery chains, and the Costco
Wholesale Corporation) wanted growers to work with federal regulators, academia,
and industry research scientists to standardize food safety requirements. The group
also called for a process for updating food safety rules in response to the emergence
of research findings on how diseases are spread from the farm to the dinner table. If
growers failed to achieve more stringent and enforceable farming practices, the
consortium indicated that it was prepared to set up its own certification system.
Related Congressional Activities
On October 24, 2006, the House Committee on Energy and Commerce asked
FDA to explain its role in detecting contaminated food, particularly the E. coli strain
that tainted spinach in September 2006.14 The request asked for detailed information
about the agency’s food contamination preparedness and deterrence assessment,
conducted in 2004, and how the assessment was being used in emergencies like the
2006 E. coli outbreak. The committee’s letter asked the agency for the types of food
commodities selected for vulnerability assessments under its 2004 assessment,
known as the FDA Security Surveillance Assignment (FSSA), and how the data were
collected and analyzed. (FSSA was conducted to determine the safety of food at
special security events, such as the G-8 Summit and the national political
conventions.)
The recent E. coli outbreak led opponents of the National Uniformity for Food
Act (S. 3128, H.R. 4167), which is scheduled to come before the Senate in the
closing days of the 109th Congress, to call for a rejection of the bill. The Association
of Food and Drug Officials (AFDO) has indicated that states’ ability to react to future
bacterial outbreaks would be compromised. While FDA does not have authority to
mandate recalls for most of the foods it regulates, the states generally do have this
authority. Proponents of the bill argue that the legislation would not affect state
adulteration or inspection authorities. Supporters believe that state food regulators
are simply wrong to say that the legislation standardizing food warning labels would
have hindered states’ ability to recall spinach. See CRS Report RL33559, Food
Safety: National Uniformity for Food Act, by Donna V. Porter, for further
information.
13 “Grocers enter produce-safety debate: Big supermarket chains tell growers they have six
weeks to create rules to avoid E.coli outbreaks.” The Los Angeles Times, November 2, 2006.
14 House Committee on Energy and Commerce, “Oversight letter to the FDA concerning the
safety of the U.S. food supply and the adequacy of the FDA’s food safety and food security
efforts,”letter to Dr. Andrew C von Eschenbach, FDA Commissioner, Oct. 24, 2006, at
[http://energycommerce.house.gov/108/letters/letters.htm].

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The House and Senate Agriculture Committees may address the recent outbreak
of foodborne illness that occurred as a result of spinach contaminated by E. coli,
possibly from animal manure, when they take up reauthorization of the farm bill in
the 110th Congress. Some members have been longtime critics of the division of food
safety responsibilities between USDA, which regulates meat, poultry, and processed
egg products, and FDA, which regulates all other food products. A proposal for a
single food safety agency with increased powers may become part of the debate.
While not mentioned in FDA’s reports of its investigation, it is likely that the
investigation was streamlined as a result of certain new authorities granted to FDA
in comprehensive bioterrorism and public health preparedness legislation in the 107th
Congress. P.L. 107-188, the Public Health Security and Bioterrorism Preparedness
and Response Act of 2002, gave FDA the authority to require that food processing
facilities register with the agency, which had not been previously required. In
addition, processors were required to maintain records that FDA could use to
facilitate product trace-backs during outbreak investigations, including in their
records information about the source of ingredients coming into their facilities (“one
step back”) and the customers to whom they shipped products (“one step forward”).
Final Observations
The federal and state systems for tracking and investigating the bacterial
outbreak seem to have worked well once the clusters of E. coli infections were
recognized in several states. Investigators were able to trace back to the likely
location and source of the problem through a mix of epidemiologic and laboratory
investigation, and multi-agency coordination. The FDA and CDC provided alerts
to the public and to health officials, and continued to do so through daily updates.
In addition, CDC held a conference call for 800 health care professionals on the
investigation of the outbreak, E. coli testing, and treatment of patients.
A weak point in the system seems to be how best to intercept E. coli
contamination before it enters the food chain. While procedures are in place to
enhance the safety of meat products, the voluntary federal guidelines for leafy greens
seem to be ineffective or not fully implemented by growers and processors. Plans to
develop a more effective system announced by the produce industry may address this
weakness in the food chain. However, mandatory requirements may need to be
implemented by regulators to assure the public that leafy greens are safe for
consumption. While funding through market orders has been proposed by one group,
the question of whether this source of funding or another source is used remains to
be resolved. Oversight of the produce safety system will likely be needed.
In the final analysis, the specific cause of the California spinach E. coli outbreak
may never be known. Investigators were able to develop a fairly good idea of how
the contamination and outbreak occurred, thanks to identifying information on
bagged spinach, and DNA fingerprinting technology. While livestock and feral pigs
were shown to be carriers of the implicated E. coli strain, the precise pathway by

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which the spinach became contaminated is as yet unclear. Best agricultural practices
and HACCP in processing operations are likely to help in preventing such outbreaks
in the future.